My name is Jenna Samuel. I am a Ph.D. candidate in astrophysics at the University of California, Davis. My research focuses on using cosmological simulations to understand how the dynamics of satellite dwarf galaxies impact their formation history. I am particularly interested in understanding the satellites of our own galaxy, the Milky Way, and those of our neighboring galaxy, Andromeda.

Learn about my research


Curriculum Vitae

I use simulations of galaxies to understand our own galaxy, the Milky Way. The particular simulations that I use (the Latte simulations) are part of the FIRE (Feedback In Realistic Environments) project, which is a suite of fully cosmological hydrodynamic zoom-in simulations. These simulations start out at high redshift (early times) with only low resolution dark matter particles which are perturbed according to Cosmic Microwave Background constraints. The simulation is evolved to redshift 0 (today), at which point a Milky Way-like dark matter halo is chosen for re-simulation at higher resolution (“zoom-in” simulation) with dark matter, star particles, and hydrodynamical gas particles.

I have recently submitted a paper, A profile in FIRE, that explores the radial distribution of satellite galaxies around both isolated Milky Way-like galaxies and paired Local Group-like systems in cosmological simulations. Radial distributions are important because they allow us to test our models of galaxy formation against observations in our cosmological neighborhood. The radial concentration, or how clustered satellites are towards their host galaxy, is also important in studies of spatial and kinematic coherence of satellites, such as the satellite plane problem.

My current work is aimed at investigating the problem of satellite planes in simulations. The satellite plane problem is the apparent spatial and kinematic coherence of the Milky Way’s satellites in a rotating plane or disk structure. Previous studies that have looked for such planes in simulations have largely come up empty handed, implying that maybe what we observe around the Milky Way is exceedingly rare. My work on the subject seeks to disentangle the prevalence of a planar structure from other biasing characteristics of the satellite distribution such as radial concentration. In the future, I will be working on a project that ties the dynamics of satellites to their formation history. Specifically, I want to disentangle the roles of internal stellar feedback (supernovae, stellar winds, and photoionization pressure and heating) and external halo environment (hot, pressure-supported gas in the Milky Way’s halo exerting ram pressure stripping) in regulating the gas content and star formation of satellites.

In the past I have done research on accreting supermassive black holes at the centers of galaxies, called active galactic nuclei (AGN). For this research I used the technique of reverberation mapping (RM), measuring the time lag in variability coming from an AGN at different wavelengths/energies. In particular, I used broad line RM where the time lag was measured between V band continuum luminosity and H-beta broad line emission. As an undergraduate, my first research experience was at Thomas Jefferson National Laboratory through the Science Undergraduate Laboratory Internship (SULI) program. I worked to characterize the properties of multi-anode photomultiplier tubes that were to be used in a ring-imaging Cherenkov detector.

Outreach & Teaching

Since late 2017 I have been a member of the UC Davis Diversity and Inclusion in Physics (DIP) group. We meet weekly to discuss issues of equity within our department and brainstorm ideas to remedy them that we then communicate to our faculty. You can find diversity, equity, and inclusion resources on our website, Davis DIP.

Once a month I help put on a local public astronomy event called Astronomy on Tap at Sudwerk Brewery in Davis. It features two short talks by astronomers and short segments about current events in astronomy. The event always draws a crowd of all ages and gives me a chance to answer people’s questions and let them know what goes on in their local physics and astronomy department.

In 2018, I organized a graduate student study group that strove to further a broad scientific understanding of astronomy while providing necessary professional development experiences like presentations, CV writing, and website building. Our biweekly meetings were peer-led and helped us learn about each other’s research in detail, discuss review articles, or peer review fellowship application materials.

As a graduate student I have been a Teaching Assistant for introductory physics labs (both mechanics and electromagnetism). I have also acted as Course TA for lectures in introductory astronomy, physics for non-science majors, and upper division math methods for physics majors. All of these roles included time spent grading and giving feedback to students, as well as leading office hours and lab sections.

As an undergraduate at Florida International University I participated in the Learning Assistant program. This was my first teaching experience and I helped facilitate introductory physics (mechanics) labs for two years before moving on to helping run the modern physics labs and lecture. There I helped students run and understand some of the most pivotal physics experiments of the 20th century, from demonstrating the photoelectric effect to the double-slit experiment.