The faint end of the 250 μm luminosity function at z < 0.5

¹ SRON Netherlands Institute for Space Research, Landleven 12, 9747 AD Groningen, The Netherlands
e-mail: l.wang@sron.nl
² Kapteyn Astronomical Institute, University of Groningen, Postbus 800, 9700 AV Groningen, The Netherlands
³ ICC & CEA, Department of Physics, Durham University, Durham, DH1 3LE, UK
⁴ European Southern Observatory, Karl Schwarzschild Straße 2, 85748 Garching, Germany
⁵ Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh EH9 3HJ, UK
⁶ Center for Cosmology, Department of Physics and Astronomy, University of California, Irvine, CA 92697, USA
⁷ School of Physics and Astronomy, Cardiff University, The Parade, Cardiff CF24 3AA, UK
⁸ School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
⁹ Department of Physics, Virginia Tech, Blacksburg, VA 24061, USA
¹⁰ Astronomy Centre, University of Sussex, Falmer, Brighton BN1 9QH, UK
¹¹ Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, 382 via Pueblo Mall, Stanford, CA 94305, USA

Received: 8 June 2016
Accepted: 1 July 2016

Abstract

Aims. We aim to study the 250 μm luminosity function (LF) down to much fainter luminosities than achieved by previous efforts.

Methods. We developed a modified stacking method to reconstruct the 250 μm LF using optically selected galaxies from the SDSS survey and Herschel maps of the GAMA equatorial fields and Stripe 82. Our stacking method not only recovers the mean 250 μm luminosities of galaxies that are too faint to be individually detected, but also their underlying distribution functions.

Results. We find very good agreement with previous measurements in the overlapping luminosity range. More importantly, we are able to derive the LF down to much fainter luminosities (~ 25 times fainter) than achieved by previous studies. We find strong positive luminosity evolution L^*₂₅₀(z)∝(1+z)^4.89±1.07 and moderate negative density evolution Φ^*₂₅₀(z)∝(1+z)^-1.02±0.54 over the redshift range 0.02 <z< 0.5.