Letter to the Editor

The Herschel Lensing Survey (HLS): Overview ^*,**

E. Egami¹, M. Rex¹, T. D. Rawle¹, P. G. Pérez-González^2,1, J. Richard³, J.-P. Kneib⁴, D. Schaerer^5,6, B. Altieri⁷, I. Valtchanov⁷, A. W. Blain⁸, D. Fadda⁹, M. Zemcov^8,10, J. J. Bock^8,10, F. Boone^6,11, C. R. Bridge⁸, B. Clement⁴, F. Combes¹¹, M. Dessauges-Zavadsky⁵, C. D. Dowell^8,10, O. Ilbert⁴, R. J. Ivison^12,13, M. Jauzac⁴, D. Lutz¹⁴, L. Metcalfe⁷, A. Omont¹⁵, R. Pelló⁶, M. J. Pereira¹, G. H. Rieke¹, G. Rodighiero¹⁶, I. Smail³, G. P. Smith¹⁷, G. Tramoy⁴, G. L. Walth¹, P. van der Werf¹⁸ and M. W. Werner¹⁰

¹ Steward Observatory, University of Arizona, 933 N. Cherry Ave, Tucson, AZ 85721, USA e-mail: eegami@as.arizona.edu

² Herschel Science Centre, ESAC, ESA, PO Box 78, Villanueva de la Cañada, 28691 Madrid, Spain

³ California Institute of Technology, Pasadena, CA 91125, USA

⁴ Jet Propulsion Laboratory, Pasadena, CA 91109, USA

⁵ Laboratoire d'Astrophysique de Toulouse-Tarbes, Université de Toulouse, CNRS, 14 Av. Edouard Belin, 31400 Toulouse, France

⁶ Laboratoire d'Astrophysique de Marseille, CNRS - Université Aix-Marseille, 38 rue Frédéric Joliot-Curie, 13388 Marseille Cedex 13, France

⁷ Observatoire de Paris, LERMA, 61 Av. de l'Observatoire, 75014 Paris, France

⁸ Geneva Observatory, University of Geneva, 51, Ch. des Maillettes, 1290 Versoix, Switzerland

⁹ NASA Herschel Science Center, California Institute of Technology, MS 100-22, Pasadena, CA 91125, USA

¹⁰ UK Astronomy Technology Centre, Science and Technology Facilities Council, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK

¹¹ Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ, UK

¹² Max-Planck-Institut für extraterrestrische Physik, Postfach 1312, 85741 Garching, Germany

¹³ Institut d'Astrophysique de Paris, CNRS and Université Pierre et Marie Curie, 98bis Boulevard Arago, 75014 Paris, France

¹⁴ Departamento de Astrofísica, Facultad de CC. Físicas, Universidad Complutense de Madrid, 28040 Madrid, Spain

¹⁵ Institute for Computational Cosmology, Department of Physics, Durham University, South Road, Durham DH1 3LE, UK

¹⁶ Department of Astronomy, University of Padova, Vicolo dell'Osservatorio 3, 35122 Padova, Italy

¹⁷ School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK

¹⁸ Sterrewacht Leiden, Leiden University, PO Box 9513, 2300 RA Leiden, the Netherlands

Received: 1 April 2010
Accepted: 19 May 2010

Abstract

The Herschel Lensing Survey (HLS) will conduct deep PACS and SPIRE imaging of ~40 massive clusters of galaxies. The strong gravitational lensing power of these clusters will enable us to penetrate through the confusion noise, which sets the ultimate limit on our ability to probe the Universe with Herschel. Here we present an overview of our survey and a summary of the major results from our science demonstration phase (SDP) observations of the Bullet cluster (z = 0.297). The SDP data are rich and allow us to study not only the background high-redshift galaxies (e.g., strongly lensed and distorted galaxies at z = 2.8 and 3.2) but also the properties of cluster-member galaxies. Our preliminary analysis shows a great diversity of far-infrared/submillimeter spectral energy distributions (SEDs), indicating that we have much to learn with Herschel about the properties of galaxy SEDs. We have also detected the Sunyaev-Zel'dovich (SZ) effect increment with the SPIRE data. The success of this SDP program demonstrates the great potential of the Herschel Lensing Survey to produce exciting results in a variety of science areas.