Letter to the Editor

From filamentary clouds to prestellar cores to the stellar IMF: Initial highlights from the Herschel Gould Belt Survey^*,**

¹ Laboratoire AIM, CEA/DSM–CNRS–Université Paris Diderot, IRFU/Service d'Astrophysique, CEA Saclay, 91191 Gif-sur-Yvette, France e-mail: pandre@cea.fr
² INAF - Istituto Fisica Spazio Interplanetario, via Fosso del Cavaliere 100, 00133 Roma, Italy
³ School of Physics and Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff CF243AA, UK
⁴ National Research Council of Canada, Herzberg Institute of Astrophysics, Victoria, BC, V9E 2E7, Canada
⁵ Space Science and Technology Department, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX, UK
⁶ Department of Physics & Astronomy, The Open University, Milton Keynes MK7 6AA, UK
⁷ INAF, Osservatorio Astrofisico di Arcetri, Firenze, Italy
⁸ Institut d'Astrophysique Spatiale, CNRS/Université Paris-Sud 11, 91405 Orsay, France
⁹ Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
¹⁰ Instituut voor Sterrenkunde, K.U. Leuven, Celestijnenlaan 200D, 3001 Leuven, Belgium
¹¹ Herschel Science Centre, ESAC, ESA, PO Box 78, Villanueva de la Cañada, 28691 Madrid, Spain
¹² Dept. of Physics & Astronomy, McMaster University, Hamilton, Ontario, L8S 4M1, Canada
¹³ Laboratoire d'Astrophysique de Marseille, CNRS/INSU - Université de Provence, 13388 Marseille Cedex 13, France
¹⁴ CESR, Observatoire Midi-Pyrénées (CNRS-UPS), Université de Toulouse, BP 44346, 31028 Toulouse Cedex 04, France
¹⁵ CDS, Observatoire de Strasbourg, 11, rue de l'Université, 67000 Strasbourg, France
¹⁶ IRAM, 300 rue de la Piscine, Domaine Universitaire, 38406 Saint Martin d'Hères, France
¹⁷ National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, PR China
¹⁸ Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Street, Toronto, ONM5S3H8, Canada
¹⁹ Stockholm Observatory, AlbaNova University Center, Roslagstullsbacken 21, 106 91 Stockholm, Sweden
²⁰ Institut d'Astrophysique de Paris, Université Pierre & Marie Curie, 98 bis Boulevard Arago, 75014 Paris, France
²¹ ESA/ESTEC, PO Box 299, 2200 AG Noordwijk, The Netherlands
²² UK Astronomy Technology Centre, Royal Observatory Edinburgh, Blackford Hill, EH9 3HJ, UK

Received: 31 March 2010
Accepted: 4 May 2010

Abstract

We summarize the first results from the Gould Belt Survey, obtained toward the Aquila rift and Polaris Flare regions during the science demonstration phase of Herschel. Our 70–500 μm images taken in parallel mode with the SPIRE and PACS cameras reveal a wealth of filamentary structure, as well as numerous dense cores embedded in the filaments. Between ~350 and 500 prestellar cores and ~45–60 Class 0 protostars can be identified in the Aquila field, while ~300 unbound starless cores and no protostars are observed in the Polaris field. The prestellar core mass function (CMF) derived for the Aquila region bears a strong resemblance to the stellar initial mass function (IMF), already confirming the close connection between the CMF and the IMF with much better statistics than earlier studies. Comparing and contrasting our Herschel results in Aquila and Polaris, we propose an observationally-driven scenario for core formation according to which complex networks of long, thin filaments form first within molecular clouds, and then the densest filaments fragment into a number of prestellar cores via gravitational instability.