Carbon monoxide in the Magellanic Clouds

Abstract

view Abstract Citations (109) References (52) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Carbon Monoxide in the Magellanic Clouds Israel, F. P. ; de Graauw, Th. ; van de Stadt, H. ; de Vries, C. P. Abstract C-12O (2-1) emission has been detected at 11 of 22 positions in the LMC and, for the first time, at 6 of 16 positions in the SMC. All but one of the presently known Magellanic Cloud masers are associated with CO clouds; CO emission was also detected in the direction of several dark clouds and bright H II regions. In the LMC, the region south of 30 Doradus appears to be richest in CO, while in the SMC most detections are in the southwestern part of the Bar. CO emission from Magellanic Cloud objects tends to be weaker than that from Galactic objects; in addition, it is less widespread in the SMC than in either the Galaxy or the LMC. It is suggested that the combination of relatively low C and O abundances, relatively low gas-to-dust ratios, and relatively strong mean UV radiation fields in the Magellanic Clouds is the principal cause of these differences. In turn, this implies that use of the Galactic CO to H2 ratio significantly underestimates the H2 content of the Clouds. Such a result is consistent with models of stochastic star formation; consequently, low CO intensities may be a general property of low-mass galaxies in an active star-bursting phase, as is suggested by observations. Publication: The Astrophysical Journal Pub Date: April 1986 DOI: 10.1086/164065 Bibcode: 1986ApJ...303..186I Keywords: Astronomical Spectroscopy; Carbon Monoxide; Magellanic Clouds; Molecular Clouds; Stellar Evolution; Emission Spectra; H Ii Regions; Masers; Milky Way Galaxy; Stochastic Processes; Astrophysics; GALAXIES: MAGELLANIC CLOUDS; INTERSTELLAR: MOLECULES; MASERS; STARS: FORMATION full text sources ADS | data products SIMBAD (2) NED (1)