The Research Team

Geha Group 2011

The Geha group meets weekly on Mondays.   If you are interested in joining us, please read here.




Marla GehaMarla Geha

Associate Professor
Marla is an associate professor in Astronomy, with a secondary appointment in Physics.  She graduated from Cornell University with a B.S. in Applied Physics and earned a Ph.D in Astronomy and Astrophysics from the University of California, Santa Cruz.  Before coming to Yale in 2008, she was a Plaskett Fellow at the HIA in Victoria, Canada, and a Hubble Fellow at the Carnegie Observatory in Pasadena. 


Postdoctoral Fellows

Erik-WFErik Tollerud

Hubble Fellow
Erik is a Hubble Fellow working in the Astronomy department at Yale. He earned a B.S. in Physics at the University of Puget Sound, and his PhD in Physics & Astronomy at the University of California, Irvine. His research interests focus on dSph galaxies of the Local Group and their connection to cosmology.

Graduate Students

NhungNhung Ho

Nhung is a sixth year graduate student in the Astronomy department at Yale. She completed her B.A. in Astrophysics at the University of California, Berkeley. While at Berkeley she was an undergraduate researcher with the Supernova Factory at Lawrence Berkeley National Labs. Current research involves studying the dynamical evolution of the M31 dwarf system with a side interest in environment driven evolution of local dwarfs.




Luis Vargas

Luis is currently in his fourth year at Yale. He completed his B.S in Physics and Astronomy at the University of Kansas. Years before that, he was born and raised in Lima, Peru. Luis is interested in everything related to the Milky Way and the Local Group, but is currently most interested in studying the evolution of dwarf spheroidal galaxies in the Milky Way system using chemical abundances of their constituent stars. He is also involved in research projects focusing on chemical abundances in the Milky Way halo, and Andromeda.



Ana Bonaca

Ana is a graduate student working with Marla Geha on tidal streams. Her first year project in the Geha group resulted in a discovery of a stellar tidal stream in the Milky Way halo. She is now analyzing simulated streams to discover the link between their 6D phase space distribution and the underlying gravitational potential. Ana is originally from Croatia, where she got a M.S. in Physics from University of Zagreb.


j_bradfordJeremy Bradford

Jeremy Bradford is an astronomy graduate student at Yale University.   He is interested in the dark matter content, the evolution and the dynamics of galaxies.  His research involves multi-wavelength observations of isolated low mass galaxies.  He is interested in testing Lambda-CDM cosmology using isolated galaxies in order to minimize the complex physics involved in modeling galaxy-galaxy interactions.  Jeremy is from Connecticut and obtained his B.S. in Mathematics and Physics from Central Connecticut State University in 2012.


Undergraduate Students

emily_pic_square2Emily Sandford

Yale Senior and STARS II fellow.




Former Geha Group Members: