skip to main content

Title: COSMOLOGICAL SIMULATIONS OF GALAXY FORMATION WITH COSMIC RAYS

We investigate the dynamical impact of cosmic rays (CR) in cosmological simulations of galaxy formation using adaptive-mesh refinement simulations of a 10{sup 12} M {sub ☉} halo. In agreement with previous work, a run with only our standard thermal energy feedback model results in a massive spheroid and unrealistically peaked rotation curves. However, the addition of a simple two-fluid model for CRs drastically changes the morphology of the forming disk. We include an isotropic diffusive term and a source term tied to star formation due to (unresolved) supernova-driven shocks. Over a wide range of diffusion coefficients, the CRs generate thin, extended disks with a significantly more realistic (although still not flat) rotation curve. We find that the diffusion of CRs is key to this process, as they escape dense star-forming clumps and drive outflows within the more diffuse interstellar medium.
Authors:
;  [1] ;  [2]
  1. Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027 (United States)
  2. Department of Astronomy and Steward Observatory, University of Arizona, 933 North Cherry Avenue, N309, Tucson, AZ 85721 (United States)
Publication Date:
OSTI Identifier:
22364843
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 797; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMPUTERIZED SIMULATION; COSMIC RADIATION; COSMOLOGICAL MODELS; COSMOLOGY; DIAGRAMS; DIFFUSION; GALACTIC EVOLUTION; GALAXIES; MORPHOLOGY; ROTATION; SPHEROIDS; STARS