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On the role of feedback in shaping the cosmic abundance and clustering of neutral atomic hydrogen in galaxies

Kim, H.-S.; Power, C.; Baugh, C.M.; Wyithe, J.S.B.; Lacey, C.G.; Lagos, C.D.P.; Frenk, C.S.

On the role of feedback in shaping the cosmic abundance and clustering of neutral atomic hydrogen in galaxies Thumbnail


H.-S. Kim

C. Power

J.S.B. Wyithe

C.D.P. Lagos


We investigate the impact of feedback – from supernovae (SNe), active galactic nuclei (AGN) and a photoionizing background at high redshifts – on the neutral atomic hydrogen (H I) mass function, the bJ-band luminosity function, and the spatial clustering of these galaxies at z = 0. We use a version of the semi-analytical galaxy formation model GALFORM that calculates self-consistently the amount of H I in a galaxy as a function of cosmic time and links its star formation rate to its mass of molecular hydrogen (H2). We find that a systematic increase or decrease in the strength of SN feedback leads to a systematic decrease or increase in the amplitudes of the luminosity and H I mass functions, but has little influence on their overall shapes. Varying the strength of AGN feedback influences only the numbers of the brightest or most H I massive galaxies, while the impact of varying the strength of photoionization feedback is restricted to changing the numbers of the faintest or least H I massive galaxies. Our results suggest that the H I mass function is a more sensitive probe of the consequences of cosmological reionization for galaxy formation than the luminosity function. We find that increasing the strength of any of the modes of feedback acts to weaken the clustering strength of galaxies, regardless of their H I richness. In contrast, weaker AGN feedback has little effect on the clustering strength, whereas weaker SN feedback increases the clustering strength of H I-poor galaxies more strongly than H I-rich galaxies. These results indicate that forthcoming H I surveys on next-generation radio telescopes such as the Square Kilometre Array and its pathfinders will be exploited most fruitfully as part of multiwavelength survey campaigns.


Kim, H., Power, C., Baugh, C., Wyithe, J., Lacey, C., Lagos, C., & Frenk, C. (2013). On the role of feedback in shaping the cosmic abundance and clustering of neutral atomic hydrogen in galaxies. Monthly Notices of the Royal Astronomical Society, 428(4), 3366-3374.

Journal Article Type Article
Publication Date Feb 1, 2013
Deposit Date Mar 27, 2013
Publicly Available Date Jun 27, 2014
Journal Monthly Notices of the Royal Astronomical Society
Print ISSN 0035-8711
Electronic ISSN 1365-2966
Publisher Royal Astronomical Society
Peer Reviewed Peer Reviewed
Volume 428
Issue 4
Pages 3366-3374
Keywords Galaxies: formation, Galaxies: luminosity function, Mass function, Large-scale structure of Universe, Radio lines: galaxies.


Published Journal Article (468 Kb)

Copyright Statement
This article has been accepted for publication in Monthly notices of the Royal Astronomical Society © 2013 The Authors Published by Oxford University Press on behalf of Royal Astronomical Society. All rights reserved.

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