The star-forming core of Monoceros R2

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dc.creator Giannakopoulou, Jean
dc.creator Mitchell, George F.
dc.creator Hasegawa, Tatsuhiko I.
dc.creator Matthews, Henry E.
dc.creator Maillard, Jean-Pierre
dc.date.accessioned 2015-02-11T16:43:09Z
dc.date.available 2015-02-11T16:43:09Z
dc.date.issued 1997-09
dc.identifier.issn 0004-637X
dc.identifier.issn 1538-4357
dc.identifier.uri http://library2.smu.ca/xmlui/handle/01/25955
dc.description Publisher's version/PDF en_CA
dc.description.abstract The central region of the Monoceros R2 molecular cloud has been studied using molecular line maps, maps in continuum emission, and an M-band (4.7 [micrometres]) absorption spectrum toward Mon R2 IRS 3. Maps were made in the emission lines CO (3-2) H[subscript 2]CO (5[subscript 1.5]-4[subscript 1.4), and HCN (4-3), all with a 14" beam size. CO (2-1) and [superscript 13]CO (3-2) spectra were obtained at a dozen positions. Maps of continuum emission were made at 1300 [micrometres] (25" resolution), 1100 [micrometres] (20" resolution), 800 [micrometres] (14" resolution), and 450 [micrometres] (14" resolution). The M-band spectrum of IRS 3 has a velocity resolution of 5.2 km s[superscript -1] and shows fundamental vibrational band absorption lines of CO and [superscript 13]CO over a range of rotational states. The CO map has numerous intensity peaks which, if interpreted as clumps, have masses from 0.1 to 3 M [subscript circled dot]. The large velocity dispersion of these structures implies that they cannot be gravitationally bound. The brightest CO-emitting gas shows no bipolar distribution with velocity. Diffuse CO-emitting gas with low velocities does have a generally bipolar distribution, but there are no collimated lobes pointing to a particular source. We conclude that the source (or sources) of the very extended Mon R2 outflow is (are) now inactive. The highest velocity gas is found toward the embedded young stellar object IRS 3, suggesting that IRS 3 is the source of a compact outflow, unresolved at our 14" resolution. The presence of blueshifted CO in the absorption spectrum supports the interpretation of IRS 3 as an outflow source. The H[subscript 2]CO and HCN maps demonstrate that much of the dense gas is distributed within three structures having different velocities. The fundamental band absorption lines of [superscript 13]CO show two gas temperatures in the line of sight to IRS 3. The colder (45 K) is identified as gas in the clump surrounding IRS 3, which is seen in emission lines of CO, H[subscript 2]CO, and HCN. The warmer (310 K) we interpret as gas very close to IRS 3. From the submillimeter continuum maps we identify 11 clumps whose masses lie in the range 3-10 M [subscript circled dot]. A clump that is prominent in the continuum maps but not in the molecular line maps is attributed to heated dust inside the compact H II region, where molecules have been destroyed. en_CA
dc.language.iso en en_CA
dc.publisher American Astronomical Society en_CA
dc.relation.uri http://dx.doi.org/10.1086/304574
dc.rights Article is made available in accordance with the publisher’s policy and is subject to copyright law. Please refer to the publisher’s site. Any re-use of this article is to be in accordance with the publisher’s copyright policy. This posting is in no way granting any permission for re-use to the reader/user.
dc.subject.lcsh Molecular clouds
dc.subject.lcsh Interstellar matter
dc.subject.lcsh Stars -- Formation
dc.title The star-forming core of Monoceros R2 en_CA
dc.type Text en_CA
dcterms.bibliographicCitation Astrophysical Journal 487(1), 346-364. (1997) en_CA


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Article is made available in accordance with the publisher’s policy and is subject to copyright law. Please refer to the publisher’s site. Any re-use of this article is to be in accordance with the publisher’s copyright policy. This posting is in no way granting any permission for re-use to the reader/user.
 
Published Version: http://dx.doi.org/10.1086/304574
 
 

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