Reconciling Dwarf Galaxies With Λcdm Cosmology: Simulating a Realistic Population of Satellites Around a Milky Way–mass Galaxy
Year: 2016
Type: article
Abstract: 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 25 – 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.
Authors: Andrew R. Wetzel, Philip F. Hopkins, Ji-hoon Kim, Claude-André Faucher-Giguère, Dušan Kereš, Eliot Quataert
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Awards: G1422262692, G185792953, G1974252047, G2046453982, THE INSTALLATION OF THE COSMIC ORIGINS SPECTROGRAPH (COS) ON THE HUBBLE SPACE TELESCOPE (HST) AS PART OF ITS LAST SERVICING MISSION HAS REVOLUTIONIZE, Collaborative Research: CDS&E: FIRE: Physically-Predictive Cosmological Simulations of Galaxy Formation with Resolved Feedback, THE BIGGEST SHORTCOMING IN OUR MODELS OF STAR, SUPERMASSIVE BLACK HOLE, AND GALAXY FORMATION IS OUR POOR AND INCOMPLETE UNDERSTANDING OF 'FEEDBACK' P, CAREER: The Ties that (Un)Bind: Understanding the Connection Between Galaxies, Stars, and Black Holes, Collaborative Research: CDS&E: FIRE: Physically-Predictive Cosmological Simulations of Galaxy Formation with Resolved Feedback, G6671297155, Toward physically-predictive modeling of massive black hole growth and feedback in galaxy formation, Collaborative Research: CDS&E: FIRE: Physically-Predictive Cosmological Simulations of Galaxy Formation with Resolved Feedback, G7219850570, G7618195524, G7857352519, G8970859722
OpenAlex ID: W2281869457