Astronomy and Astrophysics – Astrophysics
Scientific paper
2005-04-07
Astronomy and Astrophysics
Astrophysics
10 pages, 6 figures, accepted for publication in A&A
Scientific paper
10.1051/0004-6361:20052737
As an independent check on previous measurements of the isotopic abundance of oxygen through the Galaxy, we present a detailed analysis of the ground state rotational lines of 16OH and 18OH in absorption towards the giant molecular cloud complex, Sagittarius B2. We have modelled the line shapes to separate the contribution of several galactic clouds along the line of sight and calculate 16OH/18OH ratios for each of these features. The best fitting values are in the range 320-540, consistent with the previous measurements in the Galactic Disk but slightly higher than the standard ratio in the Galactic Centre. They do not show clear evidence for a gradient in the isotopic ratio with galactocentric distance. The individual 16OH column densities relative to water give ratios of [H2O/OH]=0.6-1.2, similar in magnitude to galactic clouds in the sight lines towards W51 and W49. A comparison with CH indicates [OH/CH] ratios higher than has been previously observed in diffuse clouds. We estimate OH abundances of 10^-7 - 10^-6 in the line of sight features.
Baluteau Jean-Paul
Polehampton Edward T.
Swinyard Bruce M.
No associations
LandOfFree
Oxygen isotopic ratios in galactic clouds along the line of sight towards Sagittarius B2 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 Oxygen isotopic ratios in galactic clouds along the line of sight towards Sagittarius B2, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Oxygen isotopic ratios in galactic clouds along the line of sight towards Sagittarius B2 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-363265