The JCMT Gould Belt Survey: first results from the SCUBA-2 observations of the Ophiuchus molecular cloud and a virial analysis of its prestellar core population
Date Issued
2015
Author(s)
Pattle, K.
•
Ward-Thompson, D.
•
Kirk, J. M.
•
White, G. J.
•
Drabek-Maunder, E.
•
Buckle, J.
•
Beaulieu, S. F.
•
Berry, D. S.
•
Broekhoven-Fiene, H.
•
Currie, M. J.
•
Fich, M.
•
Hatchell, J.
•
Kirk, H.
•
Jenness, T.
•
Johnstone, D.
•
Mottram, J. C.
•
Nutter, D.
•
Pineda, J. E.
•
Quinn, C.
•
Salji, C.
•
Tisi, S.
•
Walker-Smith, S.
•
di Francesco, J.
•
Hogerheijde, M. R.
•
André, Ph.
•
Bastien, P.
•
Bresnahan, D.
•
Butner, H.
•
Chen, M.
•
Chrysostomou, A.
•
Coude, S.
•
Davis, C. J.
•
Duarte-Cabral, A.
•
Fiege, J.
•
Friberg, P.
•
Friesen, R.
•
Fuller, G. A.
•
Graves, S.
•
Greaves, J.
•
Gregson, J.
•
Griffin, M. J.
•
Holland, W.
•
Joncas, G.
•
Knee, L. B. G.
•
Könyves, V.
•
Mairs, S.
•
Marsh, K.
•
Matthews, B. C.
•
Moriarty-Schieven, G.
•
Rawlings, J.
•
Richer, J.
•
Robertson, D.
•
Rosolowsky, E.
•
Rumble, D.
•
Sadavoy, S.
•
•
Thomas, H.
•
Tothill, N.
•
Viti, S.
•
Wouterloot, J.
•
Yates, J.
•
Zhu, M.
Description
KP wishes to thank STFC for studentship support while this research was carried out. The JCMT has historically been operated by the Joint Astronomy Centre on behalf of the Science and Technology Facilities Council of the United Kingdom, the National Research Council of Canada, and the Netherlands Organisation for Scientific Research. Additional funds for the construction of SCUBA-2 were provided by the Canada Foundation for Innovation. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain).
Abstract
In this paper, we present the first observations of the Ophiuchus molecular cloud performed as part of the James Clerk Maxwell Telescope (JCMT) Gould Belt Survey (GBS) with the SCUBA-2 instrument. We demonstrate methods for combining these data with previous HARP CO, Herschel, and IRAM N2H+ observations in order to accurately quantify the properties of the SCUBA-2 sources in Ophiuchus. We produce a catalogue of all of the sources found by SCUBA-2. We separate these into protostars and starless cores. We list all of the starless cores and perform a full virial analysis, including external pressure. This is the first time that external pressure has been included in this level of detail. We find that the majority of our cores are either bound or virialized. Gravitational energy and external pressure are on average of a similar order of magnitude, but with some variation from region to region. We find that cores in the Oph A region are gravitationally bound prestellar cores, while cores in the Oph C and E regions are pressure-confined. We determine that N2H+ is a good tracer of the bound material of prestellar cores, although we find some evidence for N2H+ freeze-out at the very highest core densities. We find that non-thermal linewidths decrease substantially between the gas traced by C18O and that traced by N2H+, indicating the dissipation of turbulence at higher densities. We find that the critical Bonnor-Ebert stability criterion is not a good indicator of the boundedness of our cores. We detect the pre-brown dwarf candidate Oph B-11 and find a flux density and mass consistent with previous work. We discuss regional variations in the nature of the cores and find further support for our previous hypothesis of a global evolutionary gradient across the cloud from south-west to north-east, indicating sequential star formation across the region.
Volume
450
Issue
1
Start page
1094
Issn Identifier
0035-8711
Ads BibCode
2015MNRAS.450.1094P
Rights
open.access
File(s)![Thumbnail Image]()
Loading...
Name
stv376 compr.pdf
Description
Pdf editoriale
Size
1.31 MB
Format
Adobe PDF
Checksum (MD5)
620f9103b012396ed65b85afdf12140f