Donald W McCarthy

Interests

No activities entered.

Courses

Scholarly Contributions

Journals/Publications

• McCarthy, D. W., Follette, K., Buxner, S. R., Dokter, E. F., Prather, E. E., Vezino, B., & Brock, L. S. (2017). The Quantitative Reasoning for College Science (QuaRCS) Assessment II: Demographic, Academic and Attitudinal Variables as Predictors of Quantitative Ability. Numeracy, 10(1), 33. doi:http://dx.doi.org/10.5038/1936-4660.10.1.5
• Leonard, D., Sheehan, P., McCarthy, D., Follette, K., Moustakas, J., Alaniz, M., Beaumont, C., Batterman, T., Black, E., Bowers, T., Cryder, M., Davis, C., Dawsey, R., Douglas, E., Gordon, S., Gramze, S., Greiner, M., Hart, K., Holt, A., , Hu, J., et al. (2016). Spectroscopic Classification of AT2016cvw as a normal Type Ia Supernova. The Astronomer's Telegram, 9173.
• McCarthy, D. W., Follette, K. B., Erin, D., Sanlyn, B., & Ed, P. (2015). The Quantitative Reasoning for College Science (QuaRCS) Assessment, 1: Development and Validation. Numeracy, 8(2), 41. doi:http://dx.doi.org/10.5038/1936-4660.8.2.2
• {Cesaroni}, R., {Massi}, F., {Arcidiacono}, C., {Beltr{\'a}n}, M., {Persi}, P., {Tapia}, M., {Molinari}, S., {Testi}, L., {Busoni}, L., {Riccardi}, A., {Boutsia}, K., {Bisogni}, S., {McCarthy}, D., , C. (2015). Star and jet multiplicity in the high-mass star forming region IRAS 05137+3919. \aap, 581, A124.
• {Follette}, K., {McCarthy}, D., {Dokter}, E., {Buxner}, S., , E. (2015). The Quantitative Reasoning for College Science (QuaRCS) Assessment, 1: Development and Validation. ArXiv e-prints.
• {Leonard}, D., {Sheehan}, P., {McCarthy}, D., {Follette}, K., {Moustakas}, J., {Cantillo}, D., {Cazares-Kelly}, A., {Cazares-Kelly}, S., {Cendes}, Y., {Damm}, N., {Donati}, A., {Douglas}, E., {Ferrell}, L., {Fosbiner-Elkins}, H., {Fox}, C., {Greenberg}, M., {Hart}, K., {Hensley}, H., {Holt}, A., , {Hooper}, E., et al. (2015). ASASSN-15lo is a Post-Maximum Normal Type Ia Supernova. The Astronomer's Telegram, 7675.
• {Leonard}, D., {Sheehan}, P., {McCarthy}, D., {Follette}, K., {Moustakas}, J., {Cantillo}, D., {Cazares-Kelly}, A., {Cazares-Kelly}, S., {Cendes}, Y., {Damm}, N., {Donati}, A., {Douglas}, E., {Ferrell}, L., {Fosbiner-Elkins}, H., {Fox}, C., {Greenberg}, M., {Hart}, K., {Hensley}, H., {Holt}, A., , {Hooper}, E., et al. (2015). ASASSN-15lu is a Type Ia Supernova. The Astronomer's Telegram, 7707.
• {Leonard}, D., {Sheehan}, P., {McCarthy}, D., {Follette}, K., {Moustakas}, J., {Cantillo}, D., {Cazares-Kelly}, A., {Cazares-Kelly}, S., {Cendes}, Y., {Damm}, N., {Donati}, A., {Douglas}, E., {Ferrell}, L., {Fosbiner-Elkins}, H., {Fox}, C., {Greenberg}, M., {Hart}, K., {Hensley}, H., {Holt}, A., , {Hooper}, E., et al. (2015). Optical Spectroscopy of PSN J15044078+1237436. The Astronomer's Telegram, 7690.
• {Leonard}, D., {Sheehan}, P., {McCarthy}, D., {Follette}, K., {Moustakas}, J., {Cantillo}, D., {Cazares-Kelly}, A., {Cazares-Kelly}, S., {Cendes}, Y., {Damm}, N., {Donati}, A., {Douglas}, E., {Ferrell}, L., {Fosbiner-Elkins}, H., {Fox}, C., {Greenberg}, M., {Hart}, K., {Hensley}, H., {Holt}, A., , {Hooper}, E., et al. (2015). PSN J11473508+5558147 is a Type Ib Supernova Near Maximum Light. The Astronomer's Telegram, 7680.
• {Monelli}, M., {Testa}, V., {Bono}, G., {Ferraro}, I., {Iannicola}, G., {Fiorentino}, G., {Arcidiacono}, C., {Massari}, D., {Boutsia}, K., {Briguglio}, R., {Busoni}, L., {Carini}, R., {Close}, L., {Cresci}, G., {Esposito}, S., {Fini}, L., {Fumana}, M., {Guerra}, J., {Hill}, J., , {Kulesa}, C., et al. (2015). The Absolute Age of the Globular Cluster M15 Using Near-infrared Adaptive Optics Images from PISCES/LBT.. \apj, 812, 25.
• {Ward-Duong}, K., {Patience}, J., {De Rosa}, R., {Bulger}, J., {Rajan}, A., {Goodwin}, S., {Parker}, R., {McCarthy}, D., , C. (2015). The M-dwarfs in Multiples (MINMS) survey - I. Stellar multiplicity among low-mass stars within 15 pc. \mnras, 449, 2618-2637.
• {Ward-Duong}, K., {Patience}, J., {De Rosa}, R., {Bulger}, J., {Rajan}, A., {Goodwin}, S., {Parker}, R., {McCarthy}, D., , C. (2015). VizieR Online Data Catalog: M-dwarfs in Multiples (MinMs) survey. I. (Ward-Duong+, 2015). VizieR Online Data Catalog, 744.
• {Wiggins}, P., {Masi}, G., {Brimacombe}, J., {Belligoli}, R., {Castellani}, F., {Marangoni}, C., {Leonard}, D., {Sheehan}, P., {McCarthy}, D., {Follette}, K., {Moustakas}, J., {Cantillo}, D., {Cazares-Kelly}, A., {Cendes}, Y., {Damm}, N., {Donati}, A., {Douglas}, E., {Ferrell}, L., {Fosbiner-Elkins}, H., , {Fox}, C., et al. (2015). Supernova 2015Q in NGC 3888 = Psn J11473508+5558147. Central Bureau Electronic Telegrams, 4128.
• Arcidiacono, C., Ragazzoni, R., Morossi, C., Franchini, M., Marcantonio, P. D., Kulesa, C., McCarthy, D., Briguglio, R., Xompero, M., Busoni, L., Quir\'os-Pacheco, F., Pinna, E., Boutsia, K., & Paris, D. (2014). A high-resolution image of the inner shell of the P Cygni nebula in the infrared [Fe II] line. \mnras, 443, 1142-1150.
• Cortini, G., James, N., Howerton, S., Masi, G., Leonard, D. C., Follette, K., Sheehan, P., McCarthy, D., Hart, S., Moustakas, J., Beverage, A., Burns, C., Chavez, W., Fox, A., Glad, E., Gregg, M., Griffin, Z., Griggs, J., Hart, K., , Holt, A., et al. (2014). Supernova 2014bv in NGC 4386 = Psn J12243098+7532086. Central Bureau Electronic Telegrams, 3911, 1.
• De Rosa, R. J., Patience, J., Ward-Duong, K., Vigan, A., Marois, C., Song, I., Macintosh, B., Graham, J. R., Doyon, R., Bessell, M. S., Lai, O., McCarthy, D. W., & Kulesa, C. (2014). The VAST Survey - IV. A wide brown dwarf companion to the A3V star $\zeta$ Delphini. \mnras, 445, 3694-3705.
• Dressing, C. D., Adams, E. R., Dupree, A. K., Kulesa, C., & McCarthy, D. (2014). Adaptive Optics Images. III. 87 Kepler Objects of Interest. \aj, 148, 78.
• Leonard, D. C., Follette, K., Sheehan, P., McCarthy, D., Hart, S., Moustakas, J., Beverage, A., Burns, C., Chavez, W., Fox, A., Glad, E., Gregg, M., Griffin, Z., Griggs, J., Hart, K., Holt, A., Hooper, E., Horning, A., Hou, L., , Irvin, N., et al. (2014). Spectroscopic classification of CSS140620:145423+013141. The Astronomer's Telegram, 6263, 1.
• Leonard, D. C., Follette, K., Sheehan, P., McCarthy, D., Hart, S., Moustakas, J., Beverage, A., Burns, C., Chavez, W., Fox, A., Glad, E., Gregg, M., Griffin, Z., Griggs, J., Hart, K., Holt, A., Hooper, E., Horning, A., Hou, L., , Irvin, N., et al. (2014). Spectroscopic classification of CSS140620:171007+610911 and CORRECTION of ATel \#6263. The Astronomer's Telegram, 6264, 1.
• Leonard, D. C., Follette, K., Sheehan, P., McCarthy, D., Hart, S., Moustakas, J., Beverage, A., Burns, C., Chavez, W., Fox, A., Glad, E., Gregg, M., Griffin, Z., Griggs, J., Hart, K., Holt, A., Hooper, E., Horning, A., Hou, L., , Irvin, N., et al. (2014). Spectroscopic classifications of ASASSN-14co and PSN J01505845+2159598. The Astronomer's Telegram, 6255, 1.
• Monard, L. A., Masi, G., Conseil, E., Leonard, D. C., Follette, K., Sheehan, P., McCarthy, D., Hart, S., Moustakas, J., Beverage, A., Burns, C., Chavez, W., Fox, A., Glad, E., Gregg, M., Griffin, Z., Griggs, J., Hart, K., Holt, A., , Hooper, E., et al. (2014). Supernova 2014bu in NGC 694 = Psn J01505845+2159598. Central Bureau Electronic Telegrams, 3910, 1.
• Sheehan, P., Follette, K., McCarthy, D., Leonard, D. C., Hart, S., Moustakas, J., Beverage, A., Burns, C., Chavez, W., Fox, A., Glad, E., Gregg, M., Griffin, Z., Griggs, J., Hart, K., Holt, A., Hooper, E., Horning, A., Hou, L., , Irvin, N., et al. (2014). Spectroscopic observations of PSN J12355235+2755563: Another likely LBV outburst. The Astronomer's Telegram, 6303, 1.
• Stone, J. M., Eisner, J. A., Salyk, C., Kulesa, C., & McCarthy, D. (2014). Variable Accretion Processes in the Young Binary-star System UY Aur. \apj, 792, 56.
• Ward-Duong, K., Patience, J., Rosa, R. D., Rajan, A., Hinz, P., Skemer, A., Morzinski, K., Males, J., Close, L. M., McCarthy, D. W., & Kulesa, C. (2014). A direct imaging study to search for and to characterize planetary mass companions. Proceedings of the International Astronomical Union, 8(S299), 74-75.
  More info

  Abstract: We present preliminary results from two parallel programs to search for new substellar companions to nearby, young M-stars and to characterize the atmospheres of known planetary mass and temperature substellar companions. For the M-star survey, we are analyzing high angular resolution archival data on systems within 15pc, complementing a subset with well-determined young ages based on measurements of several age indicators. The results include stellar and substellar companion candidates, which we are currently pursuing with follow-up second epoch images. The characterization component of the project involves using LBT LMIRCam and MMT ARIES direct imaging and spectroscopy data to investigate the atmospheres of known young substellar companions with masses overlapping the planetary regime. These atmospheric studies will represent an analogous comparison to the atmospheres of young imaged planets, and provide a means to fundamentally test evolutionary models, enhancing our understanding of the overall substellar population. Copyright © 2013, International Astronomical Union.
• Adams, E. R., Ciardi, D. R., Dupree, A. K., III, T. G., Kulesa, C., & McCarthy, D. (2013). Erratum: Adaptive optics images of kepler objects of interest (Astronomical Journal (2012) 144 (42)). Astronomical Journal, 146(3).
• Adams, E. R., Dupree, A. K., Kulesa, C., & McCarthy, D. (2013). Adaptive optics images. II. 12 kepler objects of interest and 15 confirmed transiting planets. Astronomical Journal, 146(1).
  More info

  Abstract: All transiting planet observations are at risk of contamination from nearby, unresolved stars. Blends dilute the transit signal, causing the planet to appear smaller than it really is, or producing a false positive detection when the target star is blended with an eclipsing binary. High spatial resolution adaptive optics images are an effective way of resolving most blends. Here we present visual companions and detection limits for 12 Kepler planet candidate host stars, of which 4 have companions within 4″. One system (KOI 1537) consists of two similar-magnitude stars separated by 0.″1, while KOI 174 has a companion at 0.″5. In addition, observations were made of 15 transiting planets that were previously discovered by other surveys. The only companion found within 1″ of a known planet is the previously identified companion to WASP-2b. An additional four systems have companions between 1″ and 4″: HAT-P-30b (3.″7, ΔKs = 2.9), HAT-P-32b (2.″9, ΔKs = 3.4), TrES-1b (2.″3, ΔKs = 7.7), and WASP-P-33b (1.″9, ΔKs = 5.5), some of which have not been reported previously. Depending on the spatial resolution of the transit photometry for these systems, these companion stars may require a reassessment of the planetary parameters derived from transit light curves. For all systems observed, we report the limiting magnitudes beyond which additional fainter objects located 0.″1-4″ from the target may still exist. © 2013. The American Astronomical Society. All rights reserved..
• Bulger, J., Hufford, T., Schneider, A., Patience, J., Song, I., Rosa, R. D., Rajan, A., Dowell, C. D., McCarthy, D., & Kulesa, C. (2013). Submillimeter observations of IRAS and WISE debris disk candidates. Astronomy and Astrophysics, 556.
  More info

  Abstract: A set of six debris disk candidates identified with IRAS or WISE excesses were observed at either 350 μm or 450 μm with the Caltech Submillimeter Observatory. Five of the targets - HIP 51658, HIP 68160, HIP 73512, HIP 76375, and HIP 112460 - have among the largest measured excess emission from cold dust from IRAS in the 25-100 μm bands. Single temperature blackbody fits to the excess dust emission of these sources predict 350-450 μm fluxes above 240 mJy. The final target - HIP 73165 - exhibits weak excess emission above the stellar photosphere from WISE measurements at 22 μm, indicative of a population of warm circumstellar dust. None of the six targets were detected, with 3σ upper limits ranging from 51-239 mJy. These limits are significantly below the expected fluxes from SED fitting. Two potential causes of the null detections were explored - companion stars and contamination. To investigate the possible influence of companion stars, imaging data were analyzed from new adaptive optics data from the ARIES instrument on the 6.5 m MMT and archival HST, Gemini NIRI, and POSS/2MASS data. The images are sensitive to all stellar companions beyond a radius of 1-94 AU, with the inner limit depending on the distance and brightness of each target. One target is identified as a binary system, but with a separation too large to impact the disk. While the gravitational effects of a companion do not appear to provide an explanation for the submm upper limits, the majority of the IRAS excess targets show evidence for contaminating sources, based on investigation of higher resolution WISE and archival Spitzer and Herschel images. Finally, the exploratory submm measurements of the WISE excess source suggest that the hot dust present around these targets is not matched by a comparable population of colder, outer dust. More extensive and more sensitive Herschel observations of WISE excess sources will build upon this initial example to further define the characteristics of warm debris disks sources. © ESO, 2013.
• Cesaroni, R., Massi, F., Arcidiacono, C., Beltrán, M., McCarthy, D., Kulesa, C., Boutsia, K., Paris, D., Quirós-Pacheco, F., & Xompero, M. (2013). A close-up view of a bipolar jet: Sub-arcsecond near-infrared imaging of the high-mass protostar IRAS 20126+4104. Astronomy and Astrophysics, 549.
  More info

  Abstract: Context. The formation of OB-type stars up to (at least) 140 M ⊙ can be explained via disk-mediated accretion and in fact growing observational evidence of disk-jet systems is found in high-mass star-forming regions. Aims. With the present observations we wish to investigate at sub-arcsecond resolution the jet structure close to the well studied high-mass protostar IRAS 20126+4104, which is known to be surrounded by a Keplerian disk. Methods. Adaptive optics imaging of the 2.2 μm continuum and H2 and Brγ line emission have been performed with the Large Binocular Telescope, attaining an angular resolution of ∼90 mas and an astrometric precision of ∼100 mas. Results. While our results are consistent with previous K-band images by other authors, the improved (by a factor ∼3) resolution allows us to identify a number of previously unseen features, such as bow shocks spread all over the jet structure. Also, we confirm the existence of a bipolar nebulosity within 1″ from the protostar, prove that the emission from the brightest, SE lobe is mostly due to the H2 line, and resolve its structure. Conclusions. Comparison with other tracers such as masers, thermal molecular line emission, and free-free continuum emission proves that the bipolar nebulosity is indeed tracing the root of the bipolar jet powered by the deeply embedded protostar at the center of the Keplerian disk. © 2013 ESO.
• Rachubo, A. A., Leonard, D. C., Follette, K., Sheehan, P., Bailey, V., McCarthy, D., Moustakas, J., Barrows, J., Bosset, E., Buckley, E., Burd, D., Calahan, J., Ceesay, I., Douglas, E., Feeney, C., Fornari, T., Fox, A., Fishwick, H., Gano, H., , Green, C., et al. (2013). Spectroscopy of PSN J00513484+2943149 in UGC 525. The Astronomer's Telegram, 5176, 1.
• Adams, E. R., Ciardi, D. R., Dupree, A. K., III, T. G., Kulesa, C., & McCarthy, D. (2012). Adaptive optics images of Kepler objects of interest. Astronomical Journal, 144(2).
  More info

  Abstract: All transiting planets are at risk of contamination by blends with nearby, unresolved stars. Blends dilute the transit signal, causing the planet to appear smaller than it really is, or produce a false-positive detection when the target star is blended with eclipsing binary stars. This paper reports on high spatial-resolution adaptive optics images of 90 Kepler planetary candidates. Companion stars are detected as close as 01 from the target star. Images were taken in the near-infrared (J and Ks bands) with ARIES on the MMT and PHARO on the Palomar Hale 200 inch telescope. Most objects (60%) have at least one star within 6″ separation and a magnitude difference of 9. Eighteen objects (20%) have at least one companion within 2″ of the target star; six companions (7%) are closer than 05. Most of these companions were previously unknown, and the associated planetary candidates should receive additional scrutiny. Limits are placed on the presence of additional companions for every system observed, which can be used to validate planets statistically using the BLENDER method. Validation is particularly critical for low-mass, potentially Earth-like worlds, which are not detectable with current-generation radial velocity techniques. High-resolution images are thus a crucial component of any transit follow-up program. © 2012. The American Astronomical Society. All rights reserved.
• Close, L. M., Puglisi, A., Males, J. R., Arcidiacono, C., Skemer, A., Guerra, J. C., Busoni, L., Brusa, G., Pinna, E., Miller, D. L., Riccardi, A., McCarthy, D. W., Xompero, M., Kulesa, C., Quiros-Pacheco, F., Argomedo, J., Brynnel, J., Esposito, S., Mannucci, F., , Boutsia, K., et al. (2012). High-resolution images of orbital motion in the Orion Trapezium cluster with the LBT AO system. Astrophysical Journal, 749(2).
  More info

  Abstract: The new 8.4m LBT adaptive secondary AO system, with its novel pyramid wavefront sensor, was used to produce very high Strehl (≳ 75% at 2.16 μm) near-infrared narrowband (Brγ: 2.16 μm and [Fe II]: 1.64 μm) images of 47young (∼1 Myr) Orion Trapezium θ 1 Ori cluster members. The inner ∼41 × 53″ of the cluster was imaged at spatial resolutions of ∼0″.050 (at 1.64 μm). A combination of high spatial resolution and high S/N yielded relative binary positions to ∼0.5 mas accuracies. Including previous speckle data, we analyze a 15year baseline of high-resolution observations of this cluster. We are now sensitive to relative proper motions of just ∼0.3 mas yr -1 (0.6kms -1 at 450 pc); this is a ∼7 × improvement in orbital velocity accuracy compared to previous efforts. We now detect clear orbital motions in the θ 1 Ori B 2 B 3 system of 4.9 ± 0.3kms -1 and 7.2 ± 0.8kms -1 in the θ 1 Ori A 1 A 2 system (with correlations of P.A. versus time at >99% confidence). All five members of the θ 1 Ori B system appear likely a gravitationally bound "mini-cluster." The very lowest mass member of the θ 1 Ori B system (B 4; mass ∼0.2 M ⊙) has, for the first time, a clearly detected motion (at 4.3 ± 2.0kms -1; correlation = 99.7%) w.r.t. B 1. However, B 4 is most likely in a long-term unstable (non-hierarchical) orbit and may "soon" be ejected from this "mini-cluster." This "ejection" process could play a major role in the formation of low-mass stars and brown dwarfs. © 2012. The American Astronomical Society. All rights reserved.
• Esposito, S., Mesa, D., Skemer, A., Arcidiacono, C., Claudi, R. U., Desidera, S., Gratton, R., Mannucci, F., Marzari, F., Masciadri, E., Close, L., Hinz, P., Kulesa, C., McCarthy, D., Males, J., Agapito, G., Argomedo, J., Boutsia, K., Briguglio, R., , Brusa, G., et al. (2012). LBT observations of the HR8799 planetary system â†: First detection of HR8799e in H band. Astronomy and Astrophysics, 549.
  More info

  Abstract: We have performed H and KS band observations of the planetary system around HR8799 using the new AO system at the Large Binocular Telescope and the PISCES Camera. The excellent instrument performance (Strehl ratios up to 80% in H band) enabled the detection of the innermost planet, HR8799e, at Hband for the first time. The H and KS magnitudes of HR8799e are similar to those of planets c and d, with planet e being slightly brighter. Therefore, HR8799e is likely slightly more massive than c and d. We also explored possible orbital configurations and their orbital stability. We confirm that the orbits of planets b, c and e are consistent with being circular and coplanar; planet d should have either an orbital eccentricity of about 0.1 or be non-coplanar with respect to b and c. Planet e can not be in circular and coplanar orbit in a 4:2:1 mean motion resonances with c and d, while coplanar and circular orbits are allowed for a 5:2 resonance. The analysis of dynamical stability shows that the system is highly unstable or chaotic when planetary masses of about 5M J for b and 7MJ for the other planets are adopted. Significant regions of dynamical stability for timescales of tens ofMyr are found when adopting planetary masses of about 3.5, 5, 5, and 5 MJ for HR8799b, c, d, and e respectively. These masses are below the current estimates based on the stellar age (30Myr) and theoretical models of substellar objects. © © ESO, 2012.
• Howell, S. B., Rowe, J. F., Bryson, S. T., Quinn, S. N., Marcy, G. W., Isaacson, H., Ciardi, D. R., Chaplin, W. J., Metcalfe, T. S., Monteiro, M. J., Appourchaux, T., Basu, S., Creevey, O. L., Gilliland, R. L., Quirion, P., Stello, D., Kjeldsen, H., Christensen-Dalsgaard, J., Elsworth, Y., , García, R. A., et al. (2012). KEPLER-21b: A 1.6 R _Earth planet transiting the bright oscillating F subgiant star HD179070. Astrophysical Journal, 746(2).
  More info

  Abstract: We present Kepler observations of the bright (V = 8.3), oscillating star HD179070. The observations show transit-like events which reveal that the star is orbited every 2.8days by a small, 1.6 R Earth object. Seismic studies of HD179070 using short cadence Kepler observations show that HD179070 has a frequency-power spectrum consistent with solar-like oscillations that are acoustic p-modes. Asteroseismic analysis provides robust values for the mass and radius of HD179070, 1.34 ± 0.06 M ⊙ and 1.86 ± 0.04 R ⊙, respectively, as well as yielding an age of 2.84 ± 0.34Gyr for this F5 subgiant. Together with ground-based follow-up observations, analysis of the Kepler light curves and image data, and blend scenario models, we conservatively show at the >99.7% confidence level (3σ) that the transit event is caused by a 1.64 0.04 R Earth exoplanet in a 2.785755 ± 0.000032day orbit. The exoplanet is only 0.04 AU away from the star and our spectroscopic observations provide an upper limit to its mass of ∼10 M Earth (2σ). HD179070 is the brightest exoplanet host star yet discovered by Kepler. © 2012. The American Astronomical Society. All rights reserved.
• Miller, D. L., Guerra, J. C., Boutsia, K., Fini, L., Argomedo, J., Biddick, C., Agapito, G., Arcidiacon, C., Briguglio, R., Brusa, G., Busoni, L., Esposito, S., Hill, J., Kulesa, C., McCarthy, D., Pinna, E., Puglisi, A. T., Quiros-Pacheco, F., Riccardi, A., & Xompero, M. (2012). Operation of the adaptive optics system at the large binocular telescope observatory. Proceedings of SPIE - The International Society for Optical Engineering, 8447.
  More info

  Abstract: The Adaptive Optics System at the Large Binocular Telescope Observatory consists of two Adaptive Secondary (ASM) mirrors and two Pyramid Wavefront sensors. The first ASM/Pyramid pair has been commissioned and is being used for science operation using the NIR camera PISCES on the right side of the binocular telescope. The left side ASM/Pyramid system is currently being commissioned, with completion scheduled for the Fall of 2012. We will discuss the operation of the first Adaptive Optics System at the LBT Observatory including interactions of the AO system with the telescope and its TCS, observational modes, user interfaces, observational scripting language, time requirement for closed loop and offsets and observing efficiency. © 2012 SPIE.
• Rodigas, T. J., Hinz, P. M., Leisenring, J., Vaitheeswaran, V., Skemer, A. J., Skrutskie, M., Y., K., Bailey, V., Schneider, G., Close, L., Mannucci, F., Esposito, S., Arcidiacono, C., Pinna, E., Argomedo, J., Agapito, G., Apai, D., Bono, G., Boutsia, K., , Briguglio, R., et al. (2012). The gray needle: Large grains in the HD15115 debris disk from LBT. Astrophysical Journal, 752(1).
  More info

  Abstract: We present diffraction-limited Ks band and L′ adaptive optics images of the edge-on debris disk around the nearby F2 star HD15115, obtained with a single 8.4m primary mirror at the Large Binocular Telescope. At the Ks band, the disk is detected at signal-to-noise per resolution element (SNRE) 3-8 from 1 to 25 (45-113AU) on the western side and from 12 to 21 (63-90AU) on the east. At L′ the disk is detected at SNRE 2.5 from 1 to 145 (45-90AU) on both sides, implying more symmetric disk structure at 3.8 μm. At both wavelengths the disk has a bow-like shape and is offset from the star to the north by a fewAU. A surface brightness asymmetry exists between the two sides of the disk at the Ks band, but not at L′. The surface brightness at the Ks band declines inside 1″ (45AU), which may be indicative of a gap in the disk near 1″. The Ks - L′ disk color, after removal of the stellar color, is mostly gray for both sides of the disk. This suggests that scattered light is coming from large dust grains, with 3-10 μm sized grains on the east side and 1-10 μm dust grains on the west. This may suggest that the west side is composed of smaller dust grains than the east side, which would support the interpretation that the disk is being dynamically affected by interactions with the local interstellar medium. © 2012. The American Astronomical Society. All rights reserved..
• Skemer, A. J., Hinz, P. M., Esposito, S., Burrows, A., Leisenring, J., Skrutskie, M., Desidera, S., Mesa, D., Arcidiacono, C., Mannucci, F., Rodigas, T. J., Close, L., McCarthy, D., Kulesa, C., Agapito, G., Apai, D., Argomedo, J., Bailey, V., Boutsia, K., , Briguglio, R., et al. (2012). First light LBT AO images of HR 8799 bcde at 1.6 and 3.3 μm: New discrepancies between young planets and old brown dwarfs. Astrophysical Journal, 753(1).
  More info

  Abstract: As the only directly imaged multiple planet system, HR 8799 provides a unique opportunity to study the physical properties of several planets in parallel. In this paper, we image all four of the HR 8799 planets at H band and 3.3μm with the new Large Binocular Telescope adaptive optics system, PISCES, and LBTI/LMIRCam. Our images offer an unprecedented view of the system, allowing us to obtain H and 3.3μm photometry of the innermost planet (for the first time) and put strong upper limits on the presence of a hypothetical fifth companion. We find that all four planets are unexpectedly bright at 3.3μm compared to the equilibrium chemistry models used for field brown dwarfs, which predict that planets should be faint at 3.3μm due to CH 4 opacity. We attempt to model the planets with thick-cloudy, non-equilibrium chemistry atmospheres but find that removing CH 4 to fit the 3.3μm photometry increases the predicted L′ (3.8μm) flux enough that it is inconsistent with observations. In an effort to fit the spectral energy distribution of the HR 8799 planets, we construct mixtures of cloudy atmospheres, which are intended to represent planets covered by clouds of varying opacity. In this scenario, regions with low opacity look hot and bright, while regions with high opacity look faint, similar to the patchy cloud structures on Jupiter and L/T transition brown dwarfs. Our mixed-cloud models reproduce all of the available data, but self-consistent models are still necessary to demonstrate their viability. © 2012 The American Astronomical Society. All rights reserved.
• Smith, J. D., Cushing, M., Barletta, A., McCarthy, D., Kulesa, C., & D., S. (2012). Eleven new heavily reddened field Wolf-Rayet stars. Astronomical Journal, 144(6).
  More info

  Abstract: We report the results of a medium-narrowband 2μm line survey covering 5.8deg 2 near the Galactic plane. We confirm 11 new field Wolf-Rayet stars along three lines of sight probing the inner Galaxy, demonstrating the capability to uncover distant and highly reddened populations of Galactic wind-borne emission-line stars suffering extinction as high as A V 40 and as distant as 9kpc down to modest magnitude limits of K s 12.5. All stars are of subtype WC7-8, with median distance d = 6kpc and median extinction = 2.5. Over the fields surveyed, the density of Wolf-Rayet stars to limiting magnitude K s 12.5 was found to be 1.9deg -2. We compare this to models which predict their distribution within the Galaxy and find that, even neglecting survey and subtype incompleteness, they consistently underpredict the number of newly discovered stars along the surveyed lines of sight. © 2012. The American Astronomical Society. All rights reserved..
• Bendek, E. A., Hart, M., Powell, K. B., Vaitheeswaran, V., McCarthy, D., & Kulesa, C. (2011). Latest GLAO results and advancements in laser tomography implementation at the 6.5m MMT telescope. Proceedings of SPIE - The International Society for Optical Engineering, 8149.
  More info

  Abstract: Laser tomography capability using a multi laser guide star (LGS) system is being implemented at the 6.5 m MMT telescope on Mt. Hopkins, AZ. The system uses five range-gated and dynamically refocused Rayleigh laser beacons to sense the atmospheric wavefront aberration. Corrections are then applied to the wavefront using the 336-actuator adaptive secondary mirror of the telescope. So far, the system has demonstrated successful control of ground-layer aberration over a field of view substantially wider than is delivered by conventional adaptive optics. In this paper, we report the latest results from this mode of operation, using for the first time a plate scale on our IR science camera that samples the diffraction scale at the Nyquist limit. We also discuss findings for a reduction in the width of the on-axis point-spread function from 1.07" to
• Borucki, W. J., Koch, D. G., Basri, G., Batalha, N., Brown, T. M., Bryson, S. T., Caldwell, D., Christensen-Dalsgaard, J., Cochran, W. D., DeVore, E., Dunham, E. W., Gautier, T. N., Geary, J. C., Gilliland, R., Gould, A., Howell, S. B., Jenkins, J. M., Latham, D. W., Lissauer, J. J., , Marcy, G. W., et al. (2011). Characteristics of planetary candidates observed by Kepler. II. Analysis of the first four months of data. Astrophysical Journal, 736(1).
  More info

  Abstract: On 2011 February 1 the Kepler mission released data for 156,453 stars observed from the beginning of the science observations on 2009 May 2 through September 16. There are 1235 planetary candidates with transit-like signatures detected in this period. These are associated with 997 host stars. Distributions of the characteristics of the planetary candidates are separated into five class sizes: 68 candidates of approximately Earth-size (Rp < 1.25 R⊕), 288 super-Earth-size (1.25 R⊕ ≤ R p < 2 R⊕), 662 Neptune-size (2 R ⊕ ≤ Rp < 6 R⊕), 165 Jupiter-size (6 R⊕ ≤ Rp < 15 R ⊕), and 19 up to twice the size of Jupiter (15 R ⊕ ≤ Rp < 22 R⊕). In the temperature range appropriate for the habitable zone, 54 candidates are found with sizes ranging from Earth-size to larger than that of Jupiter. Six are less than twice the size of the Earth. Over 74% of the planetary candidates are smaller than Neptune. The observed number versus size distribution of planetary candidates increases to a peak at two to three times the Earth-size and then declines inversely proportional to the area of the candidate. Our current best estimates of the intrinsic frequencies of planetary candidates, after correcting for geometric and sensitivity biases, are 5% for Earth-size candidates, 8% for super-Earth-size candidates, 18% for Neptune-size candidates, 2% for Jupiter-size candidates, and 0.1% for very large candidates; a total of 0.34 candidates per star. Multi-candidate, transiting systems are frequent; 17% of the host stars have multi-candidate systems, and 34% of all the candidates are part of multi-candidate systems. © 2011. The American Astronomical Society. All rights reserved.
• Buchhave, L. A., Latham, D. W., Carter, J. A., Désert, J., Torres, G., Adams, E. R., Bryson, S. T., Charbonneau, D. B., Ciardi, D. R., Kulesa, C., Dupree, A. K., Fischer, D. A., Fressin, F., Gautier, T. N., Gilliland, R. L., Howell, S. B., Isaacson, H., Jenkins, J. M., Marcy, G. W., , McCarthy, D. W., et al. (2011). Kepler-14b: A massive hot Jupiter transiting an F star in a close visual binary. Astrophysical Journal, Supplement Series, 197(1).
  More info

  Abstract: We present the discovery of a hot Jupiter transiting an F star in a close visual (03 sky projected angular separation) binary system. The dilution of the host star's light by the nearly equalmagnitude stellar companion (∼0.5mag fainter) significantly affects the derived planetary parameters, and if left uncorrected, leads to an underestimate of the radius and mass of the planet by 10% and 60%, respectively. Other published exoplanets, which have not been observed with high-resolution imaging, could similarly have unresolved stellar companions and thus have incorrectly derived planetary parameters. Kepler-14b (KOI-98) has a period of P = 6.790 days and, correcting for the dilution, has a mass of Mp = 8.40+0.35-0.34 M J and a radius of Rp = 1.136+0.073-0.054 R J, yielding a mean density of ρp = 7.1 ± 1.1 g cm-3. © 2011. The American Astronomical Society. All rights reserved.
• Demory, B., Seager, S., Madhusudhan, N., Kjeldsen, H., Christensen-Dalsgaard, J., Gillon, M., Rowe, J. F., Welsh, W. F., Adams, E. R., Dupree, A., McCarthy, D., Kulesa, C., Borucki, W. J., & Koch, D. G. (2011). The high albedo of the hot Jupiter Kepler-7b. Astrophysical Journal Letters, 735(1).
  More info

  Abstract: Hot Jupiters are expected to be dark from both observations (albedo upper limits) and theory (alkali metals and/or TiO and VO absorption). However, only a handful of hot Jupiters have been observed with high enough photometric precision at visible wavelengths to investigate these expectations. The NASA Kepler mission provides a means to widen the sample and to assess the extent to which hot Jupiter albedos are low. We present a global analysis of Kepler-7b based on Q0-Q4 data, published radial velocities, and asteroseismology constraints. We measure an occultation depth in the Kepler bandpass of 44 ± 5 ppm. If directly related to the albedo, this translates to a Kepler geometric albedo of 0.32 ± 0.03, the most precise value measured so far for an exoplanet. We also characterize the planetary orbital phase light curve with an amplitude of 42 ± 4 ppm. Using atmospheric models, we find it unlikely that the high albedo is due to a dominant thermal component and propose two solutions to explain the observed planetary flux. First, we interpret the Kepler-7b albedo as resulting from an excess reflection over what can be explained solely by Rayleigh scattering, along with a nominal thermal component. This excess reflection might indicate the presence of a cloud or haze layer in the atmosphere, motivating new modeling and observational efforts. Alternatively, the albedo can be explained by Rayleigh scattering alone if Na and K are depleted in the atmosphere by a factor of 10-100 below solar abundances. © 2011. The American Astronomical Society. All rights reserved.
• Bendek, E. A., Hart, M., Powell, K. B., Milton, N. M., Vaitheeswaran, V., McCarthy, D., Kulesa, C., Callahan, S., Ammons, S. M., & Rissmann, A. G. (2010). Status of the 6.5 m MMT telescope Laser Adaptive Optics system. Proceedings of SPIE - The International Society for Optical Engineering, 7736(PART 1).
  More info

  Abstract: The Laser Adaptive Optics system of the 6.5 m MMT telescope has now been commissioned with Ground Layer Adaptive Optics operations as a tool for astronomical science. In this mode the wavefronts sampled by each of five laser beacons are averaged, leading to an estimate of the aberration in the ground layer. The ground layer is then compensated by the deformable secondary mirror at 400 Hz. Image quality of 0.2-0.3 arc sec is delivered in the near infrared bands from 1.2-2.5 um over a field of view of 2 arc minutes. Tomographic wavefront sensing tests in May 2010 produced open loop data necessary to streamline the software to generate a Laser Tomography Adaptive Optics (LTAO) reconstructor. In addition, we present the work being done to achieve optimal control PID wavefront control and thus increase the disturbance rejection frequency response for the system. Finally, we briefly describe plans to mount the ARIES near infrared imager and echelle spectrograph, which will support the 2 arc min ground-layer corrected field and will exploit the diffraction limit anticipated with LTAO. ©2010 SPIE.
• Eisner, J. A., Doppmann, G. W., Najita, J. R., McCarthy, D., Kulesa, C., Swift, B. J., & Teske, J. (2010). Time-variable accretion in the TW Hya star/disk system. Astrophysical Journal Letters, 722(1 PART 2), L28-L32.
  More info

  Abstract: We present two epochs of observations of TW Hya from the high-dispersion near-IR spectrograph ARIES at the Multiple Mirror Telescope.We detect strong emission from the Brγ transition of hydrogen, indicating an accretion rate substantially larger than previously estimated, using hydrogen line emission. The Brγ line strength varies across our two observed epochs.We alsomeasure circumstellar-to-stellar flux ratios (i.e., veilings) that appear close to zero in both epochs. These findings suggest that TW Hya experiences episodes of enhanced accretion while the inner disk remains largely devoid of dust. We discuss several physical mechanisms that may explain these observations. © 2010 The American Astronomical Society. All rights reserved.
• Hart, M., Milton, N. M., Baranec, C., Powell, K., Stalcup, T., McCarthy, D., Kulesa, C., & Bendek, E. (2010). A ground-layer adaptive optics system with multiple laser guide stars. Nature, 466(7307), 727-729.
  More info

  PMID: 20686568;Abstract: To determine the influence of the environment on star formation, we need to study the process in the extreme conditions of massive young star clusters (∼104 solar masses) near the centre of our own Galaxy. Observations must be carried out in the near infrared because of very high extinction in visible light within the Galactic plane. We need high resolution to identify cluster members from their peculiar motions, and because most such clusters span more than 1, efficient observation demands a wide field of view. There is at present no space-based facility that meets all these criteria. Ground-based telescopes can in principle make such observations when fitted with ground-layer adaptive optics (GLAO), which removes the optical aberration caused by atmospheric turbulence up to an altitude of ∼500m (refs 7-10). A GLAO system that uses multiple laser guide stars has been developed at the 6.5-m MMT telescope, in Arizona. In previous tests, the system improved the resolution of the telescope by 30-50%, limited by wavefront error in the optics, but that was insufficient to allow rapid determination of cluster membership. Here we report observations of the core of the globular cluster M3 made after commissioning a sensor to monitor and remove slowly varying aberration in the optics. In natural seeing of 0.7, the point spread function at 2.2-μm wavelength was sharpened uniformly to 0.3 over a field of at least 2. The wide-field resolution was enhanced by a factor of two to three over previous work, with better uniformity, and extends to a wavelength of 1.2μm. Entire stellar clusters may be examined in a single pointing, and cluster membership can be determined from two such observations separated by just one year. © 2010 Macmillan Publishers Limited. All rights reserved.
• Rhoads, J. E., Malhotra, S., Scowen, P., Probst, R., & McCarthy, D. (2010). Multi-band filters for near-infrared astronomical applications. Proceedings of SPIE - The International Society for Optical Engineering, 7735(PART 1).
  More info

  Abstract: Filters for astronomical imaging traditionally have a simple bandpass that admits (more or less equally) all the photons within some bandwith Δλ around some central wavelength λ0. However, there are situations where not all photons are equally desirable. We plan to develop and apply multiband filters for practical astronomical application. A multiband filter is a bandpass filter whose transmission dips to zero at select, undesired wavelength ranges. Anticipated applications include (i) OH-suppressing filters, especially in the J band (λc ≈ 1.2μm); (ii) economy of filter slots through multi-band filters used in series with broad blocking filters; and (iii) efficient searches for object classes with highly structured spectra. We present the design and anticipated photometric properties of a prototype reduced-background JR filter, which we plan to buy and test in 2010. © 2010 Copyright SPIE - The International Society for Optical Engineering.
• Baranec, C., Hart, M., Milton, N. M., Stalcup, T., Powell, K., Snyder, M., Vaitheeswaran, V., McCarthy, D., & Kulesa, C. (2009). On-sky wide-field adaptive optics correction using multiple laser guide stars at the MMT. Astrophysical Journal, 693(2), 1814-1820.
  More info

  Abstract: We describe results from the first astronomical adaptive optics (AO) system to use multiple laser guide stars, located at the 6.5 m MMT telescope in Arizona. Its initial operational mode, ground-layer adaptive optics (GLAO), provides uniform stellar wave front correction within the 2′ diameter laser beacon constellation, reducing the stellar image widths by as much as 53%, from 070 to 033 at λ = 2.14 μm. GLAO is achieved by applying a correction to the telescope's adaptive secondary mirror that is an average of wave front measurements from five laser beacons supplemented with image motion from a faint stellar source. Optimization of the AO system in subsequent commissioning runs will further improve correction performance where it is predicted to deliver 01-02 resolution in the near-infrared during a majority of seeing conditions. © 2009. The American Astronomical Society. All rights reserved..
• Eriksen, K. A., Arnett, D., McCarthy, D. W., & Young, P. (2009). The reddening toward cassiopeia A's supernova: Constraining the ⁵⁶ni yield. Astrophysical Journal Letters, 697(1), 29-36.
  More info

  Abstract: We present new reddening measurements toward the young supernova remnant Cassiopeia A using two techniques not previously applied to this object. Our observations of the near-infrared [FeII] 1.257 μm and 1.644 μm lines show the extinction to be highly variable across the remnant, increasing toward the west and the south, consistent with previous radio and X-ray observations. While the absolute value of AV as determined by the [FeII] lines is uncertain due to conflicting calculations and observations of their intrinsic flux ratio, parts of the remnant without previous optical measurements show comparatively higher reddening. We find AV = 6.2 0.6 from the broadband shape of the infrared synchrotron emission of a knot within 13″ of the expansion center. Given this reddening, the apparent faintness of the nascent supernova, and iron mass constraints from X-ray observations, we estimate an ejected mass of 56Ni of 0.058-0.16 M. Taken with γ-ray observations of the 44Ti decay chain, this nickel mass is broadly consistent with the solar 44Ca/56Fe ratio. © 2009. The American Astronomical Society.
• Hart, M., Milton, N. M., Baranec, C., Stalcup, T., Powell, K., Bendek, E., McCarthy, D., & Kulesa, C. (2009). Wide field astronomical image compensation with multiple laser-guided adaptive optics. Proceedings of SPIE - The International Society for Optical Engineering, 7468.
  More info

  Abstract: We report closed-loop results obtained from the first adaptive optics system to deploy multiple laser guide beacons. The system is mounted on the 6.5 m MMT telescope in Arizona, and is designed to explore advanced altitude-conjugated techniques for wide-field image compensation. Five beacons are made by Rayleigh scattering of laser beams at 532 nm integrated over a range from 20 to 29 km by dynamic refocus of the telescope optics. The return light is analyzed by a unique Shack-Hartmann sensor that places all five beacons on a single detector, with electronic shuttering to implement the beacon range gate. Wavefront correction is applied with the telescope's unique deformable secondary mirror. The system has now begun operations as a tool for astronomical science, in a mode in which the boundary-layer turbulence, close to the telescope, is compensated. Image quality of 0.2-0.3 arc sec is routinely delivered in the near infrared bands from 1.2-2.5 μm over a field of view of 2 arc min. Although it does not reach the diffraction limit, this represents a 3 to 4-fold improvement in resolution over the natural seeing, and a field of view an order of magnitude larger than conventional adaptive optics systems deliver. We present performance metrics including images of the core of the globular cluster M3 where correction is almost uniform across the full field. We describe plans underway to develop the technology further on the twin 8.4 m Large Binocular Telescope and the future 25 m Giant Magellan Telescope. © 2009 SPIE.
• Milton, N. M., Hart, M. L., Baranec, C., Stalcup, T., Powell, K., McCarthy, D., Kulesa, C., & Hege, K. (2008). Commissioning of the MMT ground-layer and laser tomography adaptive optics systems. Proceedings of SPIE - The International Society for Optical Engineering, 7015.
  More info

  Abstract: A multi-laser adaptive optics system, at the 6.5 m MMT telescope, has been undergoing commissioning in preparation for wide-field, partially corrected as well as narrow-field, diffraction limited science observations in the thermal and near infrared. After several delays due to bad weather, we have successfully closed the full high order ground-layer adaptive optics (GLAO) control loop for the first time in February 2008 using five Rayleigh laser guide stars and a single tilt star. Characterization and automated correction of static aberrations such as non-common path errors were addressed in May 2008. Calibration measurements in preparation for laser tomography adaptive optics (LTAO) operation are planned for the fall of 2008 along with the start of shared-risk GLAO science observations. We present the results of GLAO observations with the PISCES imager, a 1 - 2.5 μm camera with a field of view of 110 arc seconds. The status of the remaining GLAO commissioning work is also reviewed. Finally, we present plans for commissioning work to implement the LTAO operating mode of the system.
• Biller, B. A., Close, L. M., Masciadri, E., Nielsen, E., Lenzen, R., Brandner, W., Mccarthy, D., Hartung, M., Kellner, S., Mamajek, E., Henning, T., Miller, D., Kenworthy, M., & Kulesa, C. (2007). An imaging survey for extrasolar planets around 45 close, young stars with the simultaneous differential imager at the very large telescope and MMT. Astrophysical Journal, Supplement Series, 173(1), 143-165.
  More info

  Abstract: We present the results of a survey of 45 young (≲250 Myr), close (≲50 pc) stars with the Simultaneous Differential Imager (SDI) implemented at the VLT and the MMT for the direct detection of extrasolar planets. As part of the survey, we observed 54 objects, consisting of 45 close, young stars; two more distant (
• Hergenrother, C. W., Mueller, B. E., Campins, H., Samarasinha, N. H., & McCarthy Jr., D. W. (2007). R- and J-band photometry of Comets 2P/Encke and 9P/Tempel 1. Icarus, 191(2 SUPPL.), 45-50.
  More info

  Abstract: Near-simultaneous R- and J-band photometric measurements of the short-period Comets 2P/Encke and the Deep Impact mission target 9P/Tempel 1 were obtained. The resulting R - J colors are + 0.82 ± 0.08   mag and + 1.46 ± 0.13   mag for Encke and Tempel 1, respectively. Tempel 1's color is redder than the solar R - J color index of +0.76. The Tempel 1 observations directly detected the nucleus while the Encke observations likely suffered from coma contamination. © 2005 Elsevier Inc. All rights reserved.
• McCarthy Jr., D. W., Stolovy, S. R., Campins, H., Larson, S., Samarasinha, N. H., & Kern, S. D. (2007). Comet Hale-Bopp in outburst: Imaging the dynamics of icy particles with HST/NICMOS. Icarus, 189(1), 184-195.
  More info

  Abstract: Comet Hale-Bopp was imaged at wavelengths from 1.87 to 2.22 μm by HST/NICMOS in post-perihelion observations starting on UT 1997 August 27.95. Diffraction-limited (∼0over(., ″)2) images were obtained at high signal-to-noise (∼1500) to probe the composition and dynamics of the inner coma and also the size and activity of the nucleus. The velocities of several unusual morphological features over a 1.7 h period, indicate that a significant outburst occurred 7.4 h prior to these images while the comet was at a heliocentric distance of 2.49 AU. Similar features are also apparent after re-analysis of pre-perihelion ground-based images. The inner coma (radius ≲ 2500   km) is dominated by an "arc" feature, which expanded and became more diffuse with time. This feature can be modeled as the bright central portion of a "jet of outburst" from a near-equatorial region of the nucleus. Less prominent, time-variable linear and circular morphologies are also apparent. The expansion rates of both the arc feature and the circular morphologies imply a common origin and also suggest a grain size distribution with two broad maxima. In addition, several static linear features extend to the edge of the field of view (21,100 km). Radial brightness profiles are highly asymmetric and only approach a ρ-1 decline at distances ≥15,000 km. Images in a narrow-band filter at 2.04 μm exhibit a ∼4% absorption feature relative to nearly simultaneous images at wavelengths of 2.22, 1.90, and 1.87 μm. This absorption is attributed to H2O ice in the coma grains. The spatial distribution and expansion velocity of the absorption at 2.04 μm indicate that these grains are associated with the outburst. The constancy of the absorption feature indicates no appreciable sublimation over 1.7 h. The unresolved nucleus has a flux density consistent with a 40 ± 10   km diameter assuming a 4% geometric albedo. © 2007 Elsevier Inc. All rights reserved.
• Biller, B. A., Close, L. M., Masciadri, E., Lenzen, R., Brandner, W., McCarthy, D., Henning, T., Nielsen, E. L., Hartung, M., Kellner, S., Geissler, K., & Kasper, M. (2006). Contrast limits with the Simultaneous Differential Extrasolar Planet Imager (SDI) at the VLT and MMT. Proceedings of SPIE - The International Society for Optical Engineering, 6272 II.
  More info

  Abstract: We discuss contrast limits obtained during a survey of young (10 mag, ΔH>10.6 mag for a T6 spectral type) at a separation of 0.5 from the primary star. With this degree of attenuation, we can image (5σ detection) a 2-4 Jupiter mass planet at 5 AU around a 30 Myr star at 10 pc. We are currently completing our survey of young, nearby stars. We have obtained complete datasets for 40 stars in the southern sky (VLT) and 11 stars in the northern sky (MMT). We believe that our SDI images are the highest contrast astronomical images ever made from ground or space for methane rich companions.
• Hergenrother, C. W., Mueller, B. E., Campins, H., Samarasinha, N. H., & McCarthy Jr., D. W. (2006). R- and J-band photometry of Comets 2P/Encke and 9P/Tempel 1. Icarus, 181(1), 156-161.
  More info

  Abstract: Near-simultaneous R- and J-band photometric measurements of the short-period Comets 2P/Encke and the Deep Impact mission target 9P/ Tempel 1 were obtained. The resulting R-J colors are +0.82 ± 0.08 mag and +1.46 ± 0.13 mag for Encke and Tempel 1, respectively. Tempel 1's color is redder than the solar R-J color index of +0.76. The Tempel 1 observations directly detected the nucleus while the Encke observations likely suffered from coma contamination. © 2005 Elsevier Inc. All rights reserved.
• Huard, T. L., Myers, P. C., Murphy, D. C., Crews, L. J., Lada, C. J., Bourke, T. L., Crapsi, A., J., N., Mccarthy Jr., D. W., & Kulesa, C. (2006). Deep near-infrared observations of L1014: Revealing the nature of the core and its embedded source. Astrophysical Journal Letters, 640(1 I), 391-401.
  More info

  Abstract: Recently, the Spitzer Space Telescope discovered L1014-IRS, a mid-infrared source with protostellar colors, toward the heretofore "starless" core L1014. We present deep near-infrared observations that show a scattered light nebula extending from L1014-IRS. This nebula resembles those typically associated with protostars and young stellar objects, tracing envelope cavities presumably evacuated by an outflow. The northern lobe of the nebula has an opening angle of ∼100°, while the southern lobe is barely detected. Its morphology suggests that the bipolar cavity and inferred protostellar disk are not inclined more than 30° from an edge-on orientation. The nebula extends at least 8″ from the source at KS, strongly suggesting that L1014-IRS is embedded within L1014 at a distance of 200 pc rather than in a more distant cloud associated with the Perseus arm at 2.6 kpc. In this case, the apparently low luminosity of L1014-IRS, 0.090 L⊙, is consistent with it having a substellar mass. However, if L1014-IRS is obscured by a circumstellar disk, its luminosity and inferred mass may be greater. Using near-infrared colors of background stars, we investigate characteristics of the L1014 molecular cloud core. We determine a mass of 3.6M⊙ for regions of the core with AV ≥ 2 mag. A comparison of the radial extinction profile of L1014 with other cores suggests that L1014 may be among the most centrally condensed cores known, perhaps indicative of the earliest stages of brown dwarf or star formation processes. © 2006. The American Astronomical Society. All rights reserved.
• Andersen, M., Meyer, M. R., Greissl, J., Oppenheimer, B. D., Kenworthy, M. A., McCarthy, D. W., & Zinnecker, H. (2005). The IMF in extreme star-forming environments: Searching for variations vs. initial conditions. Proceedings of the International Astronomical Union, 1, 285-290.
  More info

  Abstract: Any predictive theory of star formation must explain observed variations (or lack thereof) in the initial mass function. Recent work suggests that we might expect quantitative variations in the IMF as a function of metallicity (Larson 2005) or magnetic field strength (Shu et al. 2004). We summarize results from several on-going studies attempting to constrain the ratio of high to low mass stars, as well as stars to sub- stellar objects, in a variety of different environments, all containing high mass stars. First, we examine the ratio of stars to sub-stellar objects in the nearby Mon R2 region utilizing NICMOS/HST data. We compare our results to the IMF by Kroupa (2002) and to the observed ratios for IC 348 and Orion. Second, we present preliminary results for the ratio of high to low mass stars in W51, the most luminous H II region in the galaxy. Based on ground-based multicolour images of the cluster obtained with the MMT adaptive optics system, we derive a lower limit to the ratio of high-mass to low-mass stars and compare it to the ratios for nearby clusters. Finally, we present the derived IMF for the R136 region in the LMC where the metallicity is 1/4 solar using HST/NICMOS data. We find that the IMF is consistent with that characterizing the field (Chabrier 2003), as well as nearby star-forming regions, down to 1.0 M⊙ outside 2 pc. Whereas the results for both Mon R2 and R136 are consistent with the nearby clusters, the ratio of high to low mass stars in W51 tentatively indicates a lack of low-mass objects. © 2005 International Astronomical Union.
• Biller, B. A., Close, L. M., Lenzen, R., Brandner, W., McCarthy, D., Nielsen, E., Kellner, S., & Hartung, M. (2005). Suppressing speckle noise for simultaneous differential extrasolar planet imaging (SDI) at the VLT and MMT. Proceedings of the International Astronomical Union, 1, 571-575.
  More info

  Abstract: We discuss the instrumental and data reduction techniques used to suppress speckle noise with the Simultaneous Differential Imager (SDI) implemented at the VLT and the MMT. SDI uses a quad filter to take images simultaneously at 3 wavelengths surrounding the 1.62 μm methane bandhead found in the spectrum of cool brown dwarfs and gas giants. By performing a difference of images in these filters, speckle noise from the primary can be significantly attenuated, resulting in photon noise limited data. Non-trivial data reduction tools are necessary to pipeline the simultaneous differential imaging. Here we discuss a custom algorithm implemented in IDL to perform this reduction. The script performs basic data reduction tasks but also precisely aligns images taken in each of the filters using a custom shift and subtract routine. In our survey of nearby young stars at the VLT and MMT (see Biller et al, this conference), we achieved H band contrasts >25000 (5σ ΔF1(1.575 μm) >10.0 mag, ΔH > 11.5 mag for a T6 spectral type object) at a separation of 0.5″ from the primary star. We believe that our SDI images are among the highest contrast astronomical images ever made from ground or space for methane rich companions. © 2006 International Astronomical Union.
• Biller, B. A., Close, L. M., Masciadri, E., Lenzen, R., Brandner, W., McCarthy, D., Henning, T., Nielsen, E., & Hartung, M. (2005). A survey of close, young stars with SDI at the VLT and MMT. Proceedings of the International Astronomical Union, 1, 53-60.
  More info

  Abstract: We discuss the preliminary results of a survey of young (10 mag, ΔH>11.5 mag for a T6 spectral type) at a separation of 0.5″ from the primary star. With this degree of attenuation, we should be able to image (5σ detection) a 2-4 Jupiter mass planet at 5 AU around a 30 Myr star at 10 pc. We are currently completing our survey of young, nearby stars, with complete datasets for 35 stars in the southern sky (VLT) and 7 stars in the northern sky (MMT). We believe that our SDI images are the highest contrast astronomical images ever made from ground or space for methane rich companions. © 2006 International Astronomical Union.
• Finn, R. A., Zaritsky, D., McCarthy Jr., D. W., Poggianti, B., Rudnick, G., Halliday, C., Milvang-Jensen, B., Pelló, R., & Simard, L. (2005). Hα-derived star formation rates for three z ≃ 0.75 EDisCS galaxy clusters. Astrophysical Journal Letters, 630(1 I), 206-227.
  More info

  Abstract: We present Hα-derived SFRs for three z ≃ 0.75 galaxy clusters. Our 1 σ flux limit corresponds to a star formation rate (SFR) of 0.10-0.24 h100-2M⊙ yr-1, and our minimum reliable Hα + [N II] rest-frame equivalent width is 10 Å. We show that Hα narrowband imaging is an efficient method for measuring star formation in distant clusters. In two out of three clusters, we find that the fraction of star-forming galaxies increases with projected distance from the cluster center. We also find that the fraction of star-forming galaxies decreases with increasing local galaxy surface density in the same two clusters. We compare the median rate of star formation among star-forming cluster galaxies to a small sample of star-forming field galaxies from the literature and find that the median cluster SFRs are ∼50% less than the median field SFR. We characterize cluster evolution in terms of the mass-normalized integrated cluster SFR and find that the z ≃ 0.75 clusters have more SFR per cluster mass on average than the z ≤ 0.4 clusters from the literature. The interpretation of this result is complicated by the dependence of the mass-normalized SFR on cluster mass and the lack of sufficient overlap in the mass ranges covered by the low- and high-redshift samples. We find that the fraction and luminosities of the brightest starburst galaxies at z ≃ 0.75 are consistent with their being progenitors of the poststarburst galaxies at z ≃ 0.45 if the poststarburst phase lasts several (∼5) times longer than the starburst phase. © 2005. The American Astronomical Society. All rights reserved.
• Biller, B. A., Close, L., Lenzen, R., Brandner, W., McCarthy, D., Nielsen, E., & Hartung, M. (2004). Suppressing speckle noise for simultaneous differential extrasolar planet imaging (SDI) at the VLT and MMT. Proceedings of SPIE - The International Society for Optical Engineering, 5490(PART 1), 389-397.
  More info

  Abstract: We discuss data reduction techniques and results from the Simultaneous Differential Imager (SDI) implemented at the VLT (Lenzen et al. 2004a) and the MMT. SDI uses a quad filter to take images simultaneously at 3 wavelengths surrounding the 1.62 μm methane bandhead found in the spectrum of cool brown dwarfs and gas giants. By performing a difference of images in these filters, speckle noise from the primary can be attenuated by a factor of >10 2. Non-trivial data reduction tools are necessary to pipeline the simultaneous differential imaging. Here we discuss a custom algorithm implemented in IDL to perform this reduction. The script performs basic data reduction tasks but also precisely aligns images taken in each of the filters using a custom shift and subtract routine. In our commissioning runs at the VLT and MMT, we achieved contrasts up to a factor of 45000 (ΔH=11.7) at a separation of 0.6" from the primary star. With this degree of attenuation, we should be able to image a 2-4 Jupiter mass planet at 5 AU around a 30 Myr star at 10 pc. We believe that our SDI images are the highest contrast astronomical images ever made from ground or space.
• Finn, R. A., Zaritsky, D., & McCarthy Jr., D. W. (2004). Hα-derived star formation rates for the z = 0.84 galaxy cluster Cl J0023+0423B. Astrophysical Journal Letters, 604(1 I), 141-152.
  More info

  Abstract: We present Hα-derived star formation rates (SFRs) for the galaxy cluster Cl J0023+0423B at z = 0.845. Our 3 σ flux limits correspond to an SFR of 0.24 h100-2 M⊙ yr-1, and our minimum reliable Hα + [N II] equivalent width is greater than 10 Å, demonstrating that near-infrared narrowband imaging can sample the star-forming galaxy population in distant clusters. Comparison with spectroscopy shows that the number of false detections is low (9% ± 6%) and that our Hα equivalent widths are correlated with spectroscopically determined [O II] equivalent widths. A magnitude-limited spectroscopic survey conducted over the same area missed 70% of the star-forming galaxies and 65% of the integrated star formation. Using Hubble Space Telescope Wide Field Planetary Camera 2 Archive images, we fit Sersic profiles to all galaxies with significant narrowband equivalent widths and find that equivalent width decreases as the steepness of galaxy profile increases. We find no significant population of early-type galaxies with ongoing star formation. The integrated SFR per cluster mass of Cl J0023+0423B is a factor of 10 higher than that of the three z ∼ 0.2 clusters in the literature with available Hα observations. A larger sample of z ∼ 0.8 clusters spanning a range of cluster masses is needed to determine whether this variation is due to a difference in cluster mass or redshift.
• Kenworthy, M. A., Miller, D. L., Brusa, G., Hinz, P. M., Fisher, D. L., Lloyd-Hart, M., Wildi, F. P., McCarthy Jr., D. W., Curley, D. L., Kulesa, C., Young, P. A., Oppenheimer, B. D., Liu, W., Meyer, M. R., & Greissl, J. (2004). Scientific results from the MMT Natural Guide Star Adaptive Optics system. Proceedings of SPIE - The International Society for Optical Engineering, 5490(PART 1), 351-358.
  More info

  Abstract: The Natural Guide Star Adaptive Optics (NGS AO) system for the MMT Observatory is currently the only AO system in the world that uses a deformable secondary mirror to provide wavefront correction. This approach has unique advantages in terms of optical simplicity, high throughput and low emissivity. Here we present selected scientific results from the past year and a half of operation. Research with the AO system ranges from small scale structure around planetary nebulae, low mass stellar systems in the near IR, through to nulling interferometry in the mid infra-red.
• Mueller, B. E., Hergenrother, C. W., Samarasinha, N. H., Campins, H., & McCarthy Jr., D. W. (2004). Simultaneous visible and near-infrared time resolved observations of the outer Solar System object (29981) 1999 TD₁₀. Icarus, 171(2), 506-515.
  More info

  Abstract: The outer Solar System object (29981) 1999 TD10 was observed simultaneously in the R, and J and H bands in September 2001, and in B, V, R, and I in October 2002. We derive B-V=0.80 ±0.05 mag, V-R=0.48±0.05 mag, R-I=0.44±0.05 mag, R-J=1.24±0.05 mag, and J-H=0.61±0.07 mag. Combining our data with the data from Rousselot et al. (2003, Astron. Astrophys. 407, 1139) we derive a synodic period of 15.382±0.001 hr in agreement with the period from Rousselot et al. Our observations at the same time, with better S/N and seeing, show no evidence of a coma, contrary to the claim by Choi et al. (2003, Icarus 165, 101). © 2004 Elsevier Inc. All rights reserved.
• Stolovy, S., Melia, F., Mccarthy, D., & Yusef-Zadeh, F. (2003). Near-Infrared Flux Limits for Sgr A* Based on NICMOS Data. Astronomische Nachrichten, 324(SUPPL.1), 419-423.
  More info

  Abstract: Images of the central arcsec of the Galaxy at near-infrared(IR) wavelengths reveal a tight stellar cluster, however, no point source exactly coincident with the radio source Sgr A* has been clearly detected in the near-IR. "Contaminating" emission due to overlapping point spread functions (PSFs) from this stellar cluster as well as from the bright IRS16 sources 1-3″ away from Sgr A* makes it difficult to assess directly the near-IR characteristics of Sgr A*. Taking advantage of the stability of the PSF achieved by HST/NICMOS observations, we employ PSF subtraction techniques in order to investigate the true nature of the near-IR emission from Sgr A*. New limits on the maximum possible flux emanating from a point source coincident with Sgr A* are presented at 1.1, 1.45, 1.6, 1.9, and 2.2 μm based on NICMOS data taken at several epochs. These are the faintest reported near-IR flux limits for wavelengths shorter than 2.2 μm. The resulting extinction-corrected .uxes are compared to theoretical models (including both quiescent and flare models) for the spectrum of Sgr A*. We also present NICMOS narrow-band emission line images in Paα where signi.cant stellar PSF residuals have been removed to reveal new diffuse structures in the ionized gas near Sgr A* at two epochs. © 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
• Freed, M., Close, L. M., McCarthy, D. W., & Rademacher, M. (2002). MEDI: An instrument for direct-detection of massive extrasolar planets. Proceedings of SPIE - The International Society for Optical Engineering, 4839(2), 1132-1141.
  More info

  Abstract: We have developed an instrument, MEDI (Massive Exoplanet Differential Imager), that takes advantage of a unique method of starlight rejection, simultaneous differential imaging, in order to directly image massive planets around nearby stars. Using this technique we expect to achieve suppression of starlight to the photon-noise limit, which means that increased exposure time will translate into higher sensitivities. This is in contrast to past sequential and two-color simultaneous studies that reach a sensitivity floor due to speckle-noise limitations. MEDI is currently installed in ARIES, the infrared camera that will be commissioned at the newly refurbished 6.5m MMT in January 2003, with the world's first adaptive secondary. This should allow us to take Nyquist sampled, diffraction-limited images in the near-IR. The adaptive secondary will also give us unprecedented throughput while minimizing the thermal background and providing a smooth PSF. Based on lab results, we expect to be able to detect objects 106 times fainter than their primaries at 0.5″ separations in 2 hours, limited only by photon noise. This suggests that we will be sensitive to objects with masses as small as ∼ 5 MJupiter at separations of greater than ∼ 5 AU for G2 V stars that are ∼ 300 Myr old and within about 10 pc. Therefore, we will probe a unique search space compared with current radial velocity methods, which are so far restricted to close-in (< 6 AU) orbits.
• Heinze, A. N., Hinz, P. M., & McCarthy, D. W. (2002). A 3-5 micron camera for extrasolar planet searches. Proceedings of SPIE - The International Society for Optical Engineering, 4839(2), 1154-1164.
  More info

  Abstract: We have designed and built an infrared camera using a Rockwell HAWAII MBE array sensitive from 1-5 microns. This camera is optimized for sensitive imaging in the 3-5 micron wavelength range, i.e. the L' and M photometric bands. When used with the deformable secondary adaptive optics (AO) system on the 6.5m MMT telescope, the camera will be ideal for direct imaging surveys for extrasolar planets around young, nearby stars. Based on the models of Burrows et al (2001), we calculate that in a 2-hour background-limited integration with MMT AO we will be able to detect, in both M and V bands, a planet of 1 billion year (Gyr) age and 5 Jupiter masses (MJ) at a distance of 10 parsecs (pc). Our simulations of atmospheric speckle noise suggest that background limited M and L' observations are possible at about 1.5 and 2.5 arcseconds, respectively, from a solar-type star at 10pc distance. The speckle limits move inward dramatically for fainter stars, and brighter planets or brown dwarfs can be seen even where the speckles overwhelm the background noise. The camera opens up a region of parameter space that is inaccessible to the radial velocity technique, and thus the two methods are highly complementary.
• Hinz, J. L., McCarthy Jr., D. W., Simons, D. A., Henry, T. J., Kirkpatrick, J. D., & McGuire, P. C. (2002). A near-infrared, wide-field, proper-motion search for brown dwarfs. Astronomical Journal, 123(4 1756), 2027-2032.
  More info

  Abstract: A common proper-motion survey of M dwarf stars within 8 pc of the Sun reveals no new stellar or brown dwarf companions at wide separations (∼100-1400 AU). This survey tests whether the brown dwarf "desert" extends to large separations around M dwarf stars and further explores the census of the solar neighborhood. The sample includes 66 stars north of -30° and within 8 pc of the Sun. Existing first-epoch images are compared with new J-band images of the same fields an average of 7 yr later to reveal proper-motion companions within a ∼4′ radius of the primary star. No new companions are detected to a J-band limiting magnitude of ∼16.5, corresponding to a companion mass of ∼40 Jupiter masses for an assumed age of 5 Gyr at the mean distance of the objects in the survey, 5.8 pc.
• Benedict, G. F., McArthur, B. E., Franz, O. G., Wasserman, L. H., Henry, T. J., Takato, T., Strateva, I. V., Crawford, J. L., Ianna, P. A., McCarthy, D. W., Nelan, E., Jefferys, W. H., Altena, W. V., Shelus, P. J., Hemenway, P. D., Duncombe, R. L., Story, D., Whipple, A. L., Bradley, A. J., & Fredrick, L. W. (2001). Precise masses for wolf 1062 AB from hubble space telescope interferometric astrometry and Mcdonald observatory radial velocities. Astronomical Journal, 121(3), 1607-1613.
  More info

  Abstract: We present an analysis of astrometric data from Fine Guidance Sensor 3 (FGS 3), a white-light inter& ferometer on HST, and of radial velocity data from two ground-based campaigns. We model the astro& metric and radial velocity measurements simultaneously to obtain parallax, proper motion, and component masses for Wolf 1062 (G1 748; M3.5 V). To derive the mass fraction, we relate FGS 3 fringe scanning observations of the science target to a reference frame provided by fringe tracking observations of a surrounding star field. We obtain an absolute parallax (πabs = 98.0 ± 0.4 mas) yielding MA = 0.379 ± 0.005 M⊙ and MB = 0.192 ± 0.003 M⊙, high-quality component masses with errors of only 1.5%.
• Hall, P. B., Sawicki, M., Martini, P., Finn, R. A., Pritchet, C. J., Osmer, P. S., McCarthy, D. W., Evans, A. S., Lin, H., & Hartwick, F. D. (2001). Galaxies in the fields of z ∼ 1.5 radio-loud quasars. Astronomical Journal, 121(4), 1840-1862.
  More info

  Abstract: We have previously identified an excess population of predominantly red galaxies around a sample of 31 radio-loud quasars (RLQs) at 1 < z < 2. Here we show that these fields have a surface density of extremely red objects (EROs, with R - K > 6) 2.7 times higher than the general field. Assuming these EROs are passively evolved galaxies at the quasar redshifts, they have characteristic luminosities of only ∼ L*. Only one of four RLQ fields has an excess of J - K-selected EROs with J - K > 2.5; thus, those objects are mostly unrelated to the quasars. We also present new multiwavelength data and analyses on the fields of four of these quasars at zq ∼ 1.54, obtained to build more detailed pictures of the environments of these quasars and the galaxies within them. First, wide-field J and Ks data show that the galaxy excess around Q0835 + 580 is of Abell richness 2 ± 1 and extends to 140″ and that the galaxy excess around Q1126 + 101 extends to only 50″, even though the overall counts in the field are higher than the literature average. Second, in three fields we present the deepest narrowband redshifted Hα observations yet published. We detect five candidate galaxies at the quasar redshifts, a surface density 2.5 times higher than in the only existing random-field survey of similar depth. However, photometric spectral energy distribution (SED) fitting of one candidate suggests that it is an [O III] detection background to the quasar. Third, SCUBA submillimeter observations of three fields detect two of the quasars and two galaxies with SEDs best fitted as highly reddened galaxies at the quasar redshifts. Fourth, H-band adaptive optics (AO) imaging is used to estimate redshifts for two moderately red bulge-dominated galaxies in the Q0835 + 580 field using the Kormendy relation between central surface brightness and half-light radius. Both have structural redshifts consistent with early-type galaxies foreground to the quasar at z ≲ 0.2 or 1 ≲ z ≲ 1.35. Photometric redshifts do not confirm these structural redshifts, however, possibly because our optical photometry for these objects is corrupted by scattered light from the nearby bright AO guide star. Finally, quantitative SED fits are presented for numerous galaxies of interest in two fields and are used to constrain their photometric redshifts, zph. Most galaxies in the spatially compact group around Q0835 + 580 are consistent with being at the quasar redshift zq. One of these is a candidate very old galaxy without ongoing star formation, while the others appear to have ongoing or recent star formation. Many very and extremely red objects across both fields have zph ≃ zq, and significant dust is required to fit most of them, including about half of the objects whose fits also require relatively old stellar populations. Large reddenings of E(B - V) ≃ 0.6 ± 0.3 are also required to fit four J - K-selected EROs in the Q1126 + 101 field, though all but one of them have best-fit redshifts zph > zq. These objects may represent a population of dusty high-redshift galaxies underrepresented in optically selected samples. Taken together, these observations reinforce the claim that radio-loud quasars at zq > 1 can be found in galaxy overdensities. Ongoing star formation with moderate amounts of dust seems to be common among all but the very reddest galaxies in these overdensities.
• McCarthy Jr., D. W., Ge, J., Hinz, J. L., Finn, R. A., & Jong, R. D. (2001). PISCES: A wide-field, 1-2.5 μm camera for large-aperture telescopes. Publications of the Astronomical Society of the Pacific, 113(781), 353-361.
  More info

  Abstract: Wide-field-of-view infrared cameras, operating on the new generation of large telescopes, offer unprecedented gains in the detection of faint sources and in observing efficiency for both direct imaging and spectroscopy. With a 1024 × 1024 pixel, 1-2.5 μm detector, the PISCES camera provides 8′.5 and 3′.16 fields at the 2.3 m Bok telescope and 6.5 m Multiple Mirror Telescope, respectively. Its refractive optics utilize all spherical surfaces and standard glasses. A cold pupil stop suppresses the thermal background produced by the emissive surfaces normally present in Cassegrain optical configurations. The optical design is directly extendable to wider fields with larger detector formats. Future upgrades include low-resolution (R = 200-500) multiobject spectroscopy.
• Sarlot, R. J., & McCarthy, D. W. (2001). A cryogenic, 1-5 micron atmospheric dispersion corrector for astronomical adaptive optics. Proceedings of SPIE - The International Society for Optical Engineering, 4441, 72-78.
  More info

  Abstract: A cryogenic mechanism has been built to correct for the blurring effects of atmospheric dispersion in adaptive-optics images from large aperture telescopes. Steward Observatory's 6.5 m telescope features a deformable Cassegrain secondary mirror compensating for atmospheric turbulence at wavelengths from 1-5 microns. At 1 micron, smearing caused by atmospheric dispersion equals the diffraction-limited image width (0.04 arcseconds FWHM). In order to correct for this effect and to maintain the low thermal background provided by the adaptive secondary, we have designed and built a cryogenic (77 K) atmospheric dispersion corrector. Operating over a spectral range of 1-5 microns, two pairs of counter-rotating calcium/lithium-fluoride prisms provide diffraction-limited imaging over a field of 1.7 arcminutes at a zenith angle up to 45 degrees.
• Finn, R. A., & McCarthy, D. W. (2000). Multi-object, near-IR grism spectroscopy with the 6.5m MMT. Proceedings of SPIE - The International Society for Optical Engineering, 4008, II/-.
  More info

  Abstract: Wide-field infrared cameras, operating on the new generation of large telescopes, offer unprecedented gains in the detection of faint sources and in observing efficiency for both direct imaging and spectroscopy. PISCES, a near-IR (1-2.5 micron) wide-field camera designed for the f/9 secondaries of the Steward 2.3m and 6.5m MMT, is one such instrument that has been operational for over one year. Equipped with a 1024×1024 HAWAII HgCdTe array, PISCES offers an 8.5 arcminute field at the 2.3m and a 3.1 arcminute field at the MMT. Here we present our design to upgrade PISCES with a low resolution (R=200-500) grism for single and multi-object spectroscopy. The design allows J, H, and K-band spectroscopy in orders 5, 4 and 3, respectively. The combination of 6.5m aperture and multi-object capability will make PISCES a powerful tool for extending our knowledge of the low-mass regime of the initial mass function as well as star-formation in 0.5 < z < 1 galaxy clusters. We discuss design and fabrication issues and simulate the performance of the grism systems.
• McCarthy, D. W., Sabatke, E., Sarlot, R., Hinz, P., & Burge, J. (2000). Cryogenic beam-combiner for very low background, 2-20 micron interferometry on the 22.8 m Large Binocular Telescope. Proceedings of SPIE - The International Society for Optical Engineering, 4006, II/-.
  More info

  Abstract: The 22.8 m Large Binocular Telescope Interferometer will be a uniquely powerful tool for imaging and nulling interferometry at thermal infrared wavelengths (2-20 μm) because of the LBT's unusual combination of low emissivity, high spatial resolution, broad (u,v)-plane coverage, and high photometric sensitivity. The Gregorian adaptive secondary mirrors permit beam combination after only three warm reflections. They also control the relative pathlength, wavefront tip/tilt, and focus of the two telescope beams, thus greatly simplifying the complexity of the beam-combiner. The resulting four-mirror beam-combiner reimages the original focal plane and also images the telescope pupil onto a cold stop to limit thermal background. At first-light in 2004, an all-reflective, cooled beam-combiner can provide a 2 arcmin diameter field for Fizeau-style imaging as well as the low thermal background and achromaticity required for nulling interferometry. In designing the optics of such a beam-combiner, we can maximize the field of view at the combined focus by balancing the competing effects of differential phase, tilt, distortion, focus, and pupil matching. To achieve a `peak Strehl' of 0.9 at a wavelength of 4.8 μm across a 1.0 arcmin field radius, strong constraints are placed on differential image overlap (approximately 0.03 arcsec), single beam distortion (0.1%), and pupil matching (0.1%). This cryogenic beam-combiner can feed a variety of interchangeable cameras and spectrographs. Tip/tilt and pathlength (phase) sensors near the final focus within each science instrument will control the adaptive secondaries to maintain precise alignment and provide the highest possible Strehl ratio.
• Henry, T. J., Franz, O. G., Wasserman, L. H., Benedict, G. F., Shelus, P. J., Ianna, P. A., Kirkpatrick, J. D., & McCarthy Jr., D. W. (1999). The optical mass-luminosity relation at the end of the main sequence (0.08-0.20 M_⊙). Astrophysical Journal Letters, 512(2 PART 1), 864-873.
  More info

  Abstract: The empirical mass-luminosity relation at Mv is presented for stars with masses 0.08-0.20 M⊙ based upon new observations made with Fine Guidance Sensor 3 on the Hubble Space Telescope. The targets are nearby, red dwarf multiple systems in which the magnitude differences are typically measured to ±0.1 mag or better. The Mv values are generated using the best available parallaxes and are also accurate to ±0.1 mag, because the errors in the magnitude differences are the dominant error source. In several cases this is the first time the observed sub-arcsecond multiples have been resolved at optical wavelengths. The mass-luminosity relation defined by these data reaches to Mv = 18.5 and provides a powerful empirical test for discriminating the lowest mass stars from high-mass brown dwarfs at wavelengths shorter than 1 μm.
• Sarlot, R. J., McCarthy, D. W., Burge, J. H., & Jian, G. e. (1999). Optical design of ARIES: The new near infrared science instrument for the adaptive f/15 Multiple Mirror Telescope. Proceedings of SPIE - The International Society for Optical Engineering, 3779, 274-283.
  More info

  Abstract: Steward Observatory is building a deformable f/15 secondary mirror that will compensate for atmospheric turbulence for the 6.5 m Multiple Mirror Telescope conversion. With the proposed adaptive optics system, this new telescope is expected to resolve diffraction limited images (greater than 80% Strehl ratio at 2.2 μm), approximately an order of magnitude better than present seeing. This improved visibility with a larger light collecting area and low thermal background requires a new science instrument, diffraction limited for the 1 to 5 μm region. This science instrument, presently in its early manufacturing stages, consists of four cameras (optimized for plate scales from 0.019 arcsec/pixel to 0.102 arcsec/pixel), low resolution spectroscopy with grisms (λ/Δλ from 250 to 500), high resolution spectroscopy with a cross-dispersed Echelle grating (λ/Δλ from 3,000 to 60,000) and an atmospheric dispersion corrector. The cameras will provide simultaneous slit viewing, differential imaging and two pixel sampling over the full wavelength band. Each camera will operate with a 1024×1024 HgCdTe array optimized for the spectral region of the camera. An infrared tip/tilt sensor is also incorporated into the instrument that will relay natural guide star motion to the adaptive secondary in a closed-loop approach. This paper is an optical design instrument overview.
• Franz, O. G., Henry, T. J., Wasserman, L. H., Benedict, G. F., Ianna, P. A., Kirkpatrick, J. D., McCarthy Jr., D. W., Bradley, A. J., Duncombe, R. L., Fredrick, L. W., Hemenway, P. D., Jefferys, W. H., McArthur, B. E., Nelan, E. P., Shelus, P. J., Story, D. B., F., W., & Whipple, A. L. (1998). The first definitive binary orbit determined with the Hubble Space Telescope fine guidance sensors: Wolf 1062 (Gliese 748). Astronomical Journal, 116(3), 1432-1439.
  More info

  Abstract: The M dwarf binary, Wolf 1062 (Gliese 748), has been observed with the Hubble Space Telescope (HST) Fine Guidance Sensor 3 in the transfer function scan mode to determine the apparent orbit. This is the first orbit defined fully and exclusively with HST, and is the most accurate definitive orbit for any resolved, noneclipsing system. The orbital period is 2.4490 ± 0.0119 yr and the semimajor axis is 0″.1470 ± 0″.0007 - both quantities are now known to better than 1%. Using the weighted mean of seven parallax measurements and these HST data, we find the system mass to be 0.543 ± 0.031 M⊙, where the error of 6% is due almost entirely to the parallax error. An estimated fractional mass from the infrared brightness ratio and infrared mass-luminosity relation yields a mass for the primary of 0.37 M⊙, and the secondary falls in the regime of very low mass stars, with a mass of only 0.17 M⊙.
• Langlois, M. P., Sandler, D. G., Ryan, P. T., & McCarthy Jr., D. W. (1998). High-frequency wavefront structure and its effects on the detection of faint companions using adaptive optics. Proceedings of SPIE - The International Society for Optical Engineering, 3353, 189-200.
  More info

  Abstract: This paper looks at the detection limits using the new adaptive optics system on the 3.5m SOR telescope, reported by P. Ryan et al. at this conference. We discuss recent advances in our understating of the nature of high frequency wavefront structure. We analyze the various sources of high- frequency wavefront error, arising from residual adaptive optics errors, and other sources of scattered light. We characterize the AO system efficiency in the K band in terms of profile, noise level and noise time correlation. A sharp edge coronograph was used and it improved the performance as much as needed to detect brown dwarfs. Finally we give the exposure time required to detect such companions using the actual AO associated with the coronographic device, and we also point out what needs to be improved on the AO system as well as on the coronographic device in order to reach the level required for detecting exoplanets. ©2003 Copyright SPIE - The International Society for Optical Engineering.
• Ghez, A. M., Mccarthy, D. W., Patience, J. L., & Beck, T. L. (1997). The multiplicity of pre-main-sequence stars in southern star-forming regions. Astrophysical Journal Letters, 481(1 PART I), 378-385.
  More info

  Abstract: High-resolution studies of young stars in the star-forming regions of Taurus and Ophiuchus have revealed a large population of multiple star systems. To test how applicable this earlier result is for other star-forming regions, we have carried out a K-band (2.2 μm) multiplicity survey of pre-main-sequence stars located in the dark cloud complexes Chameleon, Lupus, and Corona Australis. This survey, which was conducted with both speckle- and direct-imaging techniques, covers a binary star separation range of 0″.1-12″ (15-1800 AU) and identifies 25 companion stars of which nine are new detections. The companion star fraction over the separation range covered by this survey is estimated to be 0.52 ± 0.11, in agreement with Taurus (0.58 ± 0.08) and Ophiuchus (0.50 ±0.12). A comparison of the direct-imaging portion of this survey with Reipurth & Zinnecker's optical multiplicity study reveals that 4% of the overlap sample have "infrared companions," companions too red to be detected at optical wavelengths. This suggests that infrared surveys will systematically measure a slightly higher companion star fraction compared with optical surveys. The result of combining all K-band surveys of dark cloud complexes, which cover the separation range 15-1800 AU, shows a factor of 2 excess of the companion star fraction for young stars compared with that for the solar-type stars in the solar neighborhood (0.54 ± 0.06 vs. 0.26 ± 0.04). © 1997. The American Astronomical Society. All rights reserved.
• Leinert, C., Henry, T., Glindemann, A., & McCarthy Jr., D. W. (1997). A search for companions to nearby southern M dwarfs with near-infrared speckle interferometry. Astronomy and Astrophysics, 325(1), 159-166.
  More info

  Abstract: We searched the 9 M-dwarf primaries nearer than 5 pc and south of declination δ = -30° for companions with separations 1-10 AU and found none. Taken together with the 25 northern primaries studied by Henry and McCarthy (1990) the fraction of binaries and triples within the now complete sample of all M dwarfs within 5 pc is 9/34 = 26 ± 9%, and the average number of companions per system is 0.32 ± 0.10. This is lower by 2σ than the observed multiplicity fraction of 43 ± 5%, and companions per system of 0.49 ± 0.05 in the sample of nearby solar-type main sequence stars. It is also much lower than the extrapolated binary fraction among young stars in Taurus. We discuss the implications of this finding.
• McCarthy, D., Stolovy, S., Kern, S., Schneider, G., Ferro, A., Spinrad, H., Black, J., & Smith, B. (1997). NICMOS/HST post-perihelion images of comet Hale-Bopp in outburst. Earth, Moon and Planets, 78(1-3), 243-249.
  More info

  Abstract: Near-infrared images of comet Hale-Bopp (C/1995 O1) were obtained from NICMOS/HST on UT August 27-28, 1997, when the comet emerged from the 50 degree solar elongation limit at 2.99 AU from Earth. Diffraction-limited images were obtained with camera 2 filters centered at 1.87, 1.90, 2.04 and 2.22 μm with ~0.2″ resolution (0.076″/pixel; 165 km/pixel). Over the 1.7-hour baseline of observation, a recent (
• Mutz, S. B., Windhorst, R. A., Wittman, D., Close, L. M., & McCarthy Jr., D. W. (1997). High-resolution V, I, and K-band imaging of faint field galaxies from the HST medium-deep survey. Astronomical Journal, 113(5), 1537-1547.
  More info

  Abstract: We present infrared and optical data for 13 galaxies with 16.0 ≤ I ≤ 21 mag previously observed with the Hubble Space Telescope as part of a study of 300 galaxies from the Medium-Deep Survey. We observed four of these galaxies at the Steward Observatory 90″ and 61″ telescopes in the K band (λeff = 2.2 μm) with a tip-tilt secondary mirror system (FASTTRAC) designed to give high-resolution infrared images. During nights of good seeing at the 61″ telescope, we were able to derive K-band images with FWHM = 0″.8 for a stack of 158 1-min images. We present V, I, and K-band light profiles for these galaxies at 0″.2.-1″.0 resolution, as well as their optical and infrared photometry and their (V - I) and (V - K) color gradients. The relatively flat color gradients of these galaxies indicate that little or no spectral evolution has occurred since z ∼ 0.8, consistent with previous studies of their scale lengths through the θ-z relation. The majority of this small sample exhibits evidence of significant reddening. The reddening is most likely due to dust, both in the line of sight and in some cases, internal to the galaxies. © 1997 American Astronomical Society.
• Close, L. M., Brusa, G., Bruns, D. G., Lloyd-Hart, M., & McCarthy Jr., D. W. (1995). Adaptive beam-combining mirror for the MMT. Proceedings of SPIE - The International Society for Optical Engineering, 2534, 105-115.
  More info

  Abstract: We present a novel, high performance, and economical design for tip-tilt mirrors. The two- dimensional tilt of each mirror is sensed through capacitive displacement sensors sensitive to approximately 1 nm rms out to 10 KHz. An analogue PID circuit utilizes this positional feedback to lock the mirrors to the commanded tilt via voice coil drivers. These mirrors achieve a 10 - 90% risetime of 3.0 ms and have a critically damped response at 100 - 150 Hz update rates. We have incorporated six of these tip-tilt mirrors to adaptively combine all six beams from the MMT. During first light of the instrument in April 1995, individual beams improved from 1.1 inch to 0.6 inch FWHM in 60 s exposures corrected with 60 Hz update rates.
• Close, L. M., Mccarthy Jr., D. W., & Melia, F. (1995). Infrared photometry of the black hole candidate Sagittarius A. Astrophysical Journal Letters, 439(2), 682-686.
  More info

  Abstract: An infrared source has been imaged within 0″.2 ± 0″.3 of the unique Galactic center radio source Sgr A*. High angular resolution (〈FWHM〉 ∼ 0″.55) was achieved by rapid (∼50 Hz) real-time image motion compensation. The source's near-infrared magnitudes (K = 12.1 ± 0.3, H = 13.7 ± 0.3, and J = 16.6 ± 0.4) are consistent with a hot object reddened by the local extinction (Av ∼ 27). At the 3 σ level of confidence, a time series of 80 images limits the source variability to less than 50% on timescales from 3 to 30 minutes. The photometry is consistent with the emission from a simple accretion disk model for a ∼1 × 106 M⊙ black hole. However, the fluxes are also consistent with a hot luminous (L ∼ 103.5-4.6 L⊙) central cluster star positionally coincident with Sgr A*.
• Ghez, A. M., Weinberger, A. J., Neugebauer, G., Matthews, K., & Mccarthy Jr., D. W. (1995). Speckle imaging measurements of the relative tangential velocities of the components of T Tauri binary stars. Astronomical Journal, 110(2), 753-765.
  More info

  Abstract: Over a five year period, we have used speckle imaging to monitor 20 T Tauri binary stars with separations ranging from 0″.09 to 1″ (13-140 AU). This project is aimed at detecting the relative motion of the component stars to ascertain whether or not the observed companions (1) are stellar in nature, as opposed to being HH objects, and (2) are gravitationally bound to the primary stars. These observations demonstrate that speckle imaging measurements of close binary stars' separations can be made with an accuracy of a few milliarcseconds. The majority of the observed systems show significant relative velocities which (1) are not consistent with the motion expected for HH objects, (2) are greater than the velocity dispersion of these star-forming regions and thus are not the result of differential proper motion, and (3) are consistent with orbital motion. This is the first demonstration that these systems are physically bound. Furthermore, these relative velocity measurements provide dynamical evidence that the average total mass of these T Tauri binary star systems is ∼1.7Script M sign0. © 1995 American Astronomical Society.
• Hollywood, J. M., Melia, F., Close, L. M., Mccarthy Jr., D. W., & Dekeyser, T. A. (1995). General relativistic flux modulations in the Galactic center black hole candidate sagittarius A. Astrophysical Journal Letters, 448(1 PART 2), L21-L24.
  More info

  Abstract: The proximity of the unique radio source Sgr A * at the Galactic center is allowing us to make unprecedented observations of the spectral formation region near the event horizon of a massive black hole. Near-infrared flux measurements hint at a possible 10.4 minute modulation period in this source, which suggests an emission surface with a Keplerian velocity near the last stable orbit of a 106 M⊙ Schwarzschild object. In this Letter, we set up the fully general relativistic framework for calculating such modulations, which we suggest might arise from orbiting disk inhomogeneities. The application of our method to the currently available data shows excellent agreement between the calculated light curve and the observed temporal profile, promising exciting future observations of Sgr A * with NICMOS on Hubble Space Telescope.
• Jura, M., Ghez, A. M., White, R. J., Mccarthy, D. W., Smith, R. C., & Martin, P. G. (1995). The fate of the solid matter orbiting HR 4796A. Astrophysical Journal Letters, 445(1), 451-456.
  More info

  Abstract: We have obtained optical spectra, 2 μm speckle images, and an upper limit to the 800 μm flux for HR 4796A, and optical spectra for its physical companion separated by 7″.7, HR 4796B. We detect Hβ, Hγ, and the calcium H and K lines in emission from HR 4796B; these data are consistent with the hypothesis that it is later than spectral type M2 and lies substantially above the main-sequence. From the location of HR 4796B on the H-R diagram, the estimated age of this star is 3 × 106 yr, and assuming this age for the entire system, we find from our 2 μm speckle data that there is no close stellar companion to HR 4796A (M > 0.125 M⊙) between 11 and 120 AU from the star. From the IRAS and ground-based photometry, it seems that there is a hole in the dust distribution around HR 4796A with an inner radius of between ∼40 and ∼200 AU. The observed circumstellar dust grains, which lie at D > 40 AU from the star, are likely to be at least 3 μm in radius in order to be gravitationally bound to HR 4796A, if the circumstellar dust cloud is optically thin. Since they are larger than almost all interstellar grains, the circumstellar dust grains probably grew by coalescence. Because the existing grains at D > 40 AU have undergone measurable coalescence, it is possible that particles that presumably once existed at D < 40 AU, where the collision times were shorter than at D > 40 AU, grew into macroscopic objects. A likely explanation for the dust hole is that there is a companion located at about half the inner radius of the dust hole, or between 20 and 100 AU from the star. If such a companion exists, it must have a mass less than 0.125 M⊙. Since grain coalescence has occurred, this putative companion possibly could be a planet.
• Close, L. M., Wittman, D. M., & McCarthy Jr., D. W. (1994). High-resolution infrared imaging utilizing a tip-tilt secondary mirror. Proceedings of SPIE - The International Society for Optical Engineering, 2201, 447-457.
  More info

  Abstract: A tip-tilt secondary system has been developed on a 2.3 m telescope. The system, called FASTTRAC, stabilizes image motion to less than 0.1' rms at closed loop corrective frequencies of ≤ 100 Hz. Resolutions of 0.19' and Strehl ratios of 0.14 have been obtained in long exposure images at 1.6 μm in seeing conditions of D/ro approximately 4. FASTTRAC is unique in its ability to use infrared guide stars (K ≤ 8). Recently FASTTRAC was upgraded to accommodate a low read noise CCD, allowing faint visible guide stars to be utilized. We anticipate that guide stars of R = 17 will be adequate at correction frequencies of 30 Hz.
• Coppenbarger, D. S., Henry, T. J., & McCarthy Jr., D. W. (1994). Ross 614AB: A redetermination of the masses one orbit later. Astronomical Journal, 107(4), 1551-1555.
  More info

  Abstract: Accurate masses are reported for the components of the nearby binary Ross 614 AB by supplementing visual and photographic measurements with 1D and 2D infrared speckle data taken during the last seven years. The new data presented here, in conjunction with all available previous resolved observations of the system, yield larger masses for the components, 0.179±0.047 and 0.083±0.023script M sign⊙, than previously reported. Both components are among the handful of systems with masses determined to be ≤0.2.script M sign⊙, and provide important calibration points for the lower main sequence.
• Ghez, A. M., Mccarthy Jr., D. W., Weinberger, A. J., Neugebauer, G., & Matthews, K. (1994). A near infrared speckle imaging study of T Tauri Stars - Orbital motion. Experimental Astronomy, 3(1-4), 297-300.
  More info

  Abstract: The results of a speckle imaging survey of T Tauri stars suggest that most, if not all, young low mass stars have companions. Repeated observations of these young binary stars have revealed orbital motion in the closest pairs (≤0.″3), proving that these systems are indeed gravitationally bound and providing the basis for mass estimates in the upcoming years. These mass estimates are necessary to distinguish between the various binary star formation mechanisms that have been proposed to date. © 1994 Kluwer Academic Publishers.
• Kirkpatrick, J. D., & Mccarthy Jr., D. W. (1994). Low mass companions to nearby stars: Spectral classification and its relation to the stellar/substellar break. Astronomical Journal, 107(1), 333-349.
  More info

  Abstract: The relationship between mass and spectral class for main-sequence stars has never been obtained for dwarfs cooler than M6; currently, the true nature of objects classified as M7, M8, M9, or later (be they stellar or substellar) is not known. In this paper, spectral types for the components in five low mass binary systems are estimated based on previously published infrared speckle measurements, red/ infrared photometry, and parallax data, together with newly acquired high signal-to-noise composite spectra of the systems and revised magnitude difference relations for M dwarfs. For two of these binaries, the secondary has a smaller mass (< 0.09 script M sign⊙) than any object having a dynamically measured mass and a known spectral type, thus extending the spectral class/mass relation to lower masses than has previously been possible. Data from the higher mass components (0.09script M sign⊙≤script M sign≤0.40script M sign⊙) are consistent with earlier results; the two lowest mass objects - though having mass errors which could place them on either side of the M dwarf/brown dwarf dividing line (script M sign ≈0.08script M sign⊙) - are found to have spectral types no cooler than M6.5 V. An extrapolation of the updated spectral class/mass relation to the hydrogen-burning limit suggests that objects of type M7 and later may be substellar. Direct confirmation of this awaits the discovery of a close, very late-type binary for which dynamical masses can be measured.
• Klrkpatrick, J. D., McGraw, J. T., Hess, T. R., Liebert, J., & McCarthy Jr., D. W. (1994). The luminosity function at the end of the main sequence: Results of a deep, large-area, CCD survey for cool dwarfs. Astrophysical Journal, Supplement Series, 94(2), 749-788.
  More info

  Abstract: The luminosity function at the end of the main sequence is determined from V, R, and I data taken by the CCD/Transit Instrument, a dedicated telescope surveying an 8prime;.25 wide strip of sky centered at δ = + 28°, thus sampling Galactic latitudes of + 90° down to - 35°. A selection of 133 objects chosen via R - I and V - I colors has been observed spectroscopically at the 4.5 m Multiple Mirror Telescope to assess contributions by giants and subdwarfs and to verify that the reddest targets are objects of extremely late spectral class. Eighteen dwarfs of type M6 or later have been discovered, with the latest being of type M8.5. Data used for the determination of the luminosity function cover 27.3 deg2 down to a completeness limit of R = 19.0. This luminosity function, computed a V, I, and bolometric magnitudes, shows an increase at the lowest luminosities, corresponding to spectral types later than M6 - an effect suggested in earlier work by Reid & Gilmore and Leggett & Hawkins. When the luminosity function is segregated into north Galactic and south Galactic portions, it is found that the upturn at faint magnitudes exists only in the southern sample. In fact, no dwarfs with MI ≥ 12.0 are found within the limiting volume of the 19.4 deg2 northern sample, in stark contrast to the smaller 7.9 deg2 area at southerly latitudes where seven such dwarfs are found. This fact, combined with the fact that the Sun is located ∼ 10-40 pc north of the midplane, suggests that the latest dwarfs are part of a young population with a scale height much smaller than the 350 pc value generally adopted for other M dwarfs. These objects comprise a young population either because the lower metallicities prevalent at earlier epochs inhibited the formation of late M dwarfs or because the older counterparts of this population have cooled beyond current detection limits. The latter scenario would hold if these late-type M dwarfs are substellar. The luminosity function data together with an empirical derivation of the mass-luminosity relation (from Henry & McCarthy) are used to compute a mass function independent of theory. This mass function increases toward the end of the main sequence, but the observed density of M dwarfs is still insufficient to account for the missing mass. If the increases seen in the luminosity and mass functions are indicative of a large, unseen, substellar population, brown dwarfs may yet add significantly to the mass of the Galaxy.
• McCarthy Jr., D. W., Freeman, J. D., & Drummond, J. D. (1994). High Resolution Images of Vesta at 1.65 μm. Icarus, 108(2), 285-297.
  More info

  Abstract: A series of high spatial resolution (∼140 km) images of the asteroid 4 Vesta has been obtained in reflected light at 1.65 μm during the solar oppositions of 1990 and 1992. Full longitudinal coverage has provided a solution for the triaxial dimensions and rotational pole orientation. Although resolvable surface features are indicated from other techniques, they are not imaged here and must have low contrast relative to the overall background of reflected light. However, in all 48 images, a nonmoving "spot," a possible glint(s), does appear near the sub-Sun point contributing ∼10-18% of the total flux. This feature does not appear in similar observations of the asteroid 1 Ceres. © 1994 Academic Press. All rights reserved.
• Henry, T. J., & Mccarthy Jr., D. W. (1993). The mass-luminosity relation for stars of mass 1.0 to 0.08script M sign_⊙. Astronomical Journal, 106(2), 773-789.
  More info

  Abstract: Mass-luminosity relations determined at infrared wavelengths are presented for stars with masses 1.0 to 0.08script M sign⊙. Using infrared speckle imaging techniques on a sample of nearby binaries, we have been able to concentrate on the lower main sequence (script M sign≤0.5script M sign⊙), for which an accurate mass-luminosity calibration has remained problematic. In addition, the mass-visual luminosity relation for stars with 20≥scriptMsign≥0.08script M sign⊙ is produced by implementing new photometric relations linking V to JHK wavelengths for the nearby stars, supplemented with eclipsing binary information. These relations predict that objects with masses ∼0.08script M sign⊙ have MK∼10 and MV∼18.
• Mccarthy Jr., D., Hancock, T., Freeman, J., McLeod, B., Lloyd-Hart, M., Colucci, D., Wizinowich, P., Clampin, M., Golimowski, D., & Durrance, S. (1993). Infrared imaging of M Cas B using rapid image motion compensation. Astronomical Journal, 105(2), 652-659.
  More info

  Abstract: The orbital parameters and component masses of the μ Cas binary system can provide a measure of the helium abundance in the early Galaxy. In a continuing effort to measure these characteristics, we have obtained the first direct images of the low mass companion to μ Cas A using techniques for high speed correction of image motion at 1.25 and 1.65 μm. These techniques include real-time tracking of the brightest infrared speckle at 75 Hz and of the visible centroid at 500 Hz. Mu Cas B is easily detected with a magnitude difference relative to the primary of > 4 at a separation of ∼1.4 arcsec. Its energy distribution from 0.55 to 3.4 μm yields an effective temperature (3034±160 K), stellar diameter (0.26 R⊙), and luminosity (0.0051±0.0011 L⊙). A direct mass measurement using two photocentric orbits yields 0.15±0.0013 script M⊙. Significant improvements in these parameters can result from astrometric, spectroscopic, and imaging observations of the upcoming periastron passage.
• Henry, T. J., Mccarthy Jr., D. W., Freeman, J., & Christou, J. C. (1992). Nearby solar-type star with a low-mass companion: New sensitivity limits reached using speckle imaging. Astronomical Journal, 103(4), 1369-1373.
  More info

  Abstract: We have imaged the low-mass companion to the nearby solar-type star Gliese 67 using two-dimensional infrared speckle imaging techniques. The binary has been resolved at J (1.25 μm), H (1.65 μm), and K (2.2 μm), allowing us to determine the magnitudes and colors of the components. In observations spanning 14 months, the secondary has been found at separations and position angles predicted by the astrometric orbit, and we calculate the component masses to be 0.97 and 0.29 script M sign⊙. With a magnitude difference of 4.5 mag at K, these observations define a new sensitivity limit for companions at subarcsecond scales, 6-9 AU for the observations reported here of the Gliese 67 system. For the G dwarf/M dwarf pair, this brightness ratio corresponds to 7.5 mag at V, or a flux ratio of 1000. The data indicate that even greater sensitivity is possible, to companions six magnitudes fainter than their primaries in the infrared, thereby allowing us to search for very low-mass secondaries (∼0.1 script M sign⊙) orbiting nearby solar-type stars.
• Kirkpatrick, J. D., Henry, T. J., & Mccarthy Jr., D. W. (1991). A standard stellar spectral sequence in the red/near-infrared: Classes K5 to M9. Astrophysical Journal, Supplement Series, 77(3), 417-440.
  More info

  Abstract: Spectra of 39 K and M dwarf spectroscopic standards, as well as 38 secondary standards, are shown from 6300 to 9000 Å. This sequence of 77 spectra ranges from K5 V to M9 and has been classified on the Boeshaar system. Spectra of 14 giant and higher luminosity stars are presented from 6900 to 9000 Å, along with two miscellaneous spectra. Also given is an extensive list of atomic and molecular features found in the spectra of late K and M stars of all luminosity classes. From the spectral slopes and the strengths of the red/near-infrared spectral features it is possible to distinguish giants from dwarfs and to classify M dwarfs of all spectral subclasses. The library of spectra has been used to construct a spectral class versus mass relation which allows mass estimates to be made based upon a dwarf's spectral class alone. The relation is based on eight objects having both well-determined masses and spectral types.
• McCarthy Jr., D. W., Henry, T. J., McLeod, B., & Christou, J. C. (1991). The low-mass companion of gliese 22A: First results of the steward observatory infrared speckle camera. Astronomical Journal, 101(1), 214-219.
  More info

  Abstract: Two-dimensional infrared imaging of the double star Gliese 22AB at H (1.6 μm) and K (2.2 μm) has directly detected the low-mass, astrometric component Gliese 22C. The M dwarf primary, GL 22A, was reported to be an astrometric binary by Hershey (1973); we provide the first image of the astrometric companion, at a separation of 0.5″, and determine the masses of GL 22AC to be 0.36 and 0.12 Script M sign⊙. From its infrared flux, GL 22B is estimated to have a mass of 0.18 Script M sign⊙. The system is now known to contain a primary orbited by two similar secondaries in what appear to be nearly coplanar, circular, corevolving orbits at distances of 5 and 40 AU, similar to the scale and orbital mechanics of our solar system.
• Mcleod, B. A., Mccarthy Jr., D. W., & Freeman, J. D. (1991). Global high-resolution imaging of hotspots on Io. Astronomical Journal, 102(4), 1485-1489.
  More info

  Abstract: We present 3.8 μm images of the Jovian satellite Io at an unprecedented ground-based resolution of 0 18. The images were obtained through two-dimensional speckle interferometry using the 6.86 m aperture of the Multiple Mirror Telescope in November 1989 and March 1990. To process the images we developed new speckle reduction techniques appropriate for objects with a size that is a significant fraction of the field of view. The images show three volcanic hotspots, including Pele, detected here for the first time since the Voyager 1 flyby in 1979.
• Henry, T. J., & Mccarthy Jr., D. W. (1990). A systematic search for brown dwarfs orbiting nearby stars. Astrophysical Journal, 350(1), 334-347.
  More info

  Abstract: We have concluded a systematic search for brown dwarf and stellar companions to every known M dwarf star within 5 pc north of -30°. Using infrared speckle interferometry, we have examined a region 0″.2 to 5″ in radius around 27 stars at the infrared H (1.6 μm) and K (2.2 μm) bands, at which low-mass companions are expected to emit maximum radiation near their blackbody peaks. Two stars were found to have very low mass, previously unseen companions: G208-44, which is an astrometric binary, and GL 866. The five previously known close M dwarf binaries with well-determined masses and these two new M dwarf doubles, all with separations less than 3″, were observed at J (1.25 μm), H, and K in order to produce mass-luminosity relations at these wavelengths. All stellar and substellar objects to an MK of 11.5 and MH of 12.0 would have been detected around most of the target stars. For these infrared magnitudes, comparisons to the low-mass star and brown dwarf evolutionary models of D'Antona and Mazzitelli yield corresponding mass limits of 70 and 80 Jupiters at ages of 8 × 108 and 8 × 109 yr, which are representative ages for the sample. All astrometric companions of stars in the survey which remain undetected now have limits placed upon their infrared fluxes. We believe that all stellar companions to the survey objects have been discovered, and we find that the infrared luminosity function at the very red end of the main sequence is not falling but rising, until an abrupt cutoff corresponding to the stellar/substellar breakpoint at MK = 10.0. The census of M dwarfs within 5 pc north of -30° is now revised to include 19 single M dwarfs, eight M dwarf binaries, one M dwarf triple system, and one M dwarf in a triple system with earlier spectral type components. We have found no definite brown dwarf companions on the scale of our planetary system (2-10 AU) around any M dwarfs within 5 pc, and we are now extending the survey to 10 pc.
• McCarthy Jr., D. W., McLeod, B. A., & Barlow, D. (1990). Infrared array camera for interferometry with the cophased Multiple Mirror Telescope. Proceedings of SPIE - The International Society for Optical Engineering, 1237, 496-507.
  More info

  Abstract: An infrared camera has been developed for interferometric imaging on large telescopes. Observations obtained with the 6.86 m aperture of the cophased Multiple Mirror Telescope (MMT) demonstrate the ease with which future 8 m telescopes can achieve diffraction-limited performance from 1 to 5.5 μm. With the MMT, the infrared camera has imaged astronomical sources at 3.5 μm with a diffraction-limited resolution of 0.10 arcsec. The camera uses a 58×62 pixel InSb focal plane array built by Santa Barbara Research Center (SBRC) to obtain high quantum efficiency (approximately 80%) and low readout noise (300 electrons per picture). An excess noise from the SBRC detector is related to the resetting process and can be removed through proper readout methods and data processing. Interchangeable optics, filters, an internal focal plane shutter, and a coronagraphic mask are cooled inside the dewar to reduce the thermal background. Adjustable exposures as short as 4 msec are obtained at a maximum rate of 10 Hz to freeze atmospheric turbulence. A VMEbus, 68020-based computer system digitizes and records raw data, displays data frames in real-time, and computes the coadded power spectra and object visibilities.
• Cobb, M. L., & McCarthy Jr., D. W. (1986). COMPARATIVE STUDY OF DECONVOLUTION TECHNIQUES FOR INFRARED SPECKLE INTERFEROMETRY.. Proceedings of SPIE - The International Society for Optical Engineering, 627(pt 2), 758-765.
  More info

  Abstract: Three deconvolution techniques, CLEAN, Maximum Entropy Method (MEM) and L. B. Lucy's algorithm, are compared through both one-dimensional computer simulation and real astronomical data obtained at high angular resolution. These algorithms are evaluated according to speed, noise sensitivity, and resolution gain. For the simulations, we define the resolution gain needed to separate the components of an equal double as the ratio of the FWHM of the point spread function to the double separation. CLEAN is at least two orders of magnitude faster than the other two algorithms but is limited in usefulness to resolution gains near unity. Lucy's algorithm converges rapidly at first and achieves a resolution gain near two but requires smoothing techniques to reduce its sensitivity to noise. MEM is less sensitive to noise and is capable of resolution gains as high as four. These conclusions are also demonstrated with real astronomical data where MEM again produces the smoothest image consistent with the signal-to-noise.
• McCarthy Jr., D. W., & Cobb, M. L. (1986). APPLICATION OF IMAGE SHARPNESS CRITERIA IN INFRARED SPECKLE INTERFEROMETRY.. Proceedings of SPIE - The International Society for Optical Engineering, 627(pt 2), 797-804.
  More info

  Abstract: Current techniques for infrared speckle interferometry treat all exposures with equal weight regardless of instantaneous atmospheric 'seeing'. In an effort to improve accuracy in measurements of visibility amplitude and phase, we utilize measurements of image quality to bin individual exposures. We have investigated several criteria including the second-order moment of the image (an estimate of the Fried parameter) and two sharpness functions considered previously in adaptive optics applications. Test results on bright stars indicate that the sharpness parameters are more sensitive to image quality. These tests also delineate the correlation between sharpness and the second-order moment and demonstrate the variations, sometimes periodic, in image quality caused by atmospheric seeing. Initial tests of a binning technique using real astronomical data exhibit improved accuracy and reduced sensitivity to atmospheric fluctuations.
• Binder, A. B., & McCarthy Jr., D. W. (1972). Mars: The lineament systems. Science, 176(4032), 279-281.
  More info

  Abstract: Analysis of the Mariner 4, Mariner 6, and Mariner 7 photographs shows that Mars has at least two distinct types of lineament systems. The most prominent is a well-developed global-type system. The second consists of radial and concentric lineaments associated with the Hellas and south polar basins.

Proceedings Publications

• Buxner, S., Impey, C., Follette, K., Dokter, E., McCarthy, D., Vezino, B., Formanek, M., Romine, J., Brock, L., Neiberding, M., & Prather, E. (2017, jan). Results of Studying Astronomy Students\rsquo Science Literacy, Quantitative Literacy, and Information Literacy. In American Astronomical Society Meeting Abstracts, 229.
• Lebofsky, L., McCarthy, D., Wright, J., Wright, R., Mace, M., & Floyd, C. (2017, oct). An Inaugural Girl Scout Destinations Astronomy Camp. In AAS/Division for Planetary Sciences Meeting Abstracts \#49, 49.
• Ward-Duong, K. .., Patience, J., De, R. R., Bulger, J., Rajan, A., Goodwin, S., Parker, R., McCarthy, D., Kulesa, C., Plas, G., Menard, F., Pinte, C., Jackson, A., Bryden, G., Turner, N., Harvey, P., & Hales, A. (2017, jan). Companions and Environments of Low-Mass Stars: From Star-Forming Regions to the Field. In American Astronomical Society Meeting Abstracts, 229.
• Follette, K., McCarthy, D., Dokter, E., Buxner, S., & Prather, E. (2016, jan). Examining the Role of Numeracy in College STEM Courses: Results from the Quantitative Reasoning for College Science (QuaRCS) Assessment Instrument. In American Astronomical Society Meeting Abstracts, 227.
• Henry}, T., Jao, W., Winters, J., Dieterich, S., Finch, C., Hambly, N., Ianna, P., McCarthy, D., Riedel, A., Subasavage, J., & Team, {. (2016, jan). The Census of Objects within 10 Parsecs. In American Astronomical Society Meeting Abstracts, 227.
• Herman, M., Waaler, M., Patience, J., Ward-Duong, K. .., Rajan, A., McCarthy, D., Kulesa, C., & Wilson, P. (2016, jan). Adaptive Optics Imaging of Exoplanet Host Stars. In American Astronomical Society Meeting Abstracts, 227.
• Lebofsky}, L., McCarthy, D., DeVore, E., Harman, P., & Team, {. S. (2016, oct). Leadership Workshops for Adult Girl Scout Leaders. In AAS/Division for Planetary Sciences Meeting Abstracts, 48.
• {Lejoly}, C., {Mommert}, M., {Trilling}, D., {Pinilla-Alonso}, N., {Emery}, J., {Melton}, C., {McCarthy}, D., , C. (2015, nov). Near-Infrared and Optical colors of Trans-Neptunian Objects and Centaurs from Ground-Based Observations in Support of Spitzer Observations. In AAS/Division for Planetary Sciences Meeting Abstracts, 47.
• {Ward-Duong}, K., {Patience}, J., {Rosa}, R., {Bulger}, J., {Rajan}, A., {McCarthy}, D., {Kulesa}, C., {Goodwin}, S., , R. (2015, jan). The M-dwarfs in Multiples (MinMs) Survey - Stellar Multiplicity within 15 pc. In 18th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, 18.
• Beichman, C., Doyon, R., Greene, T., Hodapp, K., Horner, S., Krist, J., McCarthy, D., Meyer, M., Rieke, M., Stansberry, J., Stauffer, J., Trauger, J., & Team, N. (2014, mar). The Near-Infrared Camera on the James Webb Space Telescope: The Next Great Step in Exoplanet Research. In Search for Life Beyond the Solar System. Exoplanets, Biosignatures \amp Instruments, 4.
• Follette, K. B., McCarthy, D. W., Dokter, E. F., & Buxner, S. (2014, jan). Science Literacy's Neglected Twin: Numeracy. In American Astronomical Society Meeting Abstracts \#223, 223, #322.05.
• Follette, K., & McCarthy, D. (2014, jul). Science Literacy's Neglected Twin: Numeracy. In Ensuring Stem Literacy: A National Conference on STEM Education and Public Outreach, 483, 31.
• Lebofsky, L. A., McCarthy, D. W., Higgins, M. L., & Lebofsky, N. R. (2014, jul). NASA's Role in Addressing Misconceptions: Scale of Our Solar System and Other Planetary Systems. In Ensuring Stem Literacy: A National Conference on STEM Education and Public Outreach, 483, 187.
• Lebofsky, L. A., McCarthy, D. W., Higgins, M. L., & Lebofsky, N. R. (2014, nov). Using Exoplanet Models to Explore NGSS and the Nature of Science and as a Tool for Understanding the Scientific Results from NIRCam/JWST. In AAS/Division for Planetary Sciences Meeting Abstracts, 46, #212.17.
• Lebofsky, L. A., McCarthy, D. W., Higgins, M. L., Mueller, B., & Lebofsky, N. R. (2014, jul). Mission and Research Scientists in NASA EPO and STEM Education: The Results of 15 Years of EPO. In Ensuring Stem Literacy: A National Conference on STEM Education and Public Outreach, 483, 375.
• McCarthy, D. W., DeVore, E., & Lebofsky, L. (2014, jul). Inspiration is ''Mission Critical''. In Ensuring Stem Literacy: A National Conference on STEM Education and Public Outreach, 483, 449-457.
• Robertson, A., Hardegree-Ullman, K., Towner, A. P., Walker-LaFollette, A., Carleton, T., & McCarthy, D. W. (2014, jan). How to Make a Club from Scratch: The Beginning of the University of Arizona Astronomy Club. In American Astronomical Society Meeting Abstracts \#223, 223, #160.01.
• Ward-Duong, K., Patience, J., De Rosa, R. J., Rajan, A., Hinz, P., Skemer, A., Morzinski, K., Males, J., Close, L. M., McCarthy, D. W., & Kulesa, C. (2014, jan). A Direct Imaging Study to Search for and to Characterize Planetary Mass Companions. In IAU Symposium, 299, 74-75.
• Ward-Duong, K., Patience, J., Rosa, R. J., Rajan, A., Hinz, P., Skemer, A., Morzinski, K., Males, J., Close, L. M., McCarthy, D. W., & Kulesa, C. (2014, mar). Testing Atmospheric Models Across the Brown Dwarf/Planet Boundary with Benchmark Young Substellar Companions. In Search for Life Beyond the Solar System. Exoplanets, Biosignatures \amp Instruments, 4P.
• Higgins, M. L., Lebofsky, L. A., McCarthy, D. W., & Lebofsky, N. (2013, apr). Bringing Astronomy Activities and Science Content to Girls Locally and Nationally: A Girl Scout and NIRCam Collaboration. In Communicating Science: A National Conference on Science Education and Public Outreach, 473, 355.
• Hooper, E. J., McCarthy, D. W., Benecchi, S. D., Henry, T. J., Kirkpatrick, J. D., Kulesa, C., Oey, M. S., Regester, J., Schlingman, W. M., & Camp Staff, A. (2013, jan). Thinking Big for 25 Years: Astronomy Camp Research Projects. In American Astronomical Society Meeting Abstracts, 221, #246.10.
• Lebofsky, L. A., Ca ~nizo, T. L., Lebofsky, N. R., McCarthy, D. W., Higgins, M. L., & Salthouse, K. (2013, apr). Using Models to Address Misconceptions in Size and Scale Related to the Earth, Moon, Solar System, and Universe. In Communicating Science: A National Conference on Science Education and Public Outreach, 473, 285.
• Lebofsky, L. A., Lebofsky, N. R., McCarthy, D. W., Canizo, T. L., Schmitt, W., & Higgins, M. L. (2013, oct). Scientists and Educators Working Together: Everyone Teaches, Everyone Learns. In AAS/Division for Planetary Sciences Meeting Abstracts, 45, #117.05.
• McCarthy, D. W., Hooper, E., Benecchi, S. D., Henry, T. J., Kirkpatrick, J. D., Kulesa, C., Oey, M. S., Regester, J., Schlingman, W. M., & Camp Staff, A. (2013, jan). Lighting the Fire for 25 years: The Nature and Legacy of Astronomy Camp. In American Astronomical Society Meeting Abstracts, 221, #246.11.
• McCarthy, D., & Follette, K. (2013, apr). RE-NUMERATE: A Workshop to Restore Essential Numerical Skills and Thinking via Astronomy Education. In Communicating Science: A National Conference on Science Education and Public Outreach, 473, 79.
• McCarthy, D., Lebofsky, L. A., Schlingman, W. M., & Higgins, M. L. (2013, apr). Practical Lessons From the First Decade of EPO Partnership Between NIRCam/JWST and the GSUSA. In Communicating Science: A National Conference on Science Education and Public Outreach, 473, 289.
• Serna, G. E., Eckenrode, J., McCarthy, D. W., Wallace, C. S., Prather, E. E., Brissenden, G., Rudolph, A. L., & (CATS), C. (2013, jan). The California-Arizona Minority Partnership for Astronomy Research and Education (CAMPARE): Astronomy Education Research. In American Astronomical Society Meeting Abstracts, 221, #248.06.
• Follette, K. B., & McCarthy, D. W. (2012, jan). Fostering the Development of Quantitative Life Skills through Introductory Astronomy: Can it be Done?. In American Astronomical Society Meeting Abstracts #219, 219, #227.01.
• Lebofsky, L. A., Higgins, M. L., McCarthy, D. W., & Lebofsky, N. R. (2012, jan). Bringing Astronomy Activities and Science Content to Girls Locally and Nationally: A Girl Scout and NIRCam Collaboration. In American Astronomical Society Meeting Abstracts #219, 219, #350.06.
• Lebofsky, L. A., Higgins, M. L., McCarthy, D. W., & Lebofsky, N. R. (2012, mar). Bringing Astronomy Activities and Science Content to Girls Locally and Nationally: A Girl Scout NIRCam Collaboration. In Lunar and Planetary Science Conference, 43, 1303.
• Lebofsky, L. A., Lebofsky, N. R., McCarthy, D. W., Higgins, M. L., Salthouse, K., & Canizo, T. L. (2012, oct). Using Models to Address Misconceptions in Size and Scale Related to the Earth, Moon, Solar System, and Universe. In AAS/Division for Planetary Sciences Meeting Abstracts, 44, #411.06.
• Saldivar, H., McCarthy, D., & Rudolph, A. L. (2012, jan). The California-Arizona Minority Partnership for Astronomy Research and Education (CAMPARE): Partnering Students to Astronomy at the University of Arizona's Astronomy Camp. In American Astronomical Society Meeting Abstracts #219, 219, #147.04.

Presentations

• McCarthy, D. W., & Kerrigan, C. E. (2017, October). Faculty Programs: A Model for Student Affairs & Academic Affairs Collaboration to Promote Student Success & Retention. National Association of Student Personnel Administrators. Phoenix: NASPA.
• Follette, K., McCarthy, D. W., Dokter, E. F., & Buxner, S. R. (2014, August). The development and validation of an assessment tool for evaluating quantitative literacy in introductory science courses. Astronomical Society of the Pacific, Celebrating Science: Putting Education Best Practices to Work. Burlingame, CA.