Journal Article

The <i>XMM</i> Cluster Survey: the interplay between the brightest cluster galaxy and the intracluster medium via AGN feedback

John P. Stott, Ryan C. Hickox, Alastair C. Edge, Chris A. Collins, Matt Hilton, Craig D. Harrison, A. Kathy Romer, Philip J. Rooney, Scott T. Kay, Christopher J. Miller, Martin Sahlén, Ed J. Lloyd-Davies, Nicola Mehrtens, Ben Hoyle, Andrew R. Liddle, Pedro T. P. Viana, Ian G. McCarthy, Joop Schaye and C. M. Booth

in Monthly Notices of the Royal Astronomical Society

Published on behalf of The Royal Astronomical Society

Volume 422, issue 3, pages 2213-2229
Published in print May 2012 | ISSN: 0035-8711
Published online May 2012 | e-ISSN: 1365-2966 | DOI: http://dx.doi.org/10.1111/j.1365-2966.2012.20764.x
The XMM Cluster Survey: the interplay between the brightest cluster galaxy and the intracluster medium via AGN feedback

Show Summary Details

Preview

Using a sample of 123 X-ray clusters and groups drawn from the XMM Cluster Survey first data release, we investigate the interplay between the brightest cluster galaxy (BCG), its black hole and the intracluster/group medium (ICM). It appears that for groups and clusters with a BCG likely to host significant active galactic nuclei (AGN) feedback, gas cooling dominates in those with TX > 2 keV while AGN feedback dominates below. This may be understood through the subunity exponent found in the scaling relation we derive between the BCG mass and cluster mass over the halo mass range 1013 < M500 < 1015 M and the lack of correlation between radio luminosity and cluster mass, such that BCG AGN in groups can have relatively more energetic influence on the ICM. The LXTX relation for systems with the most massive BCGs, or those with BCGs co-located with the peak of the ICM emission, is steeper than that for those with the least massive and most offset, which instead follows self-similarity. This is evidence that a combination of central gas cooling and powerful, well fuelled AGN causes the departure of the ICM from pure gravitational heating, with the steepened relation crossing self-similarity at TX= 2 keV. Importantly, regardless of their black hole mass, BCGs are more likely to host radio-loud AGN if they are in a massive cluster (TX≳ 2 keV) and again co-located with an effective fuel supply of dense, cooling gas. This demonstrates that the most massive black holes appear to know more about their host cluster than they do about their host galaxy. The results lead us to propose a physically motivated, empirical definition of ‘cluster’ and ‘group’, delineated at 2 keV.

Keywords: galaxies: active; galaxies: clusters: intracluster medium; galaxies: elliptical and lenticular, cD

Journal Article.  13482 words.  Illustrated.

Subjects: Astronomy and Astrophysics

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.