THE JCMT GOULD BELT SURVEY: A FIRST LOOK AT DENSE CORES IN ORION B

• Published in: The Astrophysical journal 2016-02, Vol.817 (2), p.167
• Main Authors: Kirk, H., Francesco, J. Di, Johnstone, D., Duarte-Cabral, A., Sadavoy, S., Hatchell, J., Mottram, J. C., Buckle, J., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Jenness, T., Nutter, D., Pattle, K., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Hogerheijde, M. R., Ward-Thompson, D., Bastien, P., Bresnahan, D., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Drabek-Maunder, E., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Mowat, C., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Rumble, D., Thomas, H., Tothill, N., Viti, S., White, G. J., Wouterloot, J., Yates, J., Zhu, M.
• Format: Article
• Language: English
• Subjects: ALGORITHMS; Aluminum base alloys; ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; Belts; CLOUDS; COSMIC DUST; DENSITY; dust, extinction; EXTRACTION; Fluxes; GALAXY CLUSTERS; GRAVITATIONAL COLLAPSE; MASS; PROTOSTARS; STAR CLUSTERS; Star formation; STARS; stars: formation; submillimeter: ISM
• ISSN: 0004-637X; 1538-4357
• DOI: 10.3847/0004-637X/817/2/167

ABSTRACT We present a first look at the SCUBA-2 observations of three sub-regions of the Orion B molecular cloud: LDN 1622, NGC 2023/2024, and NGC 2068/2071, from the JCMT Gould Belt Legacy Survey. We identify 29, 564, and 322 dense cores in L1622, NGC 2023/2024, and NGC 2068/2071 respectively, using the SCUBA-2 850 m map, and present their basic properties, including their peak fluxes, total fluxes, and sizes, and an estimate of the corresponding 450 m peak fluxes and total fluxes, using the FellWalker source extraction algorithm. Assuming a constant temperature of 20 K, the starless dense cores have a mass function similar to that found in previous dense core analyses, with a Salpeter-like slope at the high-mass end. The majority of cores appear stable to gravitational collapse when considering only thermal pressure; indeed, most of the cores which have masses above the thermal Jeans mass are already associated with at least one protostar. At higher cloud column densities, above 1-2 × 1023 cm−2, most of the mass is found within dense cores, while at lower cloud column densities, below 1 × 1023 cm−2, this fraction drops to 10% or lower. Overall, the fraction of dense cores associated with a protostar is quite small (