Alyson Ford

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Scholarly Contributions

Journals/Publications

• Collaboration, E., Akiyama, K., Algaba, J. C., Alberdi, A., Alef, W., Anantua, R., Asada, K., Azulay, R., Baczko, A., Ball, D., Balokovi{\'c}, M., Barrett, J., Benson, B. A., Bintley, D., Blackburn, L., Blundell, R., Boland, W., Bouman, K. L., Bower, G. C., , Boyce, H., et al. (2021). First M87 Event Horizon Telescope Results. VII. Polarization of the Ring. \apjl, 910(1), L12.
• Collaboration, E., Akiyama, K., Algaba, J. C., Alberdi, A., Alef, W., Anantua, R., Asada, K., Azulay, R., Baczko, A., Ball, D., Balokovi{\'c}, M., Barrett, J., Benson, B. A., Bintley, D., Blackburn, L., Blundell, R., Boland, W., Bouman, K. L., Bower, G. C., , Boyce, H., et al. (2021). First M87 Event Horizon Telescope Results. VIII. Magnetic Field Structure near The Event Horizon. \apjl, 910(1), L13.
• Goddi, C., Mart{\'\i-Vidal}, I., Messias, H., Bower, G. C., Broderick, A. E., Dexter, J., Marrone, D. P., Moscibrodzka, M., Nagai, H., Algaba, J. C., Asada, K., Crew, G. B., G{\'omez}, J. L., Impellizzeri, C. V., Janssen, M., Kadler, M., Krichbaum, T. P., Lico, R., Matthews, L. D., , Nathanail, A., et al. (2021). Polarimetric Properties of Event Horizon Telescope Targets from ALMA. \apjl, 910(1), L14.
• Group, E., Algaba, J., Anczarski, J., Asada, K., Balokovi{\'c}, M., Chandra, S., Cui, Y. -., Falcone, A., Giroletti, M., Goddi, C., Hada, K., Haggard, D., Jorstad, S., Kaur, A., Kawashima, T., Keating, G., Kim, J. -., Kino, M., Komossa, S., , Kravchenko, E., et al. (2021). Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign. \apjl, 911(1), L11.
• Janssen, M., Falcke, H., Kadler, M., Ros, E., Wielgus, M., Akiyama, K., Balokovi{\'c}, M., Blackburn, L., Bouman, K. L., Chael, A., Chan, C., Chatterjee, K., Davelaar, J., Edwards, P. G., Fromm, C. M., G{\'omez}, J. L., Goddi, C., Issaoun, S., Johnson, M. D., , Kim, J., et al. (2021). Event Horizon Telescope observations of the jet launching and collimation in Centaurus A. Nature Astronomy, 5, 1017-1028.
• Kocherlakota}, P., Rezzolla, L., Falcke, H., Fromm, C. M., Kramer, M., Mizuno, Y., Nathanail, A., Olivares, H., Younsi, Z., Akiyama, K., Alberdi, A., Alef, W., Algaba, J. C., Anantua, R., Asada, K., Azulay, R., Baczko, A., Ball, D., Balokovi{\'c}, M., , Barrett, J., et al. (2021). Constraints on black-hole charges with the 2017 EHT observations of M87*. \prd, 103(10), 104047.
• Narayan, R., Palumbo, D. C., Johnson, M. D., Gelles, Z., Himwich, E., Chang, D. O., Ricarte, A., Dexter, J., Gammie, C. F., Chael, A. A., Collaboration, E., Akiyama, K., Alberdi, A., Alef, W., Algaba, J. C., Anantua, R., Asada, K., Azulay, R., Baczko, A., , Ball, D., et al. (2021). The Polarized Image of a Synchrotron-emitting Ring of Gas Orbiting a Black Hole. \apj, 912(1), 35.
• Di Teodoro, E. M., McClure-Griffiths, N. M., Lockman, F. J., Denbo, S. R., Endsley, R., Ford, H. A., & Harrington, K. (2018). Blowing in the Milky Way wind: neutral hydrogen clouds tracing the Galactic nuclear outflow. ApJ.
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  We present the results of a new sensitive survey of neutral hydrogen aboveand below the Galactic Center with the Green Bank Telescope. The observationsextend up to Galactic latitude | b | < 10 deg with an effective angularresolution of 9.5' and an average rms brightness temperature noise of 40 mK ina 1 km/s channel. The survey reveals the existence of a population of anomaloushigh-velocity clouds extending up to heights of about 1.5 kpc from the GalacticPlane and showing no signature of Galactic rotation. These clouds have localstandard of rest velocities | Vlsr | < 360 km/s and, assuming a Galactic Centerorigin, they have sizes of a few tens of parsecs and neutral hydrogen massesspanning $10-10^5 \, M_\odot$. Accounting for selection effects, the cloudpopulation is symmetric in longitude, latitude, and Vlsr. We model the cloudkinematics in terms of an outflow expanding from the Galactic Center and findthe population consistent with being material moving with radial velocity Vw ~330 km/s distributed throughout a bi-cone with opening angle $\alpha>140$ deg.This simple model implies an outflow luminosity $Lw > 3 \times 10^{40}$ erg/sover the past 10 Myr, consistent with star formation feedback in the innerregion of the Milky Way, with a cold gas mass-loss rate $\lesssim 0.1 \,M_\odot$/yr. These clouds may represent the cold gas component accelerated inthe nuclear wind driven by our Galaxy, although some of the derived propertieschallenge current theoretical models of the entrainment process.[Journal_ref: ]
• HI4PI Collaboration, ., & Ford, H. A. (2016). HI4PI: A full-sky H I survey based on EBHIS and GASS. Astronomy & Astrophysics, 594. doi:10.1051/0004-6361/201629178

Proceedings Publications

• Johnson, M. C., McQuinn, K. B., Cannon, J., Martinkus, C., Skillman, E., Bailin, J., Ford, H. A., Hunt, L., Westmeier, T., Wong, O. I., & Kamphuis, P. (2019, oct). The Hi Neighborhoods Around STARBIRDS. In Dwarf Galaxies: From the Deep Universe to the Present, 344.
• Pearce, E. C., Ford, H. A., Reddy Kanupuru, V. V., Schildknecht, T., & Block, A. (2017, September). Rapid Characterization of Geosynchronous Space Debris with 5-color Near-IR Photometry. In Advanced Maui Optical and Space Surveillance Technologies (AMOS) Conference 2017.
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  The characterization of deep space debris has posed a significant challenge in SSA. To be most operationally effective, characterization must be performed quickly and under non-ideal operational conditions, generally using non-imaging techniques. The use of multi-color photometry and the resultant color indices in the near and short wave IR offer the potential to rapidly discriminate between debris and intact space objects such as rocket bodies and satellites. Specifically, the color indices surrounding the near IR Z band (0.83-0.925 µm) show promise to differentiate materials while providing a more efficient data collection when compared to spectroscopic techniques. Similar techniques have been demonstrated in the astronomical community to discriminate between different classes of near Earth asteroids. The diagnostic attributes of the Z band are particularly compelling as similar diagnostic color indices can be measured using visible telescopes and the corresponding Sloan z’ band. Initial results of an extensive survey of cataloged debris, high area-to-mass ratio (HAMR) debris, rocket bodies, and intact satellites with the UKIRT WFCAM are presented to assess the efficacy of these techniques.

Presentations

• Ford, H. A. (2020, 03-11-2020). Steward Observatory’s Radio Telescopes: Recent Advancements and Future Developments (Invited Talk). 31st IEEE International Symposium on Space Terahertz Technology.
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  Invited talk at the 31st IEEE International Symposium on Space Terahertz Technology.
• Ford, H. A. (2018, Fall). An Overview of the Arizona Radio Observatory. Department of Astronomy/Steward Observatory Internal Symposium.
• Ford, H. A., Bregman, J., Hodges-Kluck, E., & Bailin, J. (2017, March). The Search for Extended HI Disks around Nearby Spirals. On the Origin (and Evolution) of Baryonic Galaxy Halos.
• Pearce, E. C., & Ford, H. A. (2017, 2017-04-12). Rapid Photometric Classification and Characterization of Space Objects. Non-Imaging Space Object Identification (NISOI) Workshop 2017. University of Arizona/LPL: Air Force Research Laboratory.
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  An overview of the Steward Observatory satellite photometry program (led by Pearce) is presented along with preliminary results from the UKIRT near IR survey. Initial results focus on rapid discrimination of SL-12 rocket bodies with 5-color near-IR spectrophotometry. The NISOI Workshops are a series of working level meetings organized by AFRL/DE and held twice a year. Participation in the workshop is by invitation only and the presentation and discussion of preliminary results and in process work is strongly encouraged. This year is the first year that a University is hosting the Workshop on behalf of AFRL.
• Pearce, E. C., Ford, H. A., Reddy Kanupuru, V. V., Schildknecht, T., & Block, A. (2017, September). Rapid Characterization of Geosynchronous Space Debris with 5-color Near-IR Photometry. Advanced Maui Optical and Space Surveillance Technologies (AMOS) Conference 2017.
  More info

  The characterization of deep space debris has posed a significant challenge in SSA. To be most operationally effective, characterization must be performed quickly and under non-ideal operational conditions, generally using non-imaging techniques. The use of multi-color photometry and the resultant color indices in the near and short wave IR offer the potential to rapidly discriminate between debris and intact space objects such as rocket bodies and satellites. Specifically, the color indices surrounding the near IR Z band (0.83-0.925 µm) show promise to differentiate materials while providing a more efficient data collection when compared to spectroscopic techniques. Similar techniques have been demonstrated in the astronomical community to discriminate between different classes of near Earth asteroids. The diagnostic attributes of the Z band are particularly compelling as similar diagnostic color indices can be measured using visible telescopes and the corresponding Sloan z’ band. Initial results of an extensive survey of cataloged debris, high area-to-mass ratio (HAMR) debris, rocket bodies, and intact satellites with the UKIRT WFCAM are presented to assess the efficacy of these techniques.
• Ford, H. A. (2016, September). The Search for Highly Extended HI Disks around Spiral Galaxies. Department of Astronomy/Steward Observatory Internal Symposium.

Poster Presentations

• Johnson, M., McQuinn, K., Cannon, J., Martinkus, C., Skillman, E., Bailin, J., Ford, H. A., Hunt, L., Westmeier, T., Wong, O. I., & Kamphuis, P. (2018, August). The HI Neighborhoods Around STARBIRDS. IAU Symposium #344 (Dwarf Galaxies: From the Deep Universe to the Present).