Randall Dannen, PhD @ UNLV

Hello! I'm Randall Dannen, a postdoctoral scholar working with Dr. Daniel Proga and his research group. I'm a native to Las Vegas, and I've had a love for science and the natural world for as long as I can remember. I started my undergraduate career in 2009 and after dealing with some set backs, finally receiving bachelor's degrees in mathematics and physics in the year 2016. While completing my undergraduate degrees, I initially joined Dr. Ken Nagamine's research group working on early galaxy formation using the SPH code GADGET-3. Dr. Nagamine unfortunately departure from UNLV to Osaka before I graduated, so I joined Dr. Proga's group where I've gone on to complete the aforementioned bachelors', and master's and doctoral degrees in astronomy. I've been fortunate enough to continue working with Dr. Proga's group as a postdoctoral scholar after graduation.

Active galactic nueclei (AGN) are some of the most energetic objects in the universe, and are often hosts to accretion disks with winds providing important feedback from the central supermassive black hole (SMBH) to the rest of the galaxy. My efforts have been on modeling the conditions of these outflows and their spectral signatures using the photoionization code XSTAR and coupling the output with the radiation GRMHD code and adaptive mesh refinement (AMR) framework Athena++ . My recent efforts are focused on modeling spectra from AGN using the Monte-Carlo radiative transfer code SIROCCO .

• Smith, K., Proga, D., Dannen, R., Dyda, S., & Waters, T. (2024)
       Position-dependent Radiation Fields near Accretion Disks.
       The Astrophysical Journal, 970(2), 150. ADS
• Dannen, R., Proga, D., Waters, T., & Dyda, S. (2024)
      On the Transition from Efficient to Inefficient Line Driving in Irradiated Flows
       The Astrophysical Journal, 961(2), 221. ADS
• Waters, T., Proga, D., Dannen, R., & Dyda, S. (2022)
       Dynamical Thermal Instability in Highly Supersonic Outflows
       The Astrophysical Journal, 931(2), 134. ADS
• Ganguly, S., Proga, D., Waters, T., Dannen, R. C., Dyda, S., Giustini, M., Kallman, T., Raymond, J., Miller, J., & Rodriguez Hidalgo, P. (2021)
       On Synthetic Absorption Line Profiles of Thermally Driven Winds from Active Galactic Nuclei
       The Astrophysical Journal, 914(2), 114. ADS
• Waters, T., Proga, D., & Dannen, R. (2021)
       Multiphase AGN Winds from X-Ray-irradiated Disk Atmospheres
       The Astrophysical Journal, 914(1), 62. ADS
• Dannen, R. C., Proga, D., Waters, T., & Dyda, S. (2020)
       Clumpy AGN Outflows due to Thermal Instability
       The Astrophysical Journal Letters, 893(2), L34. ADS
• Dannen, R. C., Proga, D., Kallman, T. R., & Waters, T. (2019)
       Photoionization Calculations of the Radiation Force Due To Spectral Lines in AGNs
       The Astrophysical Journal, 882(2), 99. ADS
• Dyda, S., Dannen, R., Waters, T., & Proga, D. (2017)
       Irradiation of astrophysical objects - SED and flux effects on thermally driven winds
       Monthly Notices of the Royal Astronomical Society, 467(4), 4161–4173. ADS
• Waters, T., Proga, D., Dannen, R., & Kallman, T. R. (2017)
       Synthetic absorption lines for a clumpy medium: a spectral signature for cloud acceleration in AGN?
       Monthly Notices of the Royal Astronomical Society, 467(3), 3160–3171. ADS