The / abundance ratio in molecular clouds.
Abstract
Using the recently determined rest frequency of its first rotational transition, a sensitive search has been made for the J = 1 yields 0 transition of HOC(+) in 14 interstellar sources. A line having a frequency and shape consistent with optically thin emission due to this species was detected toward Sgr B2; this spectral feature is provisionally identified as being due to HOC(+). Comparison with the 1 yields 0 transition of H(C-18)O(+) in this source yields an isomeric abundance ratio HCO(+)/HOC(+) of about 330, if the detected line is in fact due to HOC(+). Independent of, and consistent with, this conclusion, comparisons with isotopically substituted HCO(+) in the other clouds searched show that HCO(+) is at least two orders of magnitude more abundant than HOC(+). This large ratio places interesting constraints on the fractional abundance of related species.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 1983
- DOI:
- 10.1086/161150
- Bibcode:
- 1983ApJ...270..583W
- Keywords:
-
- Abundance;
- Interstellar Matter;
- Molecular Clouds;
- Positive Ions;
- Brightness Temperature;
- Interstellar Chemistry;
- Molecular Ions;
- Astrophysics