Using GRB 991216 as a prototype, we show that the intensity substructures observed in what is generally called the "prompt emission" in gamma-ray bursts (GRBs) do originate in the collision between the accelerated baryonic matter pulse with inhomogeneities in the interstellar medium (ISM). The initial phase of such process occurs at a Lorentz factor gamma similar to 310. The crossing of ISM inhomogeneities of sizes occurs in a DeltaR similar to 10(15) cm detector arrival time interval of similar to0.4 s, implying an apparent superluminal behavior of similar to10(5)c. The long-lasting debate between the validity of the external shock model versus the internal shock model for GRBs is solved in favor of the first.
On the structures in the afterglow peak emission of gamma-ray bursts / Ruffini, Remo; Bianco, Carlo Luciano; Pascal, Chardonnet; Federico, Fraschetti; She Sheng, Xue. - In: THE ASTROPHYSICAL JOURNAL. - ISSN 0004-637X. - STAMPA. - 581:1 II(2002), pp. L19-L22. [10.1086/345804]
On the structures in the afterglow peak emission of gamma-ray bursts
RUFFINI, Remo;BIANCO, Carlo Luciano;
2002
Abstract
Using GRB 991216 as a prototype, we show that the intensity substructures observed in what is generally called the "prompt emission" in gamma-ray bursts (GRBs) do originate in the collision between the accelerated baryonic matter pulse with inhomogeneities in the interstellar medium (ISM). The initial phase of such process occurs at a Lorentz factor gamma similar to 310. The crossing of ISM inhomogeneities of sizes occurs in a DeltaR similar to 10(15) cm detector arrival time interval of similar to0.4 s, implying an apparent superluminal behavior of similar to10(5)c. The long-lasting debate between the validity of the external shock model versus the internal shock model for GRBs is solved in favor of the first.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
