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Galactic winds in cosmological simulations of the circumgalactic medium
- Source :
- Monthly Notices of the Royal Astronomical Society
- Publication Year :
- 2013
-
Abstract
- (Abridged) We explore new observationally-constrained sub-resolution models of galactic outflows and investigate their impact on the circumgalactic medium (CGM) over redshifts z = 2 - 4. We perform cosmological hydrodynamic simulations, including star formation, chemical enrichment, and four cases of SNe-driven outflows: no wind (NW), an energy-driven constant velocity wind (CW), a radially varying wind (RVWa) where the outflow velocity has a positive correlation with galactocentric distance (r), and a RVW with additional dependence on halo mass (RVWb). Overall, we find that the outflows expel metal-enriched gas away from galaxies, significantly quench star formation, and enrich the CGM. At z = 2, the radial profiles of gas properties around galaxy centers are most sensitive to the choice of the wind model for halo masses (10^9 - 10^11) M_sun. We infer that the RVWb model is similar to the NW case, except that it substantially enriches the CGM: the carbon metallicity (Z_C) is 10 times higher in RVWb than in NW at r > R_200; and the warm gas of 10^4 - 10^5 K and delta < 100 is enriched to 50 times higher than in NW. We also find that the impact of models CW and RVWa are similar, with the following differences. RVWa causes a greater suppression of star formation rate at z < 5, and has a higher fraction of low-density (delta < 10), warm-hot (10^4 - 10^6 K) gas than in CW. Outflows in CW produce a higher and earlier enrichment of some IGM phases than RVWa. By visual inspection, we note that the RVWa model shows more pronounced bipolar outflows and galactic disks. We present fitting formulae for [Z_C-delta] and [Z_C-r], also for the abundance of CIV as a function of r. We predict observational diagnostics to distinguish between different outflow scenarios: Z_C of the CGM gas at r = (30 - 300) kpc/h comoving, and CIV fraction of the inner gas at r < (4 - 5) kpc/h comoving.<br />Version accepted for publication in MNRAS. Manuscript file with higher resolution Fig. 2 can be found here: http://adlibitum.oats.inaf.it/barai/AllPages/Images-Movies/RadialVarWind.pdf
- Subjects :
- Cosmology and Nongalactic Astrophysics (astro-ph.CO)
formation [galaxies]
Astrophysics::High Energy Astrophysical Phenomena
Metallicity
FOS: Physical sciences
Astrophysics::Cosmology and Extragalactic Astrophysics
Astrophysics
Positive correlation
01 natural sciences
methods: numerical
Wind model
Settore FIS/05 - Astronomia e Astrofisica
cosmology: theory
0103 physical sciences
galaxies: formation
Astrophysics::Solar and Stellar Astrophysics
010303 astronomy & astrophysics
Astrophysics::Galaxy Astrophysics
High Energy Astrophysical Phenomena (astro-ph.HE)
Physics
theory [cosmology]
010308 nuclear & particles physics
Star formation
Astronomy
numerical [methods]
Astronomy and Astrophysics
Astrophysics - Astrophysics of Galaxies
Galaxy
Redshift
intergalactic medium
13. Climate action
Space and Planetary Science
Astrophysics of Galaxies (astro-ph.GA)
Outflow
Halo
Astrophysics - High Energy Astrophysical Phenomena
Astrophysics - Cosmology and Nongalactic Astrophysics
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Journal :
- Monthly Notices of the Royal Astronomical Society
- Accession number :
- edsair.doi.dedup.....f37d7c82d9d96ee2bfba41a8f8f3026c