BROADBAND TIME-RESOLVED E{sub p,i}-L{sub iso} CORRELATION IN GAMMA-RAY BURSTS
- Dipartimento di Fisica, Universita di Ferrara, Via Saragat 1, I-44100 Ferrara (Italy)
- INAF, Istituto di Astrofisica Spaziale e Fisica Cosmica, Bologna, Via Gobetti 101, I-40129 Bologna (Italy)
We report the results of a systematic study of the broadband (2-2000 keV) time-resolved prompt emission spectra of a sample of gamma-ray bursts (GRBs) detected with both Wide Field Cameras on board the BeppoSAX satellite and the BATSE experiment on board CGRO. In this first paper, we study the time-resolved dependence of the intrinsic peak energy E{sub p,i} of the E F(E) spectrum on the corresponding isotropic bolometric luminosity L{sub iso}. The E{sub p,i}-L{sub iso} relation or the equivalent relation between E{sub p,i} and the bolometric released energy E{sub iso}, derived using the time-averaged spectra of long GRBs with known redshift, is well established, but its physical origin is still a subject of discussion. In addition, some authors maintain that these relations are the result of instrumental selection effects. We find that not only a relation between the measured peak energy E{sub p} and the corresponding energy flux, but also a strong E{sub p,i} versus L{sub iso} correlation are found not only within each burst, but also are merging together the time-resolved data points from different GRBs. We do not expect significant instrumental selection effects that can affect the results obtained, apart from the fact that the GRBs in our sample are sufficiently bright to perform a time-resolved spectroscopy and that they have known redshift. If the fundamental physical process that gives rise to the GRB phenomenon does not depend on its brightness, we conclude that the E{sub p,i} versus L{sub iso} correlation found within each GRB is intrinsic to the emission process and that the correlations discovered by Amati et al. and Yonetoku et al. are likely not the result of selection effects. We also discuss the properties of the correlations found.
- OSTI ID:
- 22039200
- Journal Information:
- Astrophysical Journal, Vol. 754, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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