Letter to the Editor

Filamentary structures and compact objects in the Aquila and Polaris clouds observed by Herschel ^*,**

¹ Laboratoire AIM, CEA/DSM–CNRS–Université Paris Diderot, IRFU/Service d'Astrophysique, C.E. Saclay, Orme des Merisiers, 91191 Gif-sur-Yvette, France e-mail: alexander.menshchikov@cea.fr
² Institut d'Astrophysique Spatiale (CNRS), Université Paris-Sud, bât. 121, 91405 Orsay, France
³ Laboratoire d'Astrophysique de Marseille, CNRS/INSU-Université de Provence, 13388 Marseille Cedex 13, France
⁴ CESR, 9 Avenue du Colonel Roche, B.P. 4346, 31029 Toulouse, France
⁵ CDS, Observatoire de Strasbourg, 11, Rue de l'Université, 67000 Strasbourg, France
⁶ IRAM, 300 Rue de la Piscine, Domaine Universitaire, 38406 Saint-Martin-d'Héres, France
⁷ Herzberg Institute of Astrophysics, University of Victoria, Department of Physics and Astronomy, Victoria, Canada
⁸ INAF-IFSI, Fosso del Cavaliere 100, 00133 Roma, Italy
⁹ School of Physics and Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff CF24 3AA, UK
¹⁰ National Astronomical Observatories, Chinese Academy of Sciences, A20 Datun Road, Chaoyang District, Beijing 100012, PR China
¹¹ Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Street, Toronto, ON, M5S 3H8, Canada
¹² Department of Astronomy, Stockholm University, AlbaNova University Center, 10691 Stockholm, Sweden
¹³ Institut d'Astrophysique de Paris, UMR7095 CNRS, Université Pierre & Marie Curie, 98 bis Boulevard Arago, 75014 Paris, France
¹⁴ UK Astronomy Technology Centre, Royal Observatory Edinburgh, Blackford Hill, EH9 3HJ, UK
¹⁵ Istituto Nationale di Astrofisica, Largo Enrico Fermi 5, 50125 Firenze, Italy
¹⁶ The Rutherford Appleton Laboratory, Chilton, Didcot OX11 0NL, UK
¹⁷ Department of Physics & Astronomy, The Open University, Milton Keynes MK7 6AA, UK
¹⁸ Dept. of Physics & Astronomy, McMaster University, Hamilton, Ontario, L8S 4M1, Canada
¹⁹ UK Astronomy Technology Center, Royal Observatory Edinburgh, Edinburgh, EH9 3HJ, UK

Received: 31 March 2010
Accepted: 3 May 2010

Abstract

Our PACS and SPIRE images of the Aquila Rift and part of the Polaris Flare regions, taken during the science demonstration phase of Herschel discovered fascinating, omnipresent filamentary structures that appear to be physically related to compact cores. We briefly describe a new multi-scale, multi-wavelength source extraction method used to detect objects and measure their parameters in our Herschel images. All of the extracted starless cores (541 in Aquila and 302 in Polaris) appear to form in the long and very narrow filaments. With its combination of the far-IR resolution and sensitivity, Herschel directly reveals the filaments in which the dense cores are embedded; the filaments are resolved and have deconvolved widths of ~35” in Aquila and ~59” in Polaris (~9000 AU in both regions). Our first results of observations with Herschel enable us to suggest that in general dense cores may originate in a process of fragmentation of complex networks of long, thin filaments, likely formed as a result of an interplay between gravity, interstellar turbulence, and magnetic fields. To unravel the roles of the processes, one has to obtain additional kinematic and polarization information; these follow-up observations are planned.