HI discs of L$_{\ast}$ galaxies as probes of the baryonic physics of galaxy evolution

Bibliographic Details
Title: HI discs of L$_{\ast}$ galaxies as probes of the baryonic physics of galaxy evolution
Authors: Gensior, Jindra, Feldmann, Robert, Reina-Campos, Marta, Trujillo-Gomez, Sebastian, Mayer, Lucio, Keller, Benjamin W., Wetzel, Andrew, Kruijssen, J. M. Diederik, Hopkins, Philip F., Moreno, Jorge
Publication Year: 2023
Collection: Astrophysics
Subject Terms: Astrophysics - Astrophysics of Galaxies
More Details: Understanding what shapes the cold gas component of galaxies, which both provides the fuel for star formation and is strongly affected by the subsequent stellar feedback, is a crucial step towards a better understanding of galaxy evolution. Here, we analyse the HI properties of a sample of 46 Milky Way halo-mass galaxies, drawn from cosmological simulations (EMP-Pathfinder and FIREbox). This set of simulations comprises galaxies evolved self-consistently across cosmic time with different baryonic sub-grid physics: three different star formation models [constant star formation efficiency (SFE) with different star formation eligibility criteria, and an environmentally-dependent, turbulence-based SFE] and two different feedback prescriptions, where only one sub-sample includes early stellar feedback. We use these simulations to assess the impact of different baryonic physics on the HI content of galaxies. We find that the galaxy-wide HI properties agree with each other and with observations. However, differences appear for small-scale properties. The thin HI discs observed in the local Universe are only reproduced with a turbulence-dependent SFE and/or early stellar feedback. Furthermore, we find that the morphology of HI discs is particularly sensitive to the different physics models: galaxies simulated with a turbulence-based SFE have discs that are smoother and more rotationally symmetric, compared to those simulated with a constant SFE; galaxies simulated with early stellar feedback have more regular discs than supernova-feedback-only galaxies. We find that the rotational asymmetry of the HI discs depends most strongly on the underlying physics model, making this a promising observable for understanding the physics responsible for shaping the interstellar medium of galaxies.
Comment: 13 pages, 10 figures + appendices (7 pages, 10 figures); updated to version accepted by MNRAS
Document Type: Working Paper
Access URL: http://arxiv.org/abs/2310.01482
Accession Number: edsarx.2310.01482
Database: arXiv
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