Reconciling Dwarf Galaxies with ΛCDM Cosmology: Simulating A Realistic Population of Satellites Around a Milky Way-Mass Galaxy
Abstract
Low-mass "dwarf" galaxies represent the most significant challenges to the cold dark matter (CDM) model of cosmological structure formation. Because these faint galaxies are (best) observed within the Local Group (LG) of the Milky Way (MW) and Andromeda (M31), understanding their formation in such an environment is critical. We present first results from the Latte Project: the Milky Way on Feedback in Realistic Environments (FIRE). This simulation models the formation of an MW-mass galaxy to z = 0 within ΛCDM cosmology, including dark matter, gas, and stars at unprecedented resolution: baryon particle mass of 7070 M_⊙ with gas kernel/softening that adapts down to 1 pc (with a median of 2-60 pc at z = 0). Latte was simulated using the GIZMO code with a mesh-free method for accurate hydrodynamics and the FIRE-2 model for star formation and explicit feedback within a multi-phase interstellar medium. For the first time, Latte self-consistently resolves the spatial scales corresponding to half-light radii of dwarf galaxies that form around an MW-mass host down to M_(star) ≳ 10^5 M_⊙. Latte's population of dwarf galaxies agrees with the LG across a broad range of properties: (1) distributions of stellar masses and stellar velocity dispersions (dynamical masses), including their joint relation; (2) the mass–metallicity relation; and (3) diverse range of star formation histories, including their mass dependence. Thus, Latte produces a realistic population of dwarf galaxies at M_(star) ≳ 10^5 M_⊙ that does not suffer from the "missing satellites" or "too big to fail" problems of small-scale structure formation. We conclude that baryonic physics can reconcile observed dwarf galaxies with standard ΛCDM cosmology.
Additional Information
© 2016. The American Astronomical Society. Received 2016 February 18. Accepted 2016 July 29. Published 2016 August 12. We thank Andrew Benson, Mike Boylan-Kolchin, James Bullock, Aflis Deason, Shea Garrison-Kimmel, Marla Geha, Evan Kirby, Robyn Sanderson, Josh Simon, Erik Tollerud, Risa Wechsler for enlightening discussions, Dan Weisz for sharing observations, and Peter Behroozi for sharing rockstar. We acknowledge support from: Moore Center for Theoretical Cosmology and Physics at Caltech (A.R.W.); Sloan Research Fellowship, NASA ATP grant NNX14AH35G, NSF Collaborative Research grant 1411920 and CAREER grant 1455342 (P.F.H.); Einstein Postdoctoral Fellowship, NASA grant PF4-150147 (J.K.); NSF grants AST-1412836 and AST-1517491, NASA grant NNX15AB22G, and STScI grant HST-AR-14293.001-A (C.-A.F.-G.); NSF grant AST-1412153 and funds from UCSD (D.K.); NASA ATP grant 12-APT12-0183 and Simons Foundation Investigator award (E.Q.). We used computational resources from the Extreme Science and Engineering Discovery Environment (XSEDE), supported by NSF. A.R.W. also acknowledges support from lattes.Attached Files
Published - apjl_827_2_L23.pdf
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Additional details
- Eprint ID
- 70179
- Resolver ID
- CaltechAUTHORS:20160906-220609945
- Caltech Moore Center for Theoretical Cosmology and Physics
- Alfred P. Sloan Foundation
- NASA
- NNX14AH35G
- NSF
- AST-1411920
- NSF
- AST-1455342
- NASA Einstein Fellowship
- PF4-150147
- NSF
- AST-1412836
- NSF
- AST-1517491
- NASA
- NNX15AB22G
- NASA
- HST-AR-14293.001-A
- NSF
- AST-1412153
- University of California San Diego
- NASA
- 12-APT12-0183
- Simons Foundation
- Gordon and Betty Moore Foundation
- Carnegie Observatories Graduate Research Fellowship
- Created
-
2016-09-07Created from EPrint's datestamp field
- Updated
-
2021-11-11Created from EPrint's last_modified field
- Caltech groups
- TAPIR, Moore Center for Theoretical Cosmology and Physics