Konus-Wind Observations of the New Soft Gamma-Ray Repeater SGR 0501+4516
Abstract
In 2008 August, the new soft gamma-ray repeater SGR 0501+4516 was discovered by Swift. The source was soon confirmed by several groups in space- and ground-based multi-wavelength observations. In this Letter, we report the analysis of five short bursts from the recently discovered soft gamma-ray repeater (SGR), detected with the Konus-Wind gamma-ray burst spectrometer. Properties of the time histories of the observed events, as well as results of multichannel spectral analysis, both in the 20-300 keV energy range, show, that the source exhibits itself as a typical SGR. The bursts durations are lsim0.75 s and their spectra above 20 keV can be fitted by an optically thin thermal bremsstrahlung (OTTB) model with kT OTTB of 20-40 keV. The spectral evolution is observed, which resembles the SGR 1627-41 bursts, where a strong hardness-intensity correlation was noticed in the earlier Konus-Wind observations. The peak energy fluxes of all five events are comparable to the highest of those for known SGRs, so a less distant source is implied, consistent with the determined Galactic anticenter direction. Supposing the young supernova remnant HB9 (at the distance of 1.5 kpc) as a natal environment of the source, the peak luminosities of the bursts are estimated to be (2-5)×1040 erg s-1. The values of the total energy release, given the same assumptions, amount to (0.6-6)×1039 erg. These estimations of both parameters are typical for short SGR bursts.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 2009
- DOI:
- 10.1088/0004-637X/698/2/L82
- arXiv:
- arXiv:0902.3391
- Bibcode:
- 2009ApJ...698L..82A
- Keywords:
-
- gamma rays: bursts;
- gamma rays: observations;
- pulsars: individual: SGR 0501+4516;
- stars: neutron;
- Astrophysics - High Energy Astrophysical Phenomena;
- Astrophysics - Galaxy Astrophysics
- E-Print:
- 7 pages, 2 tables, 3 figures, ApJ Letters (accepted)