Astronomy and Astrophysics, volume 355, 1122-1128 (2000/3-3)
Dust emission from star-forming regions. VI. The submillimetre YSO cluster in NGC 2264.
WARD-THOMPSON D., ZYLKA R., MEZGER P.G. and SIEVERS A.W.
Abstract (from CDS):
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 2264MM. Within this ridge we have discovered a cluster of five submillimetre sources which we label NGC 2264MMS1-5. The masses of the sources lie in the range ∼10-50M☉ and each source has a FWHM of ≤0.1pc. The total mass of the ridge is ∼730M☉. 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 AV∼200-1600. 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.
stars: formation - ISM: dust, extinction - Galaxy: open clusters and associations: individual: NGC 2264