A universal scaling for short and long gamma-ray bursts: E_{X,iso}-E_{gamma,iso}-E_{pk}

摘要

The comprehensive statistical analysis of Swift X-ray light-curves,collecting data from six years of operation, revealed the existence of auniversal scaling among the isotropic energy emitted in the rest frame 10-10^4keV energy band during the prompt emission (E_{gamma,iso}), the peak of theprompt emission energy spectrum (E_{pk}), and the X-ray energy emitted in the0.3-10 keV observed energy band (E_{X,iso}). In this paper we show that thisthree-parameter correlation is robust and does not depend on our definition ofE_{X,iso}. It is shared by long, short, and low-energetic GRBs, differentlyfrom the well-known E_{gamma,iso}-E_{pk} correlation. We speculate that theultimate physical property that regulates the GRB properties is the outflowLorentz factor.