Graduate Program in the News

2014  |  2013  |  2012


Marshall Johnson Wins 2015 David Alan Benfield Fellowship

marshall johnson

Marshall Johnson

November 2014

By faculty vote, Marshall Johnson has been awarded this year's David Alan Benfield Memorial Fellowship in Astronomy. Marshall has developed a major research program in Doppler tomography of exoplanet transits, and has quickly established himself as a world-leader in the field. Doppler tomography enables the confirmation of exoplanets orbiting rapidly rotating stars, which are not easily amenable to classical high precision radial velocity techniques. This enables us to extend studies of exoplanet formation and evolution, to stars significantly more massive than we have previously been able to study, and also to very young planetary systems.

Marshall has written his own tomographic analysis code from scratch, and his code is now out-performing existing codes by other much more senior researchers. Marshall works under the supervision of Dr. William Cochran.

Tim Weinzirl's Dissertation Selected for Springer Book Series

tim weinzirl

Tim Weinzirl

August 2014

Tim Weinzirl's 2013 Ph.D. thesis, "Probing Galaxy Evolution by Unveiling the Structure of Massive Galaxies Across Cosmic Time and in Diverse Environments", has been published as its own volume in the Springer Theses book series. Titles in the Springer Theses series are chosen based on their scientific excellence and broad impact on research. Tim's thesis received an initial invitation from Springer after he won the one of the Rodger Doxsey Travel prizes from the American Astronomical Society in January 2013. The book is available from Springer at this link:

Tim recently earned his PhD under the supervision of Shardha Jogee, and will begin a postdoctoral position at the University of Nottingham this Fall.

Yi-Kuan Chiang Wins 2014 Frank Edmonds Memorial Fellowship

yi-kuan chiang

Yi-Kuan Chiang

July 2014

Yi-Kuan Chiang has won the 2014 Frank Edmonds Memorial Fellowship. The fellowship is awarded annually by faculty vote to a second or third year student showing strong promise in research. Yi-Kuan works on the largest structures in the universe, clusters of galaxies, with Karl Gebhardt and Roderik Overzier, using numerical simulations to optimize search and analysis techniques for cluster progenitors at high redshift. Tracking clusters observationally at different evolutionary stages creates a robust picture of formation history. The techniques will be applied to the high redshift HETDEX survey. Yi-Kuan's two papers on the subject have been notably well received by the community.

Michael Gully-Santiago and Taylor Chonis Present Research at SPIE-Montreal

June 2014

Michael Gully-Santiago and Taylor Chonis presented research at the SPIE Astronomical Telescopes and Instrumentation conference in Montreal, Quebec in June. International experts assemble every two years to discuss state of the art instrumentation.

Taylor Chonis

Taylor's talk was based on work for the HET Wide Field Updgrade, "Mass production of volume phase holographic gratings for the VIRUS spectrograph array". Taylor has also designed and built a facility instrument for HET, presented in a poster, "LRS2: the new facility low resolution integral field spectrograph for the Hobby-Eberly telescope".

Michael Gully-Santiago

Michael Gully-Santiago presented work with silicon immersion gratings, innovations integral to the new Immersion Grating INfrared Spectrograph (IGRINS) instrument at McDonald Observatory. His poster, "High performance silicon immersion gratings patterned with electron beam lithography" describes work completed in partnership with Jet Propulsion Laboratory, Caltech, under a contract with NASA.

Jeremy Ritter Wins Board of Visitors Second Year Research Defense Award

jeremy ritter

Jeremy Ritter

May 2014

Jeremy Ritter has won this year's Board of Visitors Graduate Student Second Year Research Defense Award for his project entitled "Outflows and Chemical Enrichment from Clustered Supernovae in the First Galaxies". Jeremy has been working with Milos Milosavljevic on simulating the supernova explosions of the first stars in order to better understand their role in the assembly and chemical evolution of the first galaxies. He is especially interested in exploring the possibility that the ultra faint dwarf galaxies may be nearby relics of the first galaxies.

Mimi Song and Yi-Kuan Chiang Win UT Graduate School Continuing Fellowships

April 2014

Mimi Song (5th Year) and Yi-Kuan Chiang (3rd Year) have received highly competitive continuing fellowships from the UT Graduate School.

mimi song

Mimi Song

Mimi is currently working with Steve Finkelstein to understand how galaxies evolve in the early universe, by studying both individual galaxies using spectroscopic data and large sample of galaxies using imaging data. Currently, her project focuses on constraining the evolution of galaxy stellar mass function in the first two billion years after the Big Bang with the deepest Hubble and Spitzer data. This study is expected to provide more robust observational constraints in particular on the low-mass end slope of the galaxy stellar mass function, which is a critical test for current galaxy formation models.

yi-kuan chiang

Yi-Kuan Chiang

Yi-Kuan works with Karl Gebhardt and Roderik Overzier on pioneering statistical studies of the formation of galaxy clusters in the early universe. By combining sophisticated cosmological simulations, large galaxy surveys and detailed spectroscopic follow-ups, they identify and characterize the early progenitors of galaxy clusters and study both their dark and luminous components. This project brings 3 pillars of extragalactic astronomy together, namely dark matter structure formation, galaxy formation, and cluster formation. It will also inform the upcoming HETDEX survey that is scheduled to map out the distant universe and study the time evolution of dark energy.

Aaron Smith Wins NSF Graduate Research Fellowship

aaron smith

Aaron Smith

April 2014

Second-year graduate student Aaron Smith has been awarded a full NSF Graduate Research Fellowship. Aaron works with Volker Bromm on The Lyman-alpha signature of the first galaxies. His project focuses on different aspects of propagation of Lyman-alpha emission in early galaxies. The main tool is the Cosmic Lyman-alpha Transfer Code (COLT), developed by Aaron to connect with cosmological galaxy formation simulations. The high luminosity Lyman-alpha sources interact with their host environments according to the local density, ionization, and velocity structure. Theoretical predictions from such simulations coupled with observations made with current- and next-generation facilities, such as the James Webb Space Telescope (JWST), allow us to 'shed light on the cosmic Dark Ages.' The NSF fellowship provides 3 years of full support.

Tune In and Be 'Blinded With Science'

kvrx radio booth

Astronomy graduate student Michael Gully-Santiago hosts 'They Blinded Me with Science' on KVRX 91.7 Mondays at 8:30pm, discussing active research at the College of Natural Sciences and around the world. Find an archive at podcast, and enjoy this CNS news feature on the program.

223rd AAS Meeting - Washington, D.C. - January 2014

matt stevans

Graduate student Matt Stevans presents a poster on the NEWFIRM HETDEX Survey plan at the 223rd semiannual AAS meeting in Washington, D.C., which will gather extinction-corrected star-formation rates (SFRs) for ~400,000 galaxies at 2 < z < 3.5.