MOLECULAR AND ATOMIC GAS IN THE LARGE MAGELLANIC CLOUD. II. THREE-DIMENSIONAL CORRELATION BETWEEN CO AND H I

Journal Article · Sun Nov 01 00:00:00 EDT 2009 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/705/1/144· OSTI ID:21378408

Fukui, Y; Kawamura, A; Murai, M; Iritani, H; Mizuno, N; Mizuno, Y; Onishi, T; Muller, E ^[1]; Wong, T ^[2]; Hughes, A ^[3]; Ott, J ^[4]; Staveley-Smith, L ^[5]; Kim, S ^[6]

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1. Department of Astrophysics, Nagoya University, Furocho, Chikusaku, Nagoya 464-8602 (Japan)
2. Astronomy Department, University of Illinois, 1002 W. Green Street, Urbana, IL 61801 (United States)
3. Centre for Astrophysics and Supercomputing, Swinburne University of Technology, P.O. Box 218, Hawthorn, VIC 3122 (Australia)
4. National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States)
5. School of Physics M013, University of Western Australia, Crawley, WA 6009 (Australia)
6. Department of Astronomy and Space Science, Sejong University, KwangJin-gu, KunJa-dong 98, Seoul 143-747 (Korea, Republic of)

We compare the CO (J = 1-0) and H I emission in the Large Magellanic Cloud in three dimensions, i.e., including a velocity axis in addition to the two spatial axes, with the aim of elucidating the physical connection between giant molecular clouds (GMCs) and their surrounding H I gas. The CO J = 1-0 data set is from the second NANTEN CO survey and the H I data set is from the merged Australia Telescope Compact Array (ATCA) and Parkes Telescope surveys. The major findings of our analysis are as follows: (1) GMCs are associated with an envelope of H I emission, (2) in GMCs [average CO intensity] propor to [average H I intensity]{sup 1.1+}-{sup 0.1}, and (3) the H I intensity tends to increase with the star formation activity within GMCs, from Type I to Type III. An analysis of the H I envelopes associated with GMCs shows that their average line width is 14 km s{sup -1} and the mean density in the envelope is 10 cm{sup -3}. We argue that the H I envelopes are gravitationally bound by GMCs. These findings are consistent with a continual increase in the mass of GMCs via H I accretion at an accretion rate of 0.05 M{sub sun} yr{sup -1} over a timescale of 10 Myr. The growth of GMCs is terminated via dissipative ionization and/or stellar-wind disruption in the final stage of GMC evolution.

• OSTI ID: 21378408
• Journal Information: Astrophysical Journal, Vol. 705, Issue 1; Other Information: DOI: 10.1088/0004-637X/705/1/144; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
EMISSION
IONIZATION
LINE WIDTHS
MAGELLANIC CLOUDS
STARS
STELLAR WINDS
TELESCOPES
THREE-DIMENSIONAL CALCULATIONS
GALAXIES
STELLAR ACTIVITY