Molecular and Atomic Gas in the Large Magellanic Cloud. Ii. Three-dimensional Correlation Between Co and H I
Year: 2009
Type: article
Abstract: 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] ∝ [average H i intensity] 1.1±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 −1 and the mean density in the envelope is 10 cm −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 ☉ yr −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.
Source: The Astrophysical Journal
Institutions: Nagoya University, University of Illinois Urbana-Champaign, National Astronomical Observatory of Japan, Osaka Prefecture University, Commonwealth Scientific and Industrial Research Organisation, Australia Telescope National Facility, Swinburne University of Technology, California Institute of Technology, National Radio Astronomy Observatory, The University of Western Australia, Sejong University
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2131117833