Results of southern-hemisphere search for gamma-ray sources at Egamma ≥ 3×1011eV.
Abstract
Results are reported for a series of observations of possible high-energy gamma-ray sources in the Southern Hemisphere. The observations were made using the Narrabri optical intensity interferometer as a sensitive detector of Cerenkov light from extensive air showers initiated by high-energy gamma rays. The candidate sources included Cen A, the Vela pulsar, supernova 1972e, quasar 3C 273, the galactic center, and Cen X-3, as well as several other pulsars and X-ray sources. Upper flux limits for each object are presented together with equivocal evidence for a variable pulsed flux from the Vela pulsar. The results of the survey show that detectable sources exist at photon energies in excess of 100 GeV and that a number of sources of hard X-rays and 100-MeV gamma rays are not strong sources of high-energy gamma rays.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 1975
- DOI:
- 10.1086/153861
- Bibcode:
- 1975ApJ...201...82G
- Keywords:
-
- Gamma Rays;
- High Energy Interactions;
- X Ray Astronomy;
- Cerenkov Radiation;
- Galactic Nuclei;
- Interferometers;
- Pulsars;
- Quasars;
- Radiation Detectors;
- Southern Hemisphere;
- X Ray Sources;
- Astronomy