Letter to the Editor

Herschel-ATLAS: The angular correlation function of submillimetre galaxies at high and low redshift^*

¹ School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD, UK e-mail: steve.maddox@nottingham.ac.uk
² School of Physics and Astronomy, Cardiff University, The Parade, Cardiff, CF24 3AA, UK
³ Dept. of Physics & Astronomy, University of California, Irvine, CA 92697, USA
⁴ University of British Colombia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada
⁵ SUPA, Institute for Astronomy, University of Edinburgh, Royal Observatory Edinburgh, Edinburgh, EH9 3HJ, UK
⁶ Dept. of Physics and Astronomy, The Open University, Milton Keynes, MK7 6AA, UK
⁷ Astrophysics Branch, NASA Ames Research Center, Mail Stop 245-6, Moffett Field, CA 94035, USA
⁸ Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, 9000 Gent, Belgium
⁹ Centre for Astrophysics Research, Science and Technology Research Centre, University of Hertfordshire, Herts AL10 9AB, UK
¹⁰ Laboratoire d'Astrophysique de Marseille, UMR6110 CNRS, 38 Rue F. Joliot-Curie, 13388 Marseille, France
¹¹ University of Padova, Department of Astronomy, Vicolo Osservatorio 3, 35122 Padova, Italy
¹² Instituto de Astrofísica de Canarias, C/Vía Láctea s/n, 38200 La Laguna, Spain
¹³ Departamento de Astrofísica, Universidad de La Laguna (ULL), 38205 La Laguna, Tenerife, Spain
¹⁴ Astrophysics Group, Imperial College, Blackett Laboratory, Prince Consort Road, London SW7 2AZ, UK
¹⁵ Infrared Processing and Analysis Center, California Institute of Technology, 770 South Wilson Av, Pasadena, CA 91125, USA
¹⁶ Scuola Internazionale Superiore di Studi Avanzati, via Beirut 2–4, 34151 Triest, Italy
¹⁷ Instituto de Física de Cantabria (CSIC-UC), Santander, 39005, Spain
¹⁸ UK Astronomy Technology Center, Royal Observatory Edinburgh, Edinburgh, EH9 3HJ, UK
¹⁹ Institut d'Astrophysique Spatiale (IAS), Bâtiment 121, 91405 Orsay, France; and Université Paris-Sud 11 and CNRS (UMR 8617), France
²⁰ Oxford Astrophysics, Denys Wilkinson Building, University of Oxford, Keble Road, Oxford, OX1 3RH, UK

Received: 31 March 2010
Accepted: 11 May 2010

Abstract

We present measurements of the angular correlation function of galaxies selected from the first field of the H-ATLAS survey. Careful removal of the background from galactic cirrus is essential, and currently dominates the uncertainty in our measurements. For our 250 μm-selected sample we detect no significant clustering, consistent with the expectation that the 250 μm-selected sources are mostly normal galaxies at z 1. For our 350 μm and 500 μm-selected samples we detect relatively strong clustering with correlation amplitudes A of 0.2 and 1.2 at 1', but with relatively large uncertainties. For samples which preferentially select high redshift galaxies at z~2–3 we detect significant strong clustering, leading to an estimate of r₀ ~ 7–11 h^-1 Mpc. The slope of our clustering measurements is very steep, δ ~ 2. The measurements are consistent with the idea that sub-mm sources consist of a low redshift population of normal galaxies and a high redshift population of highly clustered star-bursting galaxies.