Dense Clumps in the L:1630 Molecular Cloud - Physical Structure and Properties
Abstract
This paper reports observations of six out of 42 interstellar molecular cloud cores identified by the CS survey of L1630 by Lada, Bally & Stark. High-resolution ( arcsec) maps in J=3→3, 4→3 HCO+ and 5→4 CS identify at least 22 emission maxima, 14 of which are associated with two of the former cores. Lower resolution (60 arcsec) maps of the J= HCO+ emission show little or no evidence for the structure seen in the higher-J maps. Three of the six cores are significantly elongated - we conclude that they are probably filaments rather than fragmented discs or rings seen edge-on.
Most of the maxima are unresolved in a arcsec beam; therefore most of the virial mass estimates are upper limits. Those that are not suggest clump masses of a few Msun. Masses derived from dust continuum observations in one of the cores (number 23) are in good agreement with the virial masses. LVG analysis has been applied to a two-component model of the cores in which the 1→0 HCO+ emission traces a low-density (104 cm-3) envelope while the3→2 and 4→3 and HCO+ lines trace the higher-density clumps (106 cm-3). These clumps are excellent candidates for low-mass protostellar activity.- Publication:
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Monthly Notices of the Royal Astronomical Society
- Pub Date:
- November 1995
- DOI:
- 10.1093/mnras/277.1.341
- Bibcode:
- 1995MNRAS.277..341G
- Keywords:
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- ISM: clouds - ISM: individual: Lynds 1630 - ISM: molecules - ISM: structure - radio lines: ISM