English

Galactic outflow and diffuse gas properties at z>=1 using different baryonic feedback models

Astrophysics of Galaxies 2015-06-23 v1 Cosmology and Nongalactic Astrophysics High Energy Astrophysical Phenomena

Abstract

We measure and quantify properties of galactic outflows and diffuse gas at z1z \geq 1 in cosmological hydrodynamical simulations. Our novel sub-resolution model, MUPPI, implements supernova feedback using fully local gas properties, where the wind velocity and mass loading are not given as input. We find the following trends at z=2z = 2 by analysing central galaxies having a stellar mass higher than 109M10^{9} M_{\odot}. The outflow velocity and mass outflow rate (M˙out\dot{M}_{\rm out}) exhibit positive correlations with galaxy mass and with the star formation rate (SFR). However, most of the relations present a large scatter. The outflow mass loading factor (η\eta) is between 0.2100.2 - 10. The comparison Effective model generates a constant outflow velocity, and a negative correlation of η\eta with halo mass. The number fraction of galaxies where outflow is detected decreases at lower redshifts, but remains more than 80%80 \% over z=15z = 1 - 5. High SF activity at z24z \sim 2 - 4 drives strong outflows, causing the positive and steep correlations of velocity and M˙out\dot{M}_{\rm out} with SFR. The outflow velocity correlation with SFR becomes flatter at z=1z = 1, and η\eta displays a negative correlation with halo mass in massive galaxies. Our study demonstrates that both the MUPPI and Effective models produce significant outflows at 1/10\sim 1 / 10 of the virial radius; at the same time shows that the properties of outflows generated can be different from the input speed and mass loading in the Effective model. Our MUPPI model, using local properties of gas in the sub-resolution recipe, is able to develop galactic outflows whose properties correlate with global galaxy properties, and consistent with observations.

Keywords

Cite

@article{arxiv.1411.1409,
  title  = {Galactic outflow and diffuse gas properties at z>=1 using different baryonic feedback models},
  author = {Paramita Barai and Pierluigi Monaco and Giuseppe Murante and Antonio Ragagnin and Matteo Viel},
  journal= {arXiv preprint arXiv:1411.1409},
  year   = {2015}
}

Comments

23 pages, 16 figures, accepted for publication in MNRAS

R2 v1 2026-06-22T06:49:25.695Z