Astronomy and Astrophysics – Astrophysics
Scientific paper
Jan 1996
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1996a%26a...305..558k&link_type=abstract
Astronomy and Astrophysics, v.305, p.558
Astronomy and Astrophysics
Astrophysics
14
Radio Lines: Ism, Ism: Abundances, Ism: Molecules, Ism: Clouds, Ism: Individual Objects: {Zeta} Oph
Scientific paper
Using the 15-m SEST submillimeter telescope, we have observed ^12^CO and ^13^CO in the diffuse molecular cloud lying close to ζ Oph, and searched for C^18^O, CS, CN and HCO^+^ at 2 particular positions. The ^12^CO(1-0) measurements show lines of the order of a few Kelvins in regions where the ^13^CO data seem to indicate diffuse material. We measure ^12^CO(1-0)/^13^CO(1-0) ratios of the order of 30 toward the positions of peak CO emission and lower limits of this ratio up to 65 in more diffuse regions. We compare these data with the predictions of a chemical model which solves consistently the thermal and chemical equilibrium of an interstellar cloud and computes the submillimeter and millimeter emergent line intensities of various atomic and molecular transitions. For the positions of peak CO emission, the model and observations agree satisfactorily for an isobaric cloud of pressure p=7.5x10^4^Kcm^-3^ or an isochoric cloud of density n(H_2_)=2500cm^-3^ permeated by an UV radiation field enhanced by a factor of 5 compared to the standard interstellar radiation field (ISRF) of Mathis et al. (???). The excitation properties of CO are consistent with a visual magnitude of the order of 1.2. The upper limit found for CS is also reproduced if the gas phase sulfur abundance is lower than the recent HST determinations.
Gerin Maryvonne
Kopp Marten
Le Bourlot Jacques
Roueff Evelyne
No associations
LandOfFree
Millimeter observations of ^12^CO and ^ 13^CO in the diffuse region around ζ Ophiuchi. 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 Millimeter observations of ^12^CO and ^ 13^CO in the diffuse region around ζ Ophiuchi., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Millimeter observations of ^12^CO and ^ 13^CO in the diffuse region around ζ Ophiuchi. will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-967001