A γ-ray burst preceded by X-ray activity
Abstract
GAMMA-RAY bursts remain mysterious astrophysical phenomena. The discovery of cyclotron harmonics1-3 in their spectra is strong evidence that they originate from strongly magnetized neutron stars, but their energy source and photon production mechanism are unknown. In observations of a γ-ray burst using the Ginga astronomy satellite, we detected X-ray emission in the 2-10 keV energy range ~10 s before the onset of the γ-ray event, as well as a tail of X-ray emission for ~30 s afterwards. The long timescale and near black-body spectrum of the precursory X-ray emission suggests that the burst mechanism involves a transition from thermal to non-thermal photon production, and that the energy source for the burst comes from within the neutron star rather than from accretion.
- Publication:
-
Nature
- Pub Date:
- April 1991
- DOI:
- 10.1038/350592a0
- Bibcode:
- 1991Natur.350..592M
- Keywords:
-
- Gamma Ray Bursts;
- Neutron Stars;
- Stellar Activity;
- X Ray Spectra;
- Bremsstrahlung;
- Gamma Ray Spectra;
- Japanese Spacecraft;
- Spaceborne Astronomy;
- Space Radiation