1997/11/12 by John Hultman, Hultman, John, Daniel Kaellander +1
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics (astro-ph) #Astrophysics and Star Formation Studies #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9711138
12 pages, 21 figures. Astronomy and Astrophysics (final manuscript submitted)
arxiv created 1997/11/12 · openalex publication_date 1997/11/12 · arxiv updated 2009/12/01 · openalex created_date 2019/06/27 · openalex updated_date 2026/07/28
We present hydrodynamical simulations of the formation of galaxies in the mass range 109 - 1013 solar masses, with the focus on the efficiency of gas cooling. The effect of a background UV radiation field, and the effect of metal enrichment of halo gas due to star formation and stellar evolution, are investigated. A background radiation field is found to strongly suppress the formation of galaxies with circular velocities less than approximately 50 km/s. The effect is, however, not large enough to reconcile hierarchical clustering models with observations. Metal enrichment of the halo gas increases the cooling rate at low redshifts. We find that the mass fraction of gas at virial temperatures may be reduced by a factor of two, in simulations with a UV background field added. The decrease in overall efficiency of gas cooling due to the inclusion of a UV background field can be more than compensated for by the increased cooling that follows metal enrichment of halo gas, but the effect may depend strongly on the assumed model of metal enrichment.