Astronomy and Astrophysics – Astrophysics
Scientific paper
2008-09-10
Astrophys.J.690:580-597,2009
Astronomy and Astrophysics
Astrophysics
50 pages, 13 figures, accepted for publication in ApJ
Scientific paper
10.1088/0004-637X/690/1/580
With the goal of deriving the physical and chemical conditions of star forming regions in the Large Magellanic Cloud (LMC), a spectral line survey of the prominent star forming region N113 is presented. The observations cover parts of the frequency range from 85 GHz to 357 GHz and include 63 molecular transitions from a total of 16 species, among them spectra of rare isotopologues. Maps of selected molecular lines as well as the 1.2 mm continuum distribution are also presented. Molecular abundances in the core of the complex are found to be consistent with a photon dominated region (PDR) that is nitrogen deficient, with the potential exception of N2H+. Densities range from 5x10^3 cm-3 for CO to almost 10^6 for CS and HCN, indicating that only the densest regions provide sufficient shielding even for some of the most common species. An ortho- to para-H_2CO ratio of ~3 hints at H_2CO formation in a warm (>=40 K) environment. Isotope ratios are 12C/13C ~ 49+-5, 16O/18O ~ 2000+-250, 18O/17O ~ 1.7+-0.2 and 32S/34S ~ 15. Agreement with data from other star forming clouds shows that the gas is well mixed in the LMC . The isotope ratios do not only differ from those seen in the Galaxy. They also do not form a continuation of the trends observed with decreasing metallicity from the inner to the outer Galaxy. This implies that the outer Galaxy, is not providing a transition zone between the inner Galaxy and the metal poor environment of the Magellanic Clouds. A part of this discrepancy is likely caused by differences in the age of the stellar populations in the outer Galaxy and the LMC.
Chin Y.-N.
Cunningham Maria
Henkel Carsten
Wang Min
Whiteoak John B.
No associations
LandOfFree
Abundances and Isotope Ratios in the Magellanic Clouds: The Star Forming Environment of N113 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Abundances and Isotope Ratios in the Magellanic Clouds: The Star Forming Environment of N113, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Abundances and Isotope Ratios in the Magellanic Clouds: The Star Forming Environment of N113 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-160882