Table · dataset · 2024
Obs. of Gal. interstellar ratio ^18^O/^17^O. II.
Listed in IVOA Registry (Virtual Observatory)
Description
To investigate the relative amount of ejecta from high-mass versus intermediate-mass stars and to trace the chemical evolution of the Galaxy, we have performed a systematic study of Galactic interstellar ^18^O/^17^O ratios toward a sample of 421 molecular clouds with IRAM-30m and the 10m Submillimeter Telescope, covering a galactocentric distance range of ~1-22kpc. The results presented in this paper are based on the J=2-1 transition and encompass 364 sources showing both C^18^O and C^17^O detections.
The previously suggested ^18^O/^17^O gradient is confirmed. For the 41 sources detected with both facilities, good agreement is obtained. A correlation of the ^18^O/^17^O ratios with heliocentric distance is not found, indicating that beam dilution and linear beam sizes are not relevant.
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For the subsample of IRAM 30m high-mass star-forming regions with accurate parallax distances, an unweighted fit gives ^18^O/^17^O=(0.12+/-0.02)RGC+(2.38+/-0.13) with a correlation coefficient of R=0.67. While the slope is consistent with our J=1-0 measurement, the ratios are systematically lower. This should be caused by larger optical depths of C^18^O 2-1 lines with respect to the corresponding 1-0 transitions, which is supported by RADEX calculations and the fact that C18O/C17O is positively correlated with ^13^CO/C^18^O. When we consider that optical depth effects with C^18^O(J=2-1) typically reach an optical depth of ~0.5, the corrected ^18^O/^17^O ratios from the J=1-0 and J=2-1 lines are consistent.
A good numerical fit to the data is provided by the MWG-12 model, which includes both rotating stars and novae.
Links
Where it is published
- Reference page cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/268/56 ↗
landing page · from IVOA Registry
Documentation and papers
- ADS 2023ApJS..268...56Z ui.adsabs.harvard.edu/abs/2023ApJS..268...56Z ↗
publication · from IVOA Registry
Catalogue records · 2
- VOResource record dc.g-vo.org/oai.xml?verb=GetRecord&metadataPrefix=ivo_vor&identifier=ivo%3… ↗
metadata API · from IVOA Registry
- Registry record (GAVO) dc.g-vo.org/I/cds.vizier/j/apjs/268/56 ↗
catalogue entry · from IVOA Registry
Topics
- Stated by source
- Radio
- From keywords
- Astronomy & Astrophysics
Provenance · 1 source records, 8 field assertions
| Source | Key | Last seen | Raw |
|---|---|---|---|
| IVOA Registry (Virtual Observatory) | ivo://cds.vizier/j/apjs/268/56 | 12 d ago | JSON v1 |
| Field | Assertion | Extractor | Evidence |
|---|---|---|---|
| access_level | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| concepts[field].local:field:astronomy | mapping · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| concepts[modality].ivoa_waveband:radio | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| description | source · IVOA Registry | connector:ivoa_registry@1.0.0 | rr.resource.res_description |
| license_text | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| publication_date | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| title | source · IVOA Registry | connector:ivoa_registry@1.0.0 | rr.resource.res_title |
| updated_date | source · IVOA Registry | connector:ivoa_registry@1.0.0 |