A New Model For Including Galactic Winds in Simulations of Galaxy Formation II: Implementation of PhEW in Cosmological Simulations

Shuiyao Huang*, Neal Katz, J'Neil Cottle, Evan Scannapieco, Romeel Davé, David H. Weinberg

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract / Description of output

Although galactic winds play a critical role in regulating galaxy formation, hydrodynamic cosmological simulations do not resolve the scales that govern the interaction between winds and the ambient circumgalactic medium (CGM). We implement the Physically Evolved Wind (PhEW) model of Huang et al. in the gizmo hydrodynamics code and perform test cosmological simulations with different choices of model parameters and numerical resolution. PhEW adopts an explicit subgrid model that treats each wind particle as a collection of clouds that exchange mass and metals with their surroundings and evaporate by conduction and hydrodynamic instabilities as calibrated on much higher resolution cloud scale simulations. In contrast to a conventional wind algorithm, we find that PhEW results are robust to numerical resolution and implementation details because the small scale interactions are defined by the model itself. Compared to our previous wind simulations with the same resolution, our PhEW simulations are in better agreement with low-redshift galactic stellar mass functions at M* < 1011M because PhEW particles shed mass to the CGM before escaping low mass haloes. PhEW radically alters the CGM metal distribution because PhEW particles disperse metals to the ambient medium as their clouds dissipate, producing a CGM metallicity distribution that is skewed but unimodal and is similar between cold and hot gas. While the temperature distributions and radial profiles of gaseous haloes are similar in simulations with PhEW and conventional winds, these changes in metal distribution will affect their predicted UV/X-ray properties in absorption and emission.
Original languageEnglish
Pages (from-to)6091-6110
Number of pages20
JournalMonthly Notices of the Royal Astronomical Society
Issue number4
Early online date25 Nov 2021
Publication statusPublished - 1 Feb 2022

Keywords / Materials (for Non-textual outputs)

  • galaxies: evolution
  • hydrodynamics
  • methods: numerical


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