| Issue |
EAS Publications Series
Volume 61, 2013
Gamma-ray Bursts: 15 Years of GRB Afterglows – Progenitors, Environments and Host Galaxies from the Nearby to the Early Universe
|
|
|---|---|---|
| Page(s) | 271 - 273 | |
| Section | Chapter V: Afterglow Emission-I Long GRBs (Observations) | |
| DOI | https://doi.org/10.1051/eas/1361043 | |
| Published online | 22 July 2013 | |
A.J. Castro-Tirado, J.Gorosabel and I.H. Park (eds)
EAS Publications Series, 61 (2013) 271-273
Color indices of optical afterglows of long GRBs in the Swift era
1 Astronomical Institute,
AS CR,
25165
Ondřejov, Czech
Republic
2 Czech Technical University in Prague, FEL, Prague, Czech Republic
3 INAF/IASF Bologna, via Gobetti 101,
40129
Bologna,
Italy
We show the power of the method of the color indices that uses the commonly available multiband photometry of optical afterglows (OAs) of long GRBs detected by Swift. Our study shows that for most OAs, in the observer frame, these colors, corrected for the Galactic reddening, display prominent clustering in the color-color diagrams. The color indices enable us to distinguish OAs from other types of objects even without available gamma-ray emission. The color-color diagrams can be used to assess the extinction inside the host galaxy. Our approach is also generally important for investigating the numerous faint OAs for which obtaining spectra with good S/N ratio is often impossible.
© EAS, EDP Sciences 2013