A tight correlation for GRB afterglows with 'canonical' light curves

摘要

Gamma -ray bursts (GRBs) observed up to redshifts z > 8 are fascinating objects to study due to their still unexplained relativistic outburst mechanisms and a possible use to test cosmological models. Our analysis of 77 GRB afterglows with known redshifts revealed a physical subsample of long GRBs with canonical plateau breaking to power-law light curves with a significant luminosity L_(X)~(*) -break time T_(a)~(*) correlation in the GRB rest frame. This subsample forms approximately the upper envelope of the studied distribution. It proves that within the full sample of afterglows there exist physical subclasses revealed here by tight correlations of their afterglow properties. The afterglows with regular ("canonical") light curves obey not only a mentioned tight physical scaling, but -for a given T_(a)~(*) - the more regular progenitor explosions occur, the brighter afterglows result.