10
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      The Impact of Wind Scalings on Stellar Growth and the Baryon Cycle in Cosmological Simulations

      Preprint

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Many phenomenologically successful cosmological galaxy formation simulations employ kinetic winds to model galactic outflows, a crucial ingredient in obtaining predictions that agree with various observations. Yet systematic studies of how variations in kinetic wind scalings might alter observable galaxy properties are rare. Here we employ GADGET-3 simulations to study how the baryon cycle, stellar mass function, and other galaxy and CGM predictions vary as a function of the assumed outflow speed \(v_w\) and the scaling of the mass loading factor \(\eta\) with velocity dispersion \(\sigma\). We design our fiducial model to reproduce the measured wind properties at 25% of the virial radius from the Feedback In Realistic Environments (FIRE) simulations. We find that a strong dependence of \(\eta \sim \sigma^5\) in low mass haloes with \(\sigma < 106\ \mathrm{km\ s^{-1}}\) is required to match the faint end of the stellar mass functions at \(z > 1\). The wind speed also has a major impact, with faster winds significantly reducing wind recycling and heating more halo gas. Both effects result in less stellar mass growth in massive haloes and impact high ionization absorption in halo gas. We cannot simultaneously match the stellar content at \(z=2\) and \(z=0\) within a single model, suggesting that an additional feedback source such as AGN might be required in massive galaxies at lower redshifts, but the amount needed depends strongly on assumptions regarding the outflow properties. We run a 50 \(\mathrm{Mpc/h}\), \(2\times576^3\) simulation with our fiducial parameters and show that it matches a range of star-forming galaxy properties at \(z\sim0-2\). In closing, the results from simulations of galaxy formation are much more sensitive to small changes in the feedback implementation than to the hydrodynamic technique.

          Related collections

          Author and article information

          Journal
          17 October 2019
          Article
          1910.08199
          7a2f3886-1bf1-4089-bbf1-a3fc8773b5e8

          http://arxiv.org/licenses/nonexclusive-distrib/1.0/

          History
          Custom metadata
          31 pages, 19 figures, submitted to MNRAS
          astro-ph.GA

          Galaxy astrophysics
          Galaxy astrophysics

          Comments

          Comment on this article