Table · dataset · 2024
Fractionation in young cores
Listed in IVOA Registry (Virtual Observatory)
Nitrogen fractionation is a powerful tracer of the chemical evolution during star- and planet formation.
Description
This requires robust determinations of the nitrogen fractionation across different evolutionary stages. We aim to determine the ^14^N/^15^N and ^12^C/^13^C ratios for HCN in six starless and prestellar cores and compare the results between the direct method using radiative transfer modeling and the indirect double isotope method assuming a fixed ^12^C/^13^C ratio.
We present IRAM observations of the HCN 1-0, HCN 3-2, HC^15^N 1-0 and H^13^CN 1-0 transitions toward six embedded cores. The ^14^N/^15^N ratio is derived using both the indirect double isotope method and directly through non-Local Thermodynamic Equilibrium 1D radiative transfer modeling of the HCN emission. The latter also provides the ^12^C/^13^C ratio, which is compared to the local interstellar value.
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The derived 14N/15N ratios using the indirect method are generally in the range 300-550 and could suggest an evolutionary trend in the nitrogen fractionation of HCN between starless cores and later stages of the star formation process. However, the direct method reveals lower fractionation ratios of around ~250, mainly resulting from a lower ^12^C/^13^C ratio in the range ~20-40 compared to the local interstellar medium value of 68.
This study reveals a significant difference between the nitrogen fractionation ratio in HCN derived using direct and indirect methods. This can influence the interpretation of the chemical evolution and displays the pitfalls of the indirect double isotope method for fractionation studies. However, the direct method is challenging as it requires well- constrained source models to produce accurate results.
No trend in the nitrogen fractionation of HCN between earlier and later stages of the star formation process is evident when the results of the direct method are considered.
Links
Where it is published
- Reference page cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/685/A149 ↗
landing page · from IVOA Registry
Documentation and papers
- ADS 2024A&A...685A.149J ui.adsabs.harvard.edu/abs/2024A%26A...685A.149J ↗
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/a%2Ba/685/a149 ↗
catalogue entry · from IVOA Registry
Topics
- Stated by source
- Millimeter
- From keywords
- Astronomy & Astrophysics
Provenance · 1 source records, 8 field assertions
| Source | Key | Last seen | Raw |
|---|---|---|---|
| IVOA Registry (Virtual Observatory) | ivo://cds.vizier/j/a+a/685/a149 | 15 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:millimeter | 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 |