We study how feedback influences baryon infall onto galaxies using
cosmological, zoom-in simulations of haloes with present mass
$M_vir=6.9\times10^11 M_ødot$ to
$1.7\times10^12 M_ødot$. Starting at $z=4$ from identical initial
conditions, implementations of weak and strong stellar feedback produce bulge-
and disc-dominated galaxies, respectively. Strong feedback favours disc
formation: (1) because conversion of gas into stars is suppressed at early
times, as required by abundance matching arguments, resulting in flat star
formation histories and higher gas fractions; (2) because $50\%$ of the stars
form $in$ $situ$ from recycled disc gas with angular momentum only
weakly related to that of the $z=0$ dark halo; (3) because late-time gas
accretion is typically an order of magnitude stronger and has higher specific
angular momentum, with recycled gas dominating over primordial infall; (4)
because $25-30\%$ of the total accreted gas is ejected entirely before
$z\sim1$, removing primarily low angular momentum material which enriches the
nearby inter-galactic medium. Most recycled gas roughly conserves its angular
momentum, but material ejected for long times and to large radii can gain
significant angular momentum before re-accretion. These processes lower galaxy
formation efficiency in addition to promoting disc formation.
Description
[1403.6124] Why stellar feedback promotes disc formation in simulated galaxies
%0 Generic
%1 ubler2014stellar
%A Übler, Hannah
%A Naab, Thorsten
%A Oser, Ludwig
%A Aumer, Michael
%A Sales, Laura V.
%A White, Simon
%D 2014
%K disk feedback formation
%T Why stellar feedback promotes disc formation in simulated galaxies
%U http://arxiv.org/abs/1403.6124
%X We study how feedback influences baryon infall onto galaxies using
cosmological, zoom-in simulations of haloes with present mass
$M_vir=6.9\times10^11 M_ødot$ to
$1.7\times10^12 M_ødot$. Starting at $z=4$ from identical initial
conditions, implementations of weak and strong stellar feedback produce bulge-
and disc-dominated galaxies, respectively. Strong feedback favours disc
formation: (1) because conversion of gas into stars is suppressed at early
times, as required by abundance matching arguments, resulting in flat star
formation histories and higher gas fractions; (2) because $50\%$ of the stars
form $in$ $situ$ from recycled disc gas with angular momentum only
weakly related to that of the $z=0$ dark halo; (3) because late-time gas
accretion is typically an order of magnitude stronger and has higher specific
angular momentum, with recycled gas dominating over primordial infall; (4)
because $25-30\%$ of the total accreted gas is ejected entirely before
$z\sim1$, removing primarily low angular momentum material which enriches the
nearby inter-galactic medium. Most recycled gas roughly conserves its angular
momentum, but material ejected for long times and to large radii can gain
significant angular momentum before re-accretion. These processes lower galaxy
formation efficiency in addition to promoting disc formation.
@misc{ubler2014stellar,
abstract = {We study how feedback influences baryon infall onto galaxies using
cosmological, zoom-in simulations of haloes with present mass
$\mathrm{M}_{\mathrm{vir}}=6.9\times10^{11} \mathrm{M}_{\odot}$ to
$1.7\times10^{12} \mathrm{M}_{\odot}$. Starting at $z=4$ from identical initial
conditions, implementations of weak and strong stellar feedback produce bulge-
and disc-dominated galaxies, respectively. Strong feedback favours disc
formation: (1) because conversion of gas into stars is suppressed at early
times, as required by abundance matching arguments, resulting in flat star
formation histories and higher gas fractions; (2) because $50\%$ of the stars
form ${\it in}$ ${\it situ}$ from recycled disc gas with angular momentum only
weakly related to that of the $z=0$ dark halo; (3) because late-time gas
accretion is typically an order of magnitude stronger and has higher specific
angular momentum, with recycled gas dominating over primordial infall; (4)
because $25-30\%$ of the total accreted gas is ejected entirely before
$z\sim1$, removing primarily low angular momentum material which enriches the
nearby inter-galactic medium. Most recycled gas roughly conserves its angular
momentum, but material ejected for long times and to large radii can gain
significant angular momentum before re-accretion. These processes lower galaxy
formation efficiency in addition to promoting disc formation.},
added-at = {2014-03-26T09:53:46.000+0100},
author = {Übler, Hannah and Naab, Thorsten and Oser, Ludwig and Aumer, Michael and Sales, Laura V. and White, Simon},
biburl = {https://www.bibsonomy.org/bibtex/24cbd7193572e97d6c9bd2feebbbaf525/miki},
description = {[1403.6124] Why stellar feedback promotes disc formation in simulated galaxies},
interhash = {b9ce3fdafef57ec948bb0df9c2ccce8e},
intrahash = {4cbd7193572e97d6c9bd2feebbbaf525},
keywords = {disk feedback formation},
note = {cite arxiv:1403.6124Comment: submitted; comments are welcome},
timestamp = {2014-03-26T09:53:46.000+0100},
title = {Why stellar feedback promotes disc formation in simulated galaxies},
url = {http://arxiv.org/abs/1403.6124},
year = 2014
}