GRB4 - GRB Observations by SWIFT |
Speaker_ |
Bianco, Carlo Luciano |
Co-autors |
Remo Ruffini |
Talk _ |
The fireshell model in the Swift era |
Abstract _ |
We have recently obtained the exact analytic solutions of the relativistic equations relating the radial and time coordinate of a relativistic thin uniform shell expanding in the interstellar medium in the fully radiative and fully adiabatic regimes [ApJ 633 (2005) L13]. Applying these solutions to the Gamma-Ray Burst (GRB) afterglows, we determined the corresponding exact analytic expressions of the EQuiTemporal Surfaces (EQTSs) of the observed radiation [ApJ 620 (2005) L23]. Assuming that such radiation is not emitted in spherical symmetry but is confined into a narrow jet, we also determined the exact analytic expressions to compute the value of the detector arrival time at which we start to "see" the sides of the jet [ApJ, in press, astro-ph/0605332]. We compare and contrast these results with the corresponding approximate relations usually adopted in the GRB literature. The importance of using the exact solutions instead of the approximate ones in the interpretation of the Swift data is discussed. |