Introduction

A Relatively Short Bio

As you might have guessed from the title of this webpage, my name is Randall Dannen, a Ph.D. student at UNLV working with Dr. Daniel Proga and his research grouping including, Dr. Sergei Dyda , Dr. Tim Waters , and Shalini Ganguly. I'm a Las Vegas native, and have been interested in science since a very young age. I started working on my Bachelor's in physics and mathematics in 2009, but life often throws you curve balls, making my graduation not until 2016. During that time, I've worked with Dr. Ken Nagimine's research group on early galaxy formation and attempting to address the dwarf galaxy problem. After Dr. Nagimine's departure from UNLV to Osaka, I joined Dr. Proga's group modeling active galactic nuclei (AGN). Work I'm still continuing, receiving an M.S. in astronomy in 2018 and (hopefully) finishing my PhD within the next couple of years.

Research

We have been working on modeling outflows from AGN, and to do so, we've combined the photoionzation code XSTAR to determine the heating and cooling rates and line opacities for a given spectral energy distribution (SED) and the magnetohydrodynamic code Athena++ to simulate different types of physical scenarios. See our project webpages [ 1 & 2 ] for additional movies and more details about the methods used to obtain these results. The movies bellow are for a particular case where we find a clumpy outflow using the unobscured AGN SED from NGC 5548.

Papers

  1. Clumpy AGN outflows due to thermal instability
    2.
  2. Dannen R., Proga D., Waters T., & Dyda S., 2019, arXiv, arXiv:2001.00133
  3. Photoionization Calculations of the Radiation Force Due To Spectral Lines in AGNs
    4.
  4. Dannen R. C., Proga D., Kallman T. R., & Waters T., 2019, ApJ, 882, 99
  5. Synthetic absorption lines for a clumpy medium: a spectral signature for cloud acceleration in AGN?
    6.
  6. Waters, T., Proga, D., Dannen, R., & Kallman, T. 2017, MNRAS, Volume 467, Issue 3, p.3160-3171
  7. Irradiation of astrophysical objects - SED and flux effects on thermally driven winds
    8.
  8. Dyda, S., Dannen, R., Waters, T., & Proga, D. 2017, MNRAS, Volume 467, Issue 4, p.4161-4173

Teaching

  • Spring 2020
  • PHYS 180L
  • PHYS 181L
Previous Semesters
  • Fall 2019
  • PHYS 151
  • Spring 2019
  • PHYS 151
  • Fall 2018
  • PHYS 180L
  • Spring 2018
  • PHYS 181L
  • Fall 2017
  • PHYS 180L
  • PHYS 181L
  • Spring 2017
  • PHYS 180L
  • PHYS 181L
  • Fall 2016
  • PHYS 181L
  • PHYS 151L

Contact

  • Email
    dannenr at unlv.nevada.edu
  • Mailing Address
    Department of Physics & Astronomy
    University of Nevada, Las Vegas
    4505 South Maryland Parkway
    Box 454002
    Las Vegas, NV 89154-4002