Optical pulsations in HZ Herculis. III. Discovery of pulsed emission lines.
Abstract
Observations are reported of periodic optical pulses from HZ Her in a 100-A band containing the He II 4686-A emission line and the N III 4640-A multiplet. It is shown that one-third of the total pulsed component of the optical emission is associated with these emission lines and that one or more of these lines is probably strongly pulsed, implying an extremely high efficiency of X-ray-to-optical pulse reprocessing. The velocity and acceleration of the emitting region are derived and indicate that one or both lines originate at HZ Her. It is proposed that the pulsed lines are formed in a dense region in the atmosphere of HZ Her and that radiative recombinations of He II and dielectronic recombinations of N III can explain the observed pulsed emission-line strengths.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 1975
- DOI:
- 10.1086/153643
- Bibcode:
- 1975ApJ...198..653D
- Keywords:
-
- Emission Spectra;
- Light Emission;
- Pulsed Radiation;
- Stellar Radiation;
- X Ray Stars;
- Binary Stars;
- Line Spectra;
- O Stars;
- Recombination Reactions;
- Stellar Spectra;
- Astrophysics