Research Interests

Cosmology and galaxy formation, including:

• the formation, evolution, and structure of galaxies and dark matter halos
• near-field cosmology
• the nature of dark matter
• dynamics of dwarf galaxies and the Local Group (including the ELVIS suite and the HSTPROMO collaboration)
• globular cluster formation and evolution
• cosmic reionization
• numerical simulations (I led the Millennium-II Simulation; follow links for movies, images, scientific papers, and data access)

Group Members

• Jenna Samuel (NSF postdoc: near-field cosmology, satellite planes, ram pressure's effects on satellites)
• Anna Schauer (postdoc: pop III star formation, effects of baryon-dark matter streaming velocities on galaxy formation)
• Hyunsu Kong (grad student: dark matter distributions on sub-galactic scales)
• Maria Straight (grad student, former REU undergrad: density profiles in simulated dwarf galaxies, particle cosmology)
• Connor Painter (grad student: fuzzy dark matter)
• Resherle Verna (grad student: self-interacting dark matter)

Alumni

• Alex Fitts (PhD 2018: cosmological simulations of dwarf galaxy formation)
• Brandon Bozek (postdoc: dark matter astrophysics, cosmological simulations)
• Corbin Taylor (grad student, Maryland: the mass distribution of the Milky Way as inferred from numerical simulations)
• Harold Johnson (grad student: the Local Group through cosmic time)
• Emily Strickland (undergrad: simulations with self-interacting dark matter)
• Rebecca Tippens (grad student: statistical astrophysics; satellite phase-space correlations)
• Alex Lazar (undergrad: dynamics in dark matter simulations versus hydrodynamical simulations)
• Elizabeth Gutiérrez (undergrad: high-redshift phenomena in galaxy formation)
• Olti Myrtaj (REU student: self-interacting dark matter)
• Andrew Graus (Harlan J. Smith postdoc: dwarf galaxies, dark matter, radial gradients)
• Omid Sameie (postdoc: the nature of dark matter, globular clusters)
• Adam McCarron (grad student: the halo-galaxy connection and machine learning)
• Kate Colston (undergrad: streaming velocity's effects on halo properties)
• Rylie Phillips (undergrad: reionization's effects on dwarf galaxies in the Local Group)

Long-term collaborations

• James Bullock (UC Irvine)
• Michael Cooper (UC Irvine)
• Mark Vogelsberger (MIT)
• Dan Weisz (UC Berkeley)
• FIRE (Feedback In Realistic Environments)

Some Research Highlights:

Too big to fail? The puzzling darkness of massive Milky Way subhalos
M. Boylan-Kolchin, J. S. Bullock, & M. Kaplinghat (2011), MNRAS, 415, L40
Scientific American summary

The Space Motion of Leo I: The Mass of the Milky Way's Dark Matter Halo
M. Boylan-Kolchin, J. S. Bullock, S. T. Sohn, G. Besla, & R. P. van der Marel (2013), ApJ, 768, 140
Scientific American write-up

Segue 2: The Least Massive Galaxy
E. Kirby, M. Boylan-Kolchin, J. Cohen, M. Geha, M. Kaplinghat, & J. S. Bullock (2013), ApJ, 770, 16
Press: NY Times, LA Times, New Scientist, Time

ELVIS: Exploring the Local Volume in Simulations
S. Garrison-Kimmel, M. Boylan-Kolchin, J. Bullock, K. Lee (2014), MNRAS, 438, 2596
website (including simulation data)

Near-Field Limits on the Role of Faint Galaxies in Cosmic Reionization
M. Boylan-Kolchin, J. Bullock, S. Garrison-Kimmel (2014), MNRAS, 443, L44

The Local Group as a Time Machine: Studying the High-Redshift Universe with Nearby Galaxies
M. Boylan-Kolchin, D. Weisz, B. Johnson, J. Bullock, C. Conroy, A. Fitts (2015), MNRAS, 453, 1503
Harvard/Smithsonian Center for Astrophysics Science Update

The Local Group: The Ultimate Deep Field
M. Boylan-Kolchin, D. Weisz, J. Bullock, M. Cooper (2016), MNRAS, 462, L51
Science Editors' Choice pick

The Little Engines That Could? Globular Clusters Contribute Significantly to Reionization-era Star Formation
M. Boylan-Kolchin (2018), MNRAS, 479, 332
astrobites write-up and second write-up

We gratefully acknowledge grant support from the NSF and NASA, as well as computing resources from NSF’s Extreme Science and Engineering Discovery Environment (XSEDE), The University of Texas through the Texas Advanced Computing Center (TACC), and NASA’s High-End Computing facilities (NAS and NCCS).