The AGN fraction of submm-selected galaxies and contributions to the submm/mm-wave extragalactic background light

¹ Department of Physics & Astronomy, The Open University, Milton Keynes MK7 6BJ, UK
² Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX, UK
³ Department of Physics, University of Lethbridge, 4401 University Drive, Lethbridge, Alberta T1J 1B1, Canada
⁴ Astrophysics Group, Dept. of Physics, Imperial College London, Prince Consort Road, London SW7 2BW, UK
⁵ Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, CO80309, USA
⁶ Instituto Nacional de Astrofísica, Optica y Electrónica (INAOE), Tonantzintla, Puebla, México
⁷ Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK
⁸ Cardiff University, School of Physics & Astronomy, Queens Buildings, The Parade, Cardiff CF24 3AA, UK
⁹ Scottish Universities Physics Alliance (SUPA), Institute for Astronomy, The University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK
¹⁰ School of Physics & Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
¹¹ Astronomy Centre, University of Sussex, Falmer, Brighton BN1 9QH, UK
¹² Department of Physics and Astronomy, Seoul National University, Shillim-Dong, Kwanak-Gu Seoul 151-742, South Korea
¹³ Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, Kanagawa 229 8510, Japan
¹⁴ UK Astronomy Technology Centre, Royal Observatory, Edinburgh EH9 3HJ, UK
¹⁵ Space Science Divison, KASI, 61-1, Whaam-dong, Yuseong-gu, Deajeon 305-348, South Korea
¹⁶ Astronomy & Space Science Department, Sejong University, 143-747 Seoul, South Korea
¹⁷ Department of Astronomy, University of Massachusetts, Amherst, MA01003, USA
¹⁸ Department of Astronomy, University of Padova, vic. Osservatorio 2, 35122 Padova, Italy

Received: 15 October 2009
Accepted: 18 February 2010

Abstract

We present a comparison of the SCUBA half degree extragalactic survey (SHADES) at 450 μm, 850 μm and 1100 μm with deep guaranteed time 15 μm AKARI FU-HYU survey data and Spitzer guaranteed time data at 3.6-24 μm in the Lockman hole east. The AKARI data was analysed using bespoke software based in part on the drizzling and minimum-variance matched filtering developed for SHADES, and was cross-calibrated against ISO fluxes. Our stacking analyses find AKARI 15 μm galaxies with 200 μJy contribute >10% of the 450 μm background, but only <4% of the 1100 μm background, suggesting that different populations contribute at mm-wavelengths. We confirm our earlier result that the ultra-deep 450 μm SCUBA-2 cosmology survey will be dominated by populations already detected by AKARI and Spitzer mid-infrared surveys. The superb mid-infrared wavelength coverage afforded by combining Spitzer and AKARI photometry is an excellent diagnostic of AGN contributions, and we find that (23-52)% of submm-selected galaxies have AGN bolometric fractions f_AGN > 0.3.