Observations of DCO+: the electron abundance in dark clouds.
Abstract
The J equals 2-1 rotational line of DCO(plus) has been definitely detected in five molecular clouds, including three dark clouds, L63, L134, and L134 N, and marginally detected in four others. The DCO(plus) emission has been mapped in L134 N and extends over a region of 3 arcmin. The DCO(plus)/HCO(plus) abundance ratio found at the centers of dark clouds is large and implies a fractional electron abundance of less than one hundred millionth. This low electron density sets constraints on the metals and possibly CO as well as on the hydrogen density.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 1977
- DOI:
- 10.1086/182562
- Bibcode:
- 1977ApJ...217L.165G
- Keywords:
-
- Deuterium Compounds;
- Electron Density (Concentration);
- Molecular Ions;
- Molecular Spectra;
- Nebulae;
- Abundance;
- Carbon Monoxide;
- Clouds;
- Free Radicals;
- Interstellar Matter;
- Molecular Rotation;
- Astrophysics