Relatore
Descrizione
Accurate modeling of the early X-ray emission in short gamma-ray bursts (GRBs) is essential for probing the GRB engine, understanding jet physics, and improving electromagnetic follow-up of gravitational wave signals from binary neutron star mergers in the context of multi-messenger astronomy.
Thanks to the operation of the Swift satellite over the last 20 years, we now have access to an extensive archive of GRB X-ray observations. The early X-ray light curves often exhibit a bright and steep decay phase, whose physical origin remains poorly understood. In short GRBs, this phase is particularly prominent, as their fainter forward-shock emission makes the steep decay detectable for up to 15 minutes.
In this talk, I will present our systematic analysis of the early X-ray emission of short GRBs, including both the temporal and spectral evolution. We introduce a new modeling technique that accounts for both the curvature and the intrinsic evolution of the GRB spectrum in Swift/XRT and Swift/BAT data. This approach enables us to track the evolution of spectral peak energy and the bolometric flux during the steep decay phase. Our study reveals a tight correlation between the peak energy and the isotropic equivalent luminosity. This relation enables us to infer the intrinsic properties of short GRBs and assess the detectability of their early X-ray emission with wide-field X-ray cameras. In particular, our work can help to interpret the nature of some fast X-ray transients detected by Einstein Probe and suggest observational multi-messenger strategies.
| Sessione | Onde Gravitazionali e astronomia multimessaggera |
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