A SCUBA survey of the NGC 2068/2071 protoclusters ^*

¹ Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
² CEA/DSM/DAPNIA, Service d'Astrophysique, CE Saclay, 91191 Gif-sur-Yvette Cedex, France
³ Department of Physics & Astronomy, University of Cardiff, PO Box 913, Cardiff, UK
⁴ Observatoire de Bordeaux, BP 89, 33270 Floirac, France

Corresponding author: F. Motte or P. André, motte@submm.caltech.edu; pandre@cea.fr

Received: 18 January 2001
Accepted: 11 April 2001

Abstract

We report the results of a submillimeter dust continuum survey of the protoclusters NGC 2068 and NGC 2071 in Orion B carried out at m and m with SCUBA on JCMT. The mapped region is ~ in size (~4 pc 2 pc) and consists of filamentary dense cores which break up into small-scale (~5 000 AU) fragments, including 70 starless condensations and 5 circumstellar envelopes/disks. The starless condensations, seen on the same spatial scales as protostellar envelopes, are likely to be gravitationally bound and pre-stellar in nature. Their mass spectrum, ranging from ~0.3 to ~5 , is reminiscent of the stellar initial mass function (IMF). Their mass-size relation suggests that they originate from gravitationally-driven fragmentation. We thus argue that pre-collapse cloud fragmentation plays a major role in shaping the IMF.