EGRET Gamma-Ray Sources: GRO J0744+54 and GRO J0957+65 (= BL Lacertae Object 0954+658)
Abstract
EGRET detected an unidentified source, GRO J0744+54, at a significance of 6.5 σ, during its observations from 1993 June 28 to July 12. The source was seen again in the following 2 week viewing period and was weakly evident in the earlier phase 1 of the EGRET observations. Considering the variability of its gamma-ray flux, and its location at high Galactic latitude, GRO J0744+54 is likely to be a previously undetected blazar. Its most likely identification is with the radio source 87GB 073840.5+545138. A second source, GRO J0957+65, was seen by EGRET during the same two viewing periods at a combined significance of 5.7 σ. The most probable counterpart of GRO J0957+65 is the BL Lacertae object 0954+658. The spectra, time variability, and positions of the two sources are presented. Multiwavelength observations of 0954+658 are also presented.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 1995
- DOI:
- 10.1086/175685
- Bibcode:
- 1995ApJ...445..189M
- Keywords:
-
- Bl Lacertae Objects;
- Energy Spectra;
- Gamma Ray Spectra;
- Position (Location);
- Radio Spectra;
- Variability;
- Flux Density;
- Gamma Ray Astronomy;
- Gamma Ray Observatory;
- Spectral Energy Distribution;
- Spectrum Analysis;
- Astronomy;
- GAMMA RAYS: OBSERVATIONS;
- GALAXIES: BL LACERTAE OBJECTS: INDIVIDUAL ALPHANUMERIC: 0954+658