Discovery of intense X-ray bursts from the globular cluster NGC 6624.
Abstract
A new type of time variation of cosmic X-ray sources has been found from the Astronomical Netherlands Satellite (ANS) observations of the source 3U 1820-30, associated with the globular cluster NGC 6624. Two bursts in the 1-30 keV X-ray intensity of this source are reported. Each displayed a rapid rise in flux (no more than 1 s) by a factor of 20-30 followed by an approximately 8-s exponential decay. These bursts appear to be qualitatively different from short time variations previously reported for X-ray sources. Analysis for further source variability, energy spectra, and position is presented. The characteristics of these events may imply the existence of a collapsed core in the globular cluster.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 1976
- DOI:
- 10.1086/182105
- Bibcode:
- 1976ApJ...205L.127G
- Keywords:
-
- Black Holes (Astronomy);
- Globular Clusters;
- Satellite Observation;
- X Ray Sources;
- Astronomical Models;
- Astronomical Netherlands Satellite;
- Cosmic Rays;
- Energy Spectra;
- Radiant Flux Density;
- Spaceborne Astronomy;
- Astrophysics