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Dense gas in IRAS 20343+4129: an ultracompact H II region caught in the act of creating a cavity

Fontani, F. and Palau, Aina and Busquet, G. and Isella, A. and Estalella, R. and Sanchez-Monge, Á. and Caselli, P. and Zhang, Q. (2012) Dense gas in IRAS 20343+4129: an ultracompact H II region caught in the act of creating a cavity. Monthly Notices of the Royal Astronomical Society, 423 (2). pp. 1691-1706. ISSN 0035-8711. doi:10.1111/j.1365-2966.2012.20990.x.

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The intermediate- to high-mass star-forming region IRAS 20343+4129 is an excellent laboratory to study the influence of high- and intermediate-mass young stellar objects on nearby starless dense cores, and investigate for possible implications in the clustered star formation process. We present 3 mm observations of continuum and rotational transitions of several molecular species (C_(2)H, c-C_(3)H_(2), N_(2)H+, NH_(2)D) obtained with the Combined Array for Research in Millimetre-wave Astronomy, as well as 1.3 cm continuum and NH_3 observations carried out with the Very Large Array, to reveal the properties of the dense gas. We confirm undoubtedly previous claims of an expanding cavity created by an ultracompact H ii region associated with a young B2 zero-age main sequence (ZAMS) star. The dense gas surrounding the cavity is distributed in a filament that seems squeezed in between the cavity and a collimated outflow associated with an intermediate-mass protostar. We have identified 5 mm continuum condensations in the filament. All of them show column densities consistent with potentially being the birthplace of intermediate- to high-mass objects. These cores appear different from those observed in low-mass clustered environments in several observational aspects (kinematics, temperature, chemical gradients), indicating a strong influence of the most massive and evolved members of the protocluster. We suggest a possible scenario in which the B2 ZAMS star driving the cavity has compressed the surrounding gas, perturbed its properties and induced the star formation in its immediate surroundings.

Item Type:Article
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URLURL TypeDescription
Fontani, F.0000-0003-0348-3418
Isella, A.0000-0001-8061-2207
Caselli, P.0000-0003-1481-7911
Additional Information:© 2012 The Authors. Monthly Notices of the Royal Astronomical Society © 2012 RAS. Accepted 2012 March 23; Received 2012 March 23; in original form 2012 January 4. Article first published online: 26 Apr. 2012. Support for CARMA construction was derived from the Gordon and Betty Moore Foundation, the Kenneth T. and Eileen L. Norris Foundation, the James S. McDonnell Foundation, the Associates of the California Institute of Technology, the University of Chicago, the states of California, Illinois, and Maryland, and the National Science Foundation. Ongoing CARMA development and operations are supported by the National Science Foundation under a cooperative agreement, and by the CARMA partner universities. We acknowledge support from the Owens Valley Radio Observatory, which is supported by the National Science Foundation through grant AST 05-40399. AP is grateful to Inma Sepúlveda for insightful discussions. AP is supported by the Spanish MICINN grant AYA2008-06189-C03 (co-funded with FEDER funds) and by a JAE-Doc CSIC fellowship co-funded with the European Social Fund under the programme ‘Junta para la Ampliación de Estudios’. GB is funded by an Italian Space Agency (ASI) fellowship under contract number I/005/07/01. We are grateful to the anonymous referee for his/her valuable comments and suggestions.
Funding AgencyGrant Number
Owens Valley Radio ObservatoryUNSPECIFIED
Spanish MICINN grantAYA2008-06189-C03
Italian Space Agency (ASI)I/005/07/01
NSFAST 05-40399
European Social FundUNSPECIFIED
Subject Keywords:stars: formation; ISM: individual objects: IRAS 20343+4129; ISM: molecules
Issue or Number:2
Record Number:CaltechAUTHORS:20120710-133651084
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Official Citation:Fontani, F., Palau, A., Busquet, G., Isella, A., Estalella, R., Sanchez-Monge, Á., Caselli, P. and Zhang, Q. (2012), Dense gas in IRAS 20343+4129: an ultracompact H ii region caught in the act of creating a cavity. Monthly Notices of the Royal Astronomical Society, 423: 1691–1706. doi: 10.1111/j.1365-2966.2012.20990.x
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:32335
Deposited By: Jason Perez
Deposited On:10 Jul 2012 21:14
Last Modified:09 Nov 2021 21:26

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