Herschel-Astrophysical Terahertz Large Area Survey: detection of a far-infrared population around galaxy clusters

Coppin, K.E.K.; Geach, J.E.; Smail, I.; Dunne, L.; Edge, A.C.; Ivison, R.J.; Maddox, S.; Auld, R.; Baes, M.; Buttiglione, S.; Cava, A.; Clements, D.L.; Cooray, A.; Dariush, A.; de Zotti, G.; Dye, S.; Eales, S.; Fritz, J.; Hopwood, R.; Ibar, E.; Jarvis, M.; Michałowski, M.J.; Murphy, D.N.A.; Negrello, M.; Pascale, E.; Pohlen, M.; Rigby, E.; Rodighiero, G.; Scott, D.; Serjeant, S.; Smith, D.J.B.; Temi, P.; van der Werf, P.

Abstract

We report the detection of a significant excess in the surface density of far-infrared sources from the Herschel-Astrophysical Terahertz Large Area Survey within ∼1 Mpc of the centres of 66 optically selected clusters of galaxies in the Sloan Digital Sky Survey with 〈z〉∼ 0.25. From the analysis of the multiwavelength properties of their counterparts we conclude that the far-infrared emission is associated with dust-obscured star formation and/or active galactic nuclei (AGN) within galaxies in the clusters themselves. The excess reaches a maximum at a radius of ∼0.8 Mpc, where we find 1.0 ± 0.3 S250 > 34 mJy sources on average per cluster above what would be expected for random field locations. If the far-infrared emission is dominated by star formation (as opposed to AGN) then this corresponds to an average star formation rate of ∼7 M⊙ yr−1 per cluster in sources with LIR > 5 × 1010 L⊙. Although lensed sources make a negligible contribution to the excess signal, a fraction of the sources around the clusters could be gravitationally lensed, and we have identified a sample of potential cases of cluster-lensed Herschel sources that could be targeted in follow-up studies.

Citation

Coppin, K., Geach, J., Smail, I., Dunne, L., Edge, A., Ivison, R., …van der Werf, P. (2011). Herschel-Astrophysical Terahertz Large Area Survey: detection of a far-infrared population around galaxy clusters. Monthly Notices of the Royal Astronomical Society, 416(1), 680-688. https://doi.org/10.1111/j.1365-2966.2011.19084.x

• Journal Article Type: Article
• Publication Date: Sep 1, 2011
• Deposit Date: Jan 30, 2012
• Publicly Available Date: Aug 21, 2013
• 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: 416
• Issue: 1
• Pages: 680-688
• DOI: https://doi.org/10.1111/j.1365-2966.2011.19084.x
• Keywords: Gravitational lensing, Galaxies, Clusters, Starburst.