The probable detection of interstellar 3He+ and its significance.
Abstract
A search has been conducted for the hyperfine line of He-3(+) at 8.7 GHz in several H II regions and in planetary nebulae located more than 500 pc from the galactic plane. A probable detection of He-3(+) in W51 is reported, along with an He-3(+)/H(+) abundance ratio of about 0.00004 by number for this source and upper limits to the He-3(+) abundance in five other sources. The ratio of He-3(+) to H(+) in W51 is found to be equal to the ratio of He-3 to H, and the relative abundance in W51 is estimated to be roughly comparable to the protosolar value. It is tentatively concluded that the contribution of He-3 to the interstellar medium by low-mass stars is much smaller than that estimated by Rood et al. (1976).
- Publication:
-
The Astrophysical Journal
- Pub Date:
- January 1979
- DOI:
- 10.1086/182875
- Bibcode:
- 1979ApJ...227L..97R
- Keywords:
-
- Abundance;
- Helium;
- Interstellar Gas;
- Planetary Nebulae;
- H Ii Regions;
- Hyperfine Structure;
- Astrophysics;
- H II Regions:Helium;
- Helium:Interstellar Matter;
- Helium:Planetary Nebulae