UT Austin High Redshift Research Group

The University of Texas at Austin

Research Group Members

Click here for publications from our research group.

Dr. Isak Wold
Postdoctoral Research Associate
Isak joined UT in 2014, after receiving his PhD from the University of Wisconsin, Madison. Isak’s thesis work centered around using the GALEX grism spectroscopy to study Lyman alpha emitters (LAEs) at z~1. At UT, he is continuing this project, extending down to z~0.3, and he is also taking the lead on the imaging survey for the HETDEX Fall Field, where he will soon be studying the evolution of LAEs at z~2-3.

Jason Jaacks
5th year graduate student
Jason Jaacks came to UT in 2013 from the University of Nevada, Las Vegas. Jason recently completed a project using simulations to study methods of linking galaxies across cosmic time. He is working on his PhD project under the joint advisement of Prof Finkelstein and Prof Volker Bromm, with the goal of simulating the James Webb Space Telescope observations of the distant universe.

Intae Jung
5th year graduate student, NESSF Fellow
Intae Jung came to UT in 2013 from Yonsei University in South Korea. Intae’s first project focuses on using high-resolution Hubble imaging of z~4 galaxies to perform spatially-resolved stellar population modeling. He has found that galaxies with the highest central mass densities have star-formation rates in their centers which are being reduced compared to their outskirts. This implies that these galaxies are in the early phases of quenching, which is predicted by several models. This paper has been published on Jan 2017. After that, he is analyzing a Keck spectroscopic dataset to use Lyman alpha emission as a probe of reionization.

Matt Stevans
5th year graduate student
Matt came to UT in 2013 from the University of Colorado at Boulder. Matt’s current project is to use the extremely large area available from the HETDEX/SHELA survey (23 square degrees) to find the brightest and most massive galaxies in the z~4 universe. In his initial analysis, there was an intriguing overabundance of such galaxies, and he is now investigating possible explanations for this discovery. After this project, we will continue working with the HETDEX/SHELA data to study the process of quenching in massive, distant galaxies.

Briana Indahl
4th year graduate student
Briana came to UT in 2014 from the University of Wisconsin. She has spent her first few years both in the instrumentation lab, characterizing the instrument VIRUS, and also using the VIRUS-P IFU to map the outflow in M82. She will soon begin working on the data forthcoming from HETDEX to both understand where LAEs fit in the galaxy zoo, and also to probe the physical processes regulating Lyman alpha emission from galaxies.

Rebecca Larson
2nd year graduate student
Rebecca was an undergraduate at UT Austin, and has stayed on for her PhD. Her current project is to design software to scan Hubble Space Telescope slitless grism spectroscopic data to find faint emission lines, which are difficult to identify with a simple visual inspection. She will move on to prepare to work on data from the upcoming James Webb Space Telescope.

Undergraduate Students

Sofia Rojas
undergraduate student
Sofia is a junior astronomy and physics student who is working on Hubble pure parallel imaging data to search for galaxies at a redshift of 9.

Yaswant Devarakonda
undergraduate student
Yaswant is a senior astronomy and physics student who is working on the HETDEX project. He initially helped optimize the reduction of the ground-based imaging data, and he has moved on to being a leader of a group who is calibrating our emission line detection software.

Group Alumni

Mimi Song
PhD UT Austin 2016
Mimi obtained her PhD in 2016 with her dissertation titled "Tracing Galaxy Growth and Lyman-alpha Emission in the Early Universe". Mimi's thesis included the most robust measurement of the evolution of the galaxy stellar mass function from z=4-8, discovering that the low-mass-end slope evolves significantly over that epoch. She also discovered and spectroscopically confirmed a galaxy at z=7.66, one of the most distant known at that time. Mimi then won a prestegious NASA Postdoctoral Fellowship, which she currently holds at NASA Goddard Space Flight Center.

Dr. Rachael Livermore
Postdoc 2013-2017
Rachael Livermore was a postdoc member of our group for four years, where she made important contributions to the field of galaxy evolution by being the first to make full use of highly magnified sources from the Hubble Frontier Fields survey. She made use of wavelet decomposition techniques to subtract the light from the lensing galaxy cluster, discovering some of the faintest, most distant galaxies known, showing that the galaxy ultraviolet luminosity function extends ~5 magnitudes deeper than seen in the absense of lensing. Rachael also co-created the Austin branch of Astronomy on Tap.