Submillimetre observations of galaxy clusters with the BLAST: the star formation activity in Abell 3112
Filiberto G. Braglia
(1)
,
Peter A. Ade
(2)
,
James J. Bock
(3)
,
Edward L. Chapin
(1)
,
Mark J. Devlin
(4)
,
Alastair C. Edge
(5)
,
Matthew J. Griffin
(2)
,
Joshua O. Gundersen
(6)
,
Mark Halpern
(1)
,
Peter C. Hargrave
(2)
,
David H. Hughes
(7)
,
Jeff Klein
(4)
,
Gaelen Marsden
(1)
,
Philip Mauskopf
(2)
,
Lorenzo Moncelsi
(2)
,
Calvin B. Netterfield
(8)
,
Henry Ngo
(1)
,
Luca Olmi
(9)
,
Enzo Pascale
(2)
,
Guillaume Patanchon
(10)
,
Kevin A. Pimbblet
(11)
,
Marie Rex
(12)
,
Douglas Scott
(1)
,
Christopher Semisch
(4)
,
Nicholas Thomas
(6)
,
Matthew D. P. Truch
(4)
,
Carol E. Tucker
(2)
,
Gregory S. Tucker
(13)
,
Elisabetta Valiante
(1)
,
Marco P. Viero
(14)
,
Donald V. Wiebe
(1)
1
University of British Columbia [Vancouver]
2 Cardiff University
3 JPL - Jet Propulsion Laboratory
4 Department of Physics and Astronomy, University of Pennsylvania
5 Department of Physics, University of Durham, South Road
6 Department of Physics, University of Miami
7 INAOE - Instituto Nacional de Astrofísica Óptica y Electrónica
8 Department of Astronomy and Astrophysics, University of Toronto
9 Physics Department, University of Puerto Rico
10 APC (UMR_7164) - AstroParticule et Cosmologie
11 School of Physics, Monash University
12 Steward Observatory, University of Arizona
13 Department of Physics, Brown University
14 Cahill Center for Astronomy and Astrophysics
2 Cardiff University
3 JPL - Jet Propulsion Laboratory
4 Department of Physics and Astronomy, University of Pennsylvania
5 Department of Physics, University of Durham, South Road
6 Department of Physics, University of Miami
7 INAOE - Instituto Nacional de Astrofísica Óptica y Electrónica
8 Department of Astronomy and Astrophysics, University of Toronto
9 Physics Department, University of Puerto Rico
10 APC (UMR_7164) - AstroParticule et Cosmologie
11 School of Physics, Monash University
12 Steward Observatory, University of Arizona
13 Department of Physics, Brown University
14 Cahill Center for Astronomy and Astrophysics
Résumé
We present observations at 250, 350 and 500 mum of the nearby galaxy cluster Abell 3112 (z= 0.075) carried out with the Balloon-borne Large Aperture Submillimeter Telescope. Five cluster members are individually detected as bright submillimetre (submm) sources. Their far-infrared spectral energy distributions and optical colours identify them as normal star-forming galaxies of high mass, with globally evolved stellar populations. They all have (B-R) colours of 1.38 ± 0.08, transitional between the blue, active population and the red, evolved galaxies that dominate the cluster core. We stack to estimate the mean submm emission from all cluster members, which is determined to be 16.6 ± 2.5, 6.1 ± 1.9 and 1.5 ± 1.3 mJy at 250, 350 and 500 mum, respectively. Stacking analyses of the submm emission of cluster members reveal trends in the mean far-infrared luminosity with respect to clustercentric radius and KS-band magnitude. We find that a large fraction of submm emission comes from the boundary of the inner, virialized region of the cluster, at clustercentric distances around R500. Stacking also shows that the bulk of the submm emission arises in intermediate-mass galaxies with KS magnitude ˜1 mag fainter than the characteristic magnitude ?. The results and constraints obtained in this work will provide a useful reference for the forthcoming surveys to be conducted on galaxy clusters by Herschel.