A Caltech Library Service

The impact of feedback on cosmological gas accretion

Nelson, Dylan and Genel, Shy and Vogelsberger, Mark and Springel, Volker and Sijacki, Debora and Torrey, Paul and Hernquist, Lars (2015) The impact of feedback on cosmological gas accretion. Monthly Notices of the Royal Astronomical Society, 448 (1). pp. 59-74. ISSN 0035-8711.

[img] PDF - Published Version
See Usage Policy.

PDF - Submitted Version
See Usage Policy.


Use this Persistent URL to link to this item:


We investigate how the way galaxies acquire their gas across cosmic time in cosmological hydrodynamic simulations is modified by a comprehensive physical model for baryonic feedback processes. To do so, we compare two simulations - with and without feedback - both evolved with the moving mesh code AREPO. The feedback runs implement the full physics model of the Illustris simulation project, including star formation driven galactic winds and energetic feedback from supermassive black-holes. We explore: (a) the accretion rate of material contributing to the net growth of galaxies and originating directly from the intergalactic medium, finding that feedback strongly suppresses the raw, as well as the net, in inflow of this "smooth mode" gas at all redshifts, regardless of the temperature history of newly acquired gas. (b) At the virial radius the temperature and radial flux of inflowing gas is largely unaffected at z =2. However, the spherical covering fraction of inflowing gas at 0.25 r_(vir) decreases substantially, from more than 80% to less than 50%, while the rates of both inflow and outflow increase, indicative of recycling across this boundary. (c) The fractional contribution of smooth accretion to the total accretion rate is lower in the simulation with feedback, by roughly a factor of two across all redshifts. Moreover, the smooth component of gas with a cold temperature history, is entirely suppressed in the feed-back run at z<1. (d) The amount of time taken by gas to cross from the virial radius to the galaxy - the "halo transit time" - increases in the presence of feedback by a factor of ≃ 2-3, and is notably independent of halo mass. We discuss the possible implications of this invariance for theoretical models of hot halo gas cooling.

Item Type:Article
Related URLs:
URLURL TypeDescription
Genel, Shy0000-0002-3185-1540
Vogelsberger, Mark0000-0001-8593-7692
Springel, Volker0000-0001-5976-4599
Torrey, Paul0000-0002-5653-0786
Hernquist, Lars0000-0001-6950-1629
Additional Information:© 2015 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. Accepted 2014 December 31. Received 2014 December 5; in original form 2014 October 21. First published online February 3, 2015. The computations presented in this paper were performed on the Odyssey cluster at Harvard University. VS acknowledges support by the European Research Council under ERC-StG grant EXAGAL-308037. LH acknowledges support from NASA grant NNX12AC67G and NSF grant AST-1312095. DN thanks the anonymous referee for many useful comments and suggestions.
Funding AgencyGrant Number
European Research Council (ERC)EXAGAL-308037
Subject Keywords:methods: numerical; galaxies: evolution; galaxies: formation; galaxies: haloes; cosmology: theory
Issue or Number:1
Record Number:CaltechAUTHORS:20141203-084633226
Persistent URL:
Official Citation:Dylan Nelson, Shy Genel, Mark Vogelsberger, Volker Springel, Debora Sijacki, Paul Torrey, and Lars Hernquist The impact of feedback on cosmological gas accretion MNRAS (March 21, 2015) Vol. 448 59-74 doi:10.1093/mnras/stv017 First published online February 3, 2015
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:52306
Deposited By: Ruth Sustaita
Deposited On:03 Dec 2014 17:59
Last Modified:09 Mar 2020 13:19

Repository Staff Only: item control page