X-ray afterglow light curves: Toward a standard candle?

B. Gendre, A. Galli, M. Boer

Research output: Chapter in Book/Conference paperConference paper


We investigate the clustering of afterglow light curves observed at X-ray and optical wavelengths. We construct a sample of 34 bursts with known distance and X-ray afterglow. We correct the light curves for cosmological effects and compare the observed X-ray fluxes one day after the burst. We check for correlations between the observed flux and the burst spectral and temporal properties. We confirm the previous result of Boer and Gendre (2000) that X-ray afterglow light curves cluster in luminosity, even when we consider the SWIFT data. We observe this clustering only for the afterglow light curves; the inclusion of prompt-related data broaden the distribution. The same clustering is observed for the optical light curves; GRB sources can be divided in three classes, namely optical and X-ray bright afterglows, optical and X-ray dim ones, and optically bright -X-ray dim ones. We argue that this clustering is related to the fireball total energy, the external medium density, the fraction of fireball energy going in relativistic electrons and magnetic fields. These parameters can be either fixed to a standard value, or correlated.

Original languageEnglish
Title of host publicationGAMMA-RAY BURSTS 2007
EditorsM Galassi, D Palmer, E Fenimore
Number of pages2
ISBN (Print)978-0-7354-0533-2
Publication statusPublished - 2008
Externally publishedYes
EventSanta Fe Conference on Gamma-Ray Bursts - Santa Fe
Duration: 5 Nov 20079 Nov 2007

Publication series

NameAIP Conference Proceedings
ISSN (Print)0094-243X


ConferenceSanta Fe Conference on Gamma-Ray Bursts
CitySanta Fe

Cite this

Gendre, B., Galli, A., & Boer, M. (2008). X-ray afterglow light curves: Toward a standard candle? In M. Galassi, D. Palmer, & E. Fenimore (Eds.), GAMMA-RAY BURSTS 2007 (pp. 72-+). (AIP Conference Proceedings; Vol. 1000). ACOUSTICAL SOC AMER AMER INST PHYSICS.