Detection of the linear SiC<sub>3</sub> and SiC<sub>5</sub> radicals in IRC+10216
We detected the linear 3 Σ − radicals SiC 3 and SiC 5 toward IRC+10216 using an ultrasensitive line survey gathered with the Yebes 40 m radio telescope. The derived column densities of l -SiC 3 and l -SiC 5 are (3.6 ± 0.4) × 10 12 cm −2 and (1.8 ± 0.2) × 10 12 cm −2 , respectively. The linear SiC 3 radical is ∼2 times less abundant that its singlet rhomboidal prolate isomer, for which we provide a new analysis based on recent sensitive observations in the Q band (7 mm), and at 3 and 2 mm with the IRAM 30 m telescope. The emission detected from these species arises from the cool external layers of the circumstellar envelope. We speculate whether ion-neutral routes involving SiC n H m + cations or neutral-neutral reactions involving Si and SiC 2 could efficiently synthesize these species.
Authors
- L. Velilla-Prieto (ORCID: https://orcid.org/0000-0001-8275-9341)
- P. de Vicente (ORCID: https://orcid.org/0000-0002-5902-5005)
- M. Guélin (ORCID: https://orcid.org/0000-0002-4896-500X)
- J. R. Pardo (ORCID: https://orcid.org/0000-0003-4639-8440)
- M. Agúndez (ORCID: https://orcid.org/0000-0003-3248-3564)
- J. P. Fonfría (ORCID: https://orcid.org/0000-0002-6556-6692)
- J. Cernicharo (ORCID: https://orcid.org/0000-0002-3518-2524)
- C. Cabezas (ORCID: https://orcid.org/0000-0002-1254-7738)
- B. Tercero (ORCID: https://orcid.org/0000-0002-4782-5259)
Institutions
- Instituto de Física Fundamental (ES)
- Institut de Radioastronomie Millimétrique (FR)
- Yebes Observatory (ES)
- Spanish National Observatory (ES)
Publication Details
- Journal
- Astronomy and Astrophysics
- Published
- 2025-08-01
- DOI
- https://doi.org/10.1051/0004-6361/202556370
- Citations
- 2
- Primary Topic
- Astrophysics and Star Formation Studies
- Type
- article
- Field-Weighted Citation Impact
- 2.31
Funders
- European Research Council
- Agencia Estatal de Investigación
- European Social Fund