%0 Generic %1 fielding2016impact %A Fielding, Drummond %A Quataert, Eliot %A McCourt, Michael %A Thompson, Todd A. %D 2016 %K cgm gas phases simulation temperature %T The Impact of Star Formation Feedback on the Circumgalactic Medium %U http://arxiv.org/abs/1606.06734 %X We use idealized three-dimensional hydrodynamic simulations to study the dynamics and thermal structure of the circumgalactic medium (CGM). Our simulations quantify the role of cooling, galactic winds driven by stellar feedback, and cosmological gas accretion in setting the properties of the CGM in dark matter haloes ranging from $10^11-10^12$ M$_ødot$. Our simulations support a conceptual picture in which the CGM properties, and the key physics governing it, change markedly with halo mass near $10^11.5$ M$_ødot$. As in calculations without feedback, we find that above a critical halo mass of $\sim10^11.5$ M$_ødot$ the halo gas is supported by thermal pressure created in the virial shock. The thermal properties of the halo gas at small radii are regulated by feedback triggered when $t_cool/t_ffłesssim10$ in the hot halo gas. Below the critical halo mass there is no thermally supported halo and self-regulation at $t_cool/t_ff\sim10$ does not apply. Instead, the halo gas properties are determined by the interaction between cosmological gas inflow and outflowing galactic winds. The halo gas is not in hydrostatic equilibrium, but is largely supported against gravity by bulk flows (turbulence and coherent inflow/outflow). Its phase structure depends sensitively on both the energy per unit mass and the mass-loading factor of the galaxy outflows. This sensitivity may allow measurements of the thermal state of the CGM in lower mass haloes to constrain the nature of galactic wind feedback. Our idealized simulations can account for some of the properties of the multiphase halo gas inferred from quasar absorption line observations, including the presence of significant mass at a wide range of temperatures, and the characteristic OVI and CIV column densities and kinematics. However, we under-predict the neutral hydrogen content of the $z\sim0$ CGM.

@misc{fielding2016impact, abstract = {We use idealized three-dimensional hydrodynamic simulations to study the dynamics and thermal structure of the circumgalactic medium (CGM). Our simulations quantify the role of cooling, galactic winds driven by stellar feedback, and cosmological gas accretion in setting the properties of the CGM in dark matter haloes ranging from $10^{11}-10^{12}$ M$_\odot$. Our simulations support a conceptual picture in which the CGM properties, and the key physics governing it, change markedly with halo mass near $10^{11.5}$ M$_\odot$. As in calculations without feedback, we find that above a critical halo mass of $\sim10^{11.5}$ M$_\odot$ the halo gas is supported by thermal pressure created in the virial shock. The thermal properties of the halo gas at small radii are regulated by feedback triggered when $t_{\rm cool}/t_{\rm ff}\lesssim10$ in the hot halo gas. Below the critical halo mass there is no thermally supported halo and self-regulation at $t_{\rm cool}/t_{\rm ff}\sim10$ does not apply. Instead, the halo gas properties are determined by the interaction between cosmological gas inflow and outflowing galactic winds. The halo gas is not in hydrostatic equilibrium, but is largely supported against gravity by bulk flows (turbulence and coherent inflow/outflow). Its phase structure depends sensitively on both the energy per unit mass and the mass-loading factor of the galaxy outflows. This sensitivity may allow measurements of the thermal state of the CGM in lower mass haloes to constrain the nature of galactic wind feedback. Our idealized simulations can account for some of the properties of the multiphase halo gas inferred from quasar absorption line observations, including the presence of significant mass at a wide range of temperatures, and the characteristic OVI and CIV column densities and kinematics. However, we under-predict the neutral hydrogen content of the $z\sim0$ CGM.}, added-at = {2016-06-23T09:21:52.000+0200}, author = {Fielding, Drummond and Quataert, Eliot and McCourt, Michael and Thompson, Todd A.}, biburl = {https://www.bibsonomy.org/bibtex/24ff97f75dd0cb9dc122d448e3b69f061/miki}, description = {The Impact of Star Formation Feedback on the Circumgalactic Medium}, interhash = {4ec43cd0be8121cc7f77b834966652ef}, intrahash = {4ff97f75dd0cb9dc122d448e3b69f061}, keywords = {cgm gas phases simulation temperature}, note = {cite arxiv:1606.06734Comment: submitted to MNRAS, 18 pages, 18 figures, comments welcome}, timestamp = {2016-06-23T09:21:52.000+0200}, title = {The Impact of Star Formation Feedback on the Circumgalactic Medium}, url = {http://arxiv.org/abs/1606.06734}, year = 2016 }