Spectral Cross-Calibration of the Konus-Wind, the Suzaku/WAM, and the Swift/BAT Data Using Gamma-Ray Bursts
Abstract
We report on the spectral cross-calibration results of the Konus-Wind, the Suzaku/WAM, and the Swift/BAT instruments using simultaneously observed gamma-ray bursts (GRBs). This is the first attempt to use simultaneously observed GRBs as a spectral calibration source to understand systematic problems among the instruments. Based on these joint spectral fits, we find that (1) although a constant factor (a normalization factor) agrees within 20% among the instruments, the BAT constant factor shows a systematically smaller value by 10%-20% compared to that of Konus-Wind, (2) there is a systematic trend that the low-energy photon index becomes steeper by 0.1-0.2 and Epeak becomes systematically higher by 10%-20% when including the BAT data in the joint fits, and (3) the high-energy photon index agrees within 0.2 among the instruments. Our results show that cross-calibration based on joint spectral analysis is an important step to understanding the instrumental effects that could be affecting the scientific results from the GRB prompt emission data.
- Publication:
-
Publications of the Astronomical Society of Japan
- Pub Date:
- February 2011
- DOI:
- 10.1093/pasj/63.1.215
- arXiv:
- arXiv:1011.1301
- Bibcode:
- 2011PASJ...63..215S
- Keywords:
-
- gamma rays: burst;
- gamma rays: observations;
- instrumentation: detectors;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 82 pages, 88 figures, accepted for publication in PASJ