Detection of a Flaring Low-Energy Gamma-Ray Source
Abstract
We report the detection of a flaring gamma-ray source by the University of New Hampshire (UNH) balloon-borne coded aperture gamma-ray telescope (DGT) on 1984 October 2. The source was detected at the significance level of 7.2 sigma over the energy range 160-2000 keV. The intensity in the range (160-200) keV was 1.1 Crab. The best-fit position of the source is given by R.A. = 3h 25.8m and Decl. = 67 deg 653 min and is located in the constellation of Camelopardia. The source was visible within the Field of View (FOV) of the telescope for approximately = 2 hr and exhibited signs of flaring. The derived photon spectrum can be equally fitted by an optically thin bremsstrahlung distribution of kT approximately = 52 keV or a power law of the form, dN(E)/dE = 3.7 x 10-6 (E/400)-4.5 photons/sq cm/keV. We compare its spectral characteristics ad energy output to various types of fast X-ray transients. No measurable flux could be detected from CG 135+1, the COS B source which was in the FOV and therefore, we present 2 sigma upper flux limits on its spectral emission over the energy range 160 keV to 9.3 MeV.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 1994
- DOI:
- 10.1086/174412
- Bibcode:
- 1994ApJ...430..371B
- Keywords:
-
- Extraterrestrial Radiation;
- Gamma Ray Astronomy;
- Gamma Ray Spectra;
- Gamma Rays;
- Radiation Sources;
- Astronomical Spectroscopy;
- Balloon-Borne Instruments;
- Bremsstrahlung;
- Gamma Ray Telescopes;
- Photons;
- Spectral Emission;
- X Ray Sources;
- Astronomy;
- BALLOONS;
- GAMMA RAYS: OBSERVATIONS;
- RADIATION MECHANISMS: NONTHERMAL