Production of Cool Gas in Thermally Driven Outflows

Evan E. Schneider, Brant E Robertson, Todd A. Thompson

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

Galactic outflows commonly contain multiphase gas, and its physical origin requires explanation. Using the Cholla Galactic OutfLow Simulations suite of high-resolution isolated galaxy models, we demonstrate the viability of rapid radiative cooling as a source of fast-moving (v ∼ 1000 km s-1), cool (104 K) gas observed in absorption-line studies of outflows around some star-forming galaxies. By varying the mass loading and geometry of the simulated winds, we identify a region of parameter space that leads to cool gas in outflows. In particular, when using an analytically motivated central feedback model, we find that cooling flows can be produced with reasonable mass-loading rates (), provided that the star formation rate surface density is high. When a more realistic clustered feedback model is applied, destruction of high-density clouds near the disk and interactions between different outflow regions indicate that lower mass-loading rates of the hot gas within the feedback region may still produce multiphase outflows. These results suggest an origin for fast-moving cool gas in outflows that does not rely on directly accelerating cool gas from the interstellar medium. These cooling flows may additionally provide an explanation for the multiphase gas ubiquitously observed in the halos of star-forming galaxies at low redshift.

Original languageEnglish (US)
Article number56
JournalAstrophysical Journal
Volume862
Issue number1
DOIs
StatePublished - Jul 20 2018
Externally publishedYes

Fingerprint

outflow
gases
gas
loading rate
galaxies
cooling
stars
high temperature gases
star formation rate
viability
destruction
halos
high resolution
geometry
simulation
rate
interactions

Keywords

  • galaxies: evolution
  • galaxies: formation
  • galaxies: starburst

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Production of Cool Gas in Thermally Driven Outflows. / Schneider, Evan E.; Robertson, Brant E; Thompson, Todd A.

In: Astrophysical Journal, Vol. 862, No. 1, 56, 20.07.2018.

Research output: Contribution to journalArticle

Schneider, Evan E. ; Robertson, Brant E ; Thompson, Todd A. / Production of Cool Gas in Thermally Driven Outflows. In: Astrophysical Journal. 2018 ; Vol. 862, No. 1.
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