Letter to the Editor

Small-scale structure in the Rosette molecular cloud revealed by Herschel ^*,**

¹ National Research Council of Canada, Herzberg Institute of Astrophysics, 5071 West Saanich Rd., Victoria, BC, V9E 2E7, Canada e-mail: james.difrancesco@nrc-cnrc.gc.ca
² University of Victoria, Department of Physics and Astronomy, PO Box 3055, STN CSC, Victoria, BC, V8W 3P6, Canada
³ Laboratoire AIM, CEA/IRFU – CNRS/INSU – Université Paris Diderot, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France
⁴ Laboratoire d'Astrophysique de Bordeaux, CNRS/INSU – Université de Bordeaux, BP 89, 33271 Floirac Cedex, France
⁵ Max-Planck-Institut für Astronomie, Königstuhl 17, 69117, Heidelberg, Germany
⁶ Laboratoire d'Astrophysique de Marseille, CNRS/INSU – Université de Provence, 13388 Marseille Cedex 13, France
⁷ INAF-IFSI, Fosso del Cavaliere 100, 00133 Roma, Italy
⁸ Cardiff University School of Physics and Astronomy, UK
⁹ IAS, Université Paris-Sud, 91435 Orsay, France
¹⁰ CESR & UMR 5187 du CNRS/Université de Toulouse, BP 4346, 31028 Toulouse Cedex 4, France
¹¹ IRAM, 300 rue de la Piscine, Domaine Universitaire, 38406 Saint Martin d'Héres, France
¹² National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, PR China
¹³ The Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 ONL, UK
¹⁴ Herschel Science Centre, ESAC, ESA, PO Box 78, Villanueva de la Cañada, 28691 Madrid, Spain
¹⁵ CITA & Department of Astronomy and Astrophysics, University of Toronto, 50 St. George St., Room 101, Toronto, ON, M5S 3H4, Canada
¹⁶ Department of Astronomy, Stockholm Observatory, AlbaNova University Center, Roslagstullsbacken 21, 10691 Stockholm, Sweden
¹⁷ INAF-IASF, Sez. di Roma, via Fosso del Cavaliere 100, 00133, Rome, Italy
¹⁸ UK Astronomy Technology Centre, Royal Observatory Edinburgh, Blackford Hill, EH9 3HJ, UK
¹⁹ ESO, Karl Schwarzchild Str. 2, 85748, Garching, Germany
²⁰ Department of Physics & Astronomy, The Open University, Milton Keynes MK7 6AA, UK
²¹ Department of Physics and Astronomy, ABB-241, McMaster University, 1280 Main St. W., Hamilton, ON, L8S 4M1, Canada

Received: 31 March 2010
Accepted: 7 May 2010

Abstract

We present a preliminary analysis of the small-scale structure found in new 70-520 μm continuum maps of the Rosette molecular cloud (RMC), obtained with the SPIRE and PACS instruments of the Herschel Space Observatory. We find 473 clumps within the RMC using a new structure identification algorithm, with sizes up to ~1.0 pc in diameter. A comparison with recent Spitzer maps reveals that 371 clumps are “starless” (without an associated young stellar object), while 102 are “protostellar.” Using the respective values of dust temperature, we determine the clumps have masses (M_C) over the range -0.75 ≤ log (M_C/) ≤ 2.50. Linear fits to the high-mass tails of the resulting clump mass spectra (CMS) have slopes that are consistent with those found for high-mass clumps identified in CO emission by other groups.