Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/209931

Title

The Magellanic Mopra Assessment (MAGMA) I: the molecular cloud population of the Large Magellanic Cloud

Author(s)

Wong, Tony;  Hughes, Annie;  Ott, Juergen;  Muller, Erik;  Pineda, Jorge L.;  Bernard, Jean-Philippe;  Chu, You-Hua;  Fukui, Yasuo;  Gruendl, Robert A.;  Henkel, Christian;  Kawamura, Akiko;  Klein, Ulrich;  Looney, Leslie W.;  Maddison, Sarah;  Mizuno, Yoji;  Paradis, Deborah;  Seale, Jonathan;  Welty, Daniel E.

Abstract

We present the properties of an extensive sample of molecular clouds in the Large Magellanic Cloud (LMC) mapped at 11 pc resolution in the CO(1-0) line. We identify clouds as regions of connected CO emission, and find that the distributions of cloud sizes, fluxes and masses are sensitive to the choice of decomposition parameters. In all cases, however, the luminosity function of CO clouds is steeper than dN/dL \propto L^{-2}, suggesting that a substantial fraction of mass is in low-mass clouds. A correlation between size and linewidth, while apparent for the largest emission structures, breaks down when those structures are decomposed into smaller structures. We argue that the correlation between virial mass and CO luminosity is the result of comparing two covariant quantities, with the correlation appearing tighter on larger scales where a size-linewidth relation holds. The virial parameter (the ratio of a cloud's kinetic to self-gravitational energy) shows a wide range of values and exhibits no clear trends with the CO luminosity or the likelihood of hosting young stellar object (YSO) candidates, casting further doubt on the assumption of virialization for molecular clouds in the LMC. Higher CO luminosity increases the likelihood of a cloud harboring a YSO candidate, and more luminous YSOs are more likely to be coincident with detectable CO emission, confirming the close link between giant molecular clouds and massive star formation.

Publication type

Journal article

Research centre

Swinburne University of Technology. Faculty of Information and Communication Technologies. Centre for Astrophysics and Supercomputing

Source

The Astrophysical Journal Supplement Series, Vol. 197, no. 2 (Dec 2011)

Publication year

2011

FOR Code(s)

0201 Astronomical and Space Sciences;  0305 Organic Chemistry;  0306 Physical Chemistry (Incl. Structural)

Keyword(s)

ISM galaxies;  Large Magellanic Cloud;  Magellanic clouds;  Molecules;  Star formation

Publisher

Institute of Physics Publishing

ISSN

0067-0049

Publisher URL

http://dx.doi.org/10.1088/0067-0049/197/2/16

Copyright

Copyright © 2011 The American Astronomical Society. All rights reserved. The American Astronomical Society does not allow institutions to archive either the accepted manuscript or the published version of the article. However, you can find an earlier version of the full text here: http://arxiv.org/abs/1108.5715

Additional information

The full resolution version of the publication and data tables are available here: http://mmwave.astro.illinois.edu/magma/

Peer reviewed