A new procedure for smoothing a gamma-ray burst (GRB) light curve and calculating its variability is presented. Applying the procedure to a sample of 25 long GRBs, we have obtained a very tight correlation between the variability and the peak luminosity. The only significant outlier in the sample is GRB 030329. With this outlier excluded, the data scatter is reduced by a factor of ~3 compared to that of Guidorzi et al., measured by the deviation of fit. Possible causes for the outlier are discussed.
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- February 2006
- methods: data analysis;
- gamma-rays: bursts;
- 9 pages, including 7 figure. Expanded as requested by referee. An error in Fig. 1 was corrected (the two 1-sigma lines in the old version were wrong). Accepted for publication by MNRAS