Optical Classification of Gamma-Ray Bursts in the Swift Era
Abstract
We propose a new method for the classification of optically dark gamma-ray bursts (GRBs), based on the X-ray and optical-to-X-ray spectral indices of GRB afterglows, and utilizing the spectral capabilities of Swift. This method depends less on model assumptions than previous methods, and can be used as a quick diagnostic tool to identify optically sub-luminous bursts. With this method we can also find GRBs that are extremely bright at optical wavelengths. We show that the previously suggested correlation between the optical darkness and the X-ray/gamma-ray brightness is merely an observational selection effect.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 2009
- DOI:
- 10.1088/0004-637X/699/2/1087
- arXiv:
- arXiv:0905.0524
- Bibcode:
- 2009ApJ...699.1087V
- Keywords:
-
- gamma rays: bursts;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 6 pages, 3 figures