SIMBAD references

2005A&A...430..549W - Astronomy and Astrophysics, volume 430, 549-560 (2005/2-1)

The interstellar C18O/C17O ratio in the solar neighbourhood: The ρ Ophiuchus cloud.


Abstract (from CDS):

Observations of up to ten carbon monoxide (CO and isotopomers) transitions are presented to study the interstellar C18O/C17O ratio towards 21 positions in the nearby (d∼140pc) low-mass star forming cloud ρ Oph. A map of the C18O J=1-0 distribution of parts of the cloud is also shown. An average 12C18O/12C17O isotopomeric ratio of 4.11±0.14, reflecting the 18O/17O isotope ratio, is derived from Large Velocity Gradient (LVG) calculations. From LTE column densities we derive a ratio of 4.17±0.26. These calculations also show that the kinetic temperature decreases from about 30K in the cloud envelope to about 10K in the cloud cores. This decrease is accompanied by an increase of the average molecular hydrogen density from 104cm–3 to >105cm–3. Towards some lines of sight C18O optical depths reach values of order unity.

Abstract Copyright:

Journal keyword(s): ISM: abundances - ISM: clouds - ISM: molecules - Galaxy: abundances - radio lines: ISM - ISM: individual objects: rho Oph

VizieR on-line data: <Available at CDS (J/A+A/430/549): table2.dat table3.dat spectra.dat sp/*>

Status at CDS:  

Simbad objects: 14

goto Full paper

goto View the reference in ADS

To bookmark this query, right click on this link: simbad:2005A&A...430..549W and select 'bookmark this link' or equivalent in the popup menu


© Université de Strasbourg/CNRS

    • Contact