2005/04/30 by Enwei Liang, Bing Zhang · 1 citation
Physics and Astronomy · #astro-ph
paper · pdf · doi:10.1086/491594
published as Astrophys.J.633:611-623,2005 · 10 pages (emulateapj) plus 12 figures, accepted for publication in ApJ
arxiv created 2005/07/23 · arxiv updated 2009/12/01
We present a multi-variable regression analysis to several observable quantities for a sample of 15 gamma-ray bursts (GRBs). The observables used in the analysis includes the isotropic gamma-ray energy (Egamma,iso), the peak energy of the nu Fnu spectrum in the rest frame (Ep'), and the rest frame break time of the optical afterglow light curves(tb'). A strong dependence of E_gamma, iso on Ep' and tb' is derived. We also extend the analysis to the isotropic afterglow energies in the X-ray and the optical bands, respectively, and find that they are essentially not correlated with Ep' and tb'. Regarding the E_gamma, iso(Ep', tb') relationship as a luminosity indicator, we explore the possible constraints on the cosmological parameters using the GRB sample. Our results indicate 0.13<omegaM<0.49 and 0.50<OmegaLambda<0.85 for a flat Universe. The decelerating factor and its cosmological evolution, and the transition redshift are also investigated. Through Monte Carlo simulations, we find that the GRB sample satisfying our relationship observationally tends to be a soft and bright one, and that the contraints on the cosmological parameters can be much improved either by the enlargement of the sample size or by the increase of the observational precision. Furthermore, the detections of a few high redshift GRBs satisfying the correlation could greatly tighten the constraints (abridged).