Astron. Astrophys. 355, 1122-1128 (2000)

Dust emission from star-forming regions

VI. The submillimetre YSO cluster in NGC 2264

D. Ward-Thompson ¹, R. Zylka ^2,3, P.G. Mezger ² and A.W. Sievers <sup>4

1</sup> Department of Physics & Astronomy, University of Wales Cardiff, P.O. Box 913, Cardiff, UK
² Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
³ Institut für Theoretische Astrophysik, Tiergartenstrasse 15, 69121 Heidelberg, Germany
⁴ IRAM, Avenida Divina Pastora 7, Nucleao Central, 18012 Granada, Spain

Received 13 August 1998 / Accepted 29 November 1999

Abstract

We present new submillimetre and millimetre continuum observations of NGC 2264, in the region of Allen's infra-red source IRS1, at 350, 450, 800 and 1300µm taken with the 15-m JCMT and the IRAM 30-m MRT. We observe a ridge of bright submillimetre and millimetre emission which we designate NGC 2264 MM. Within this ridge we have discovered a cluster of five submillimetre sources which we label NGC 2264 MMS1-5. The masses of the sources lie in the range 10-50 and each source has a FWHM of 0.1pc. The total mass of the ridge is 730.

We identify MMS3 as harbouring the driving source of a previously discovered bipolar outflow. We note that MMS5 is positionally coincident with a previously discovered HST near-ir source, but we conclude that this is a chance alignment, since typical extinction values within the ridge lie in the range A_V200-1600. The cluster which we have discovered is of higher mass and extends over a larger area than the low-mass sub-cluster discovered by the HST surrounding IRS1. Our continuum maps show a greater dynamic range than molecular spectral line maps, due to gas freezing out onto dust grains at the densities of these sources. We suggest that each of the sources MMS1-5 is forming one or more intermediate or high mass stars.

Key words: stars: formation ISM: dust, extinction Galaxy: open clusters and associations: individual: NGC 2264

SIMBAD Objects

Contents

• 1. Introduction
• 2. Observations and data reduction
• 3. Results
  • 3.1. Maps
  • 3.2. Source parameters
  • 3.3. Spectral energy distribution
• 4. Discussion
  • 4.1. Physical parameters
  • 4.2. Comparison with previous studies
  • 4.3. The nature of the sources
• 5. Summary
• Acknowledgements
• References

© European Southern Observatory (ESO) 2000

Online publication: March 21, 2000
helpdesk.link@springer.de