8200 to 11200 Å spectra of peculiar emission-line objects with infrared excess.
Abstract
Spectra of 25 peculiar emission-line stars with IR excesses are presented which were obtained in the near-IR region from 8200 to 11,200 A with a grating spectrograph and an S-1 photocathode image tube at the Cassegrain focus of a 1.93-m telescope. The observations were conducted to detect the Paschen series as well as emission lines due to permitted and forbidden transitions. The strongest emission features are found to be the Paschen series from P6 to P21, the Ca II triplet at 8498-8542-8662 A, the He I line at 10830 A, the O I line at 8446 A, the forbidden S III lines at 9069 and 9532 A, and the forbidden Fe III line at 10504 A. A strong emission line at 9999 A was observed in almost all the spectra, but remains unidentified. It is noted that the richness in emission lines becomes remarkable for the objects whose H - K index is of the order of or greater than unity, indicating that an H - K value of approximately 1.0 may serve to distinguish objects with rich emission spectra.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 1976
- DOI:
- 10.1086/182069
- Bibcode:
- 1976ApJ...204L.123A
- Keywords:
-
- Emission Spectra;
- Infrared Spectra;
- Near Infrared Radiation;
- Paschen Series;
- Stellar Spectra;
- Astronomical Spectroscopy;
- Forbidden Transitions;
- Helium Atoms;
- Line Spectra;
- Oxygen Atoms;
- Astrophysics