Evidence for a late-time outburst of the X-ray afterglow of GB970508 from BeppoSAX
Abstract
The gamma -ray burst GB970508 was observed simultaneously by the Gamma Ray Burst Monitor (GRBM) and one of the X-ray Wide Field Cameras (WFC) aboard BeppoSAX. The latter provided a position within 1.9' radius. A series of follow-up observations with the Narrow Field Intruments (NFI) was then performed in a period from ~ 6 hours to 6 days after the main event. A previously unknown source, which we associate with the afterglow of the GRB, was discovered in the error box. We find that, after the initial burst, X-ray emission is still present and decays as ~ t(-1.1) up to ~ 6x 10(4) s. This is followed by a burst of activity with a duration ~ 10(5) s. The energy produced in this event is a substantial fraction of the total energy of the GRB, which means that the afterglow is not a remnant of the initial burst (the GRB) that fades away smoothly. Our results support the idea that the processes generating the GRB and its afterglow are the same.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- March 1998
- DOI:
- 10.48550/arXiv.astro-ph/9710355
- arXiv:
- arXiv:astro-ph/9710355
- Bibcode:
- 1998A&A...331L..41P
- Keywords:
-
- GAMMA RAYS: BURSTS;
- X-RAYS: BURSTS;
- Astrophysics
- E-Print:
- 5 pages, LaTeX, 4 postscript figures