Shinnaga, Hiroko and Phillips, Thomas G. and Furuya, Ray S. and Kitamura, Yoshimi (2009) Warm extended dense gas at the heart of a cold collapsing dense core. Astrophysical Journal Letters, 706 (2). L226-L229. ISSN 0004-637X http://resolver.caltech.edu/CaltechAUTHORS:20100122-090116538
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In order to investigate when and how the birth of a protostellar core occurs, we made survey observations of four well-studied dense cores in the Taurus molecular cloud using CO transitions in submillimeter bands. We report here the detection of unexpectedly warm (~30-70 K), extended (radius of ~2400 AU), dense (a few times 10^5 cm^(–3)) gas at the heart of one of the dense cores, L1521F (MC27), within the cold dynamically collapsing components. We argue that the detected warm, extended, dense gas may originate from shock regions caused by collisions between the dynamically collapsing components and outflowing/rotating components within the dense core. We propose a new stage of star formation, "warm-in-cold core stage (WICCS)," i.e., the cold collapsing envelope encases the warm extended dense gas at the center due to the formation of a protostellar core. WICCS would constitute a missing link in evolution between a cold quiescent starless core and a young protostar in class 0 stage that has a large-scale bipolar outflow.
|Additional Information:||© 2009. The American Astronomical Society. All rights reserved. Received 2009 August 18; accepted 2009 October 2; published 2009 November 12. This research was performed at the Caltech Submillimeter Observatory, supported by NSF grants AST-05-40882 and AST- 0838261. This work was also supported by Grant-in-Aids from the Ministry of Education, Culture, Sports, Science and Technology of Japan (No. 19204020 and No. 20740113). H.S. is grateful to Richard Chamberlin, Brian Force, and Hiroshige Yoshida for their support on the observations in 2009 January.|
|Subject Keywords:||ISM: clouds; ISM: individual (L1521F, MC27); stars: formation; stars: pre-main sequence; submillimeter|
|Official Citation:||Warm Extended Dense Gas at the Heart of a Cold Collapsing Dense Core Hiroko Shinnaga, Thomas G. Phillips, Ray S. Furuya, and Yoshimi Kitamura 2009 ApJ 706 L226-L229 doi: 10.1088/0004-637X/706/2/L226|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Ruth Sustaita|
|Deposited On:||25 Jan 2010 19:10|
|Last Modified:||26 Dec 2012 11:43|
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