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

Journal Article · Mon Feb 01 00:00:00 EST 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/817/2/167· OSTI ID:22521612

Kirk, H.; Francesco, J. Di; Johnstone, D. ^[1]; Duarte-Cabral, A.; Hatchell, J. ^[2]; Sadavoy, S.; Mottram, J. C. ^[3]; Buckle, J.; Salji, C. ^[4]; Berry, D. S.; Currie, M. J.; Jenness, T. ^[5]; Broekhoven-Fiene, H. ^[6]; Fich, M.; Tisi, S. ^[7]; Nutter, D.; Quinn, C. ^[8]; Pattle, K. ^[9]; Pineda, J. E. ^[10]; Hogerheijde, M. R. ^[11] ; others, and

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1. NRC Herzberg Astronomy and Astrophysics, 5071 West Saanich Rd, Victoria, BC, V9E 2E7 (Canada)
2. Physics and Astronomy, University of Exeter, Stocker Road, Exeter EX4 4QL (United Kingdom)
3. Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany)
4. Astrophysics Group, Cavendish Laboratory, J J Thomson Avenue, Cambridge, CB3 0HE (United Kingdom)
5. Joint Astronomy Centre, 660 N. A‘ohōkū Place, University Park, Hilo, Hawaii 96720 (United States)
6. Department of Physics and Astronomy, University of Victoria, Victoria, BC, V8P 1A1 (Canada)
7. Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada)
8. School of Physics and Astronomy, Cardiff University, The Parade, Cardiff, CF24 3AA (United Kingdom)
9. Jeremiah Horrocks Institute, University of Central Lancashire, Preston, Lancashire, PR1 2HE (United Kingdom)
10. European Southern Observatory (ESO), Garching (Germany)
11. Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands)

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 μm map, and present their basic properties, including their peak fluxes, total fluxes, and sizes, and an estimate of the corresponding 450 μm 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 × 10{sup 23} cm{sup −2}, most of the mass is found within dense cores, while at lower cloud column densities, below 1 × 10{sup 23} cm{sup −2}, this fraction drops to 10% or lower. Overall, the fraction of dense cores associated with a protostar is quite small (<8%), but becomes larger for the densest and most centrally concentrated cores. NGC 2023/2024 and NGC 2068/2071 appear to be on the path to forming a significant number of stars in the future, while L1622 has little additional mass in dense cores to form many new stars.

• OSTI ID: 22521612
• Journal Information: Astrophysical Journal, Vol. 817, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ALGORITHMS
CLOUDS
COSMIC DUST
DENSITY
EXTRACTION
GALAXY CLUSTERS
GRAVITATIONAL COLLAPSE
MASS
PROTOSTARS
STAR CLUSTERS
STARS