Short gamma-ray bursts (GRBs), typically lasting less than 2 s, are a special class of GRBs of great interest. We report the detection by the AGILE satellite of the short GRB 090510 which shows two clearly distinct emission phases: a prompt phase lasting similar to 200 ms and a second phase lasting tens of seconds. The prompt phase is relatively intense in the 0.3-10 MeV range with a spectrum characterized by a large peak/cutoff energy near 3 MeV; in this phase, no significant high-energy gamma-ray emission is detected. At the end of the prompt phase, intense gamma-ray emission above 30 MeV is detected showing a power-law time decay of the flux of the type t(-1.3) and a broadband spectrum remarkably different from that of the prompt phase. It extends from sub-MeV to hundreds of MeV energies with a photon index alpha similar or equal to 1.5. GRB 090510 provides the first case of a short GRB with delayed gamma-ray emission. We present the timing and spectral data of GRB 090510 and briefly discuss its remarkable properties within the current models of gamma-ray emission of short GRBs.
Agile Detection Of Delayed Gamma-Ray Emission From The Short Gamma-Ray Burst Grb 090510 / A., Giuliani; F., Fuschino; G., Vianello; M., Marisaldi; S., Mereghetti; M., Tavani; S., Cutini; G., Barbiellini; Longo, Francesco; E., Moretti; M., Feroci; E. D., Monte; A., Argan; A., Bulgarelli; P., Caraveo; P. W., Cattaneo; A. W., Chen; T., Contessi; F., D'Ammando; E., Costa; G. D., Paris; G. D., Cocco; I., Donnarumma; Y., Evangelista; A., Ferrari; M., Fiorini; M., Galli; F., Gianotti; C., Labanti; I., Lapshov; F., Lazzarotto; P., Lipari; A., Morselli; L., Pacciani; A., Pellizzoni; F., Perotti; G., Piano; P., Picozza; M., Pilia; G., Pucella; M., Prest; M., Rapisarda; A., Rappoldi; A., Rubini; S., Sabatini; E., Scalise; E., Striani; P., Soffitta; M., Trifoglio; A., Trois; E., Vallazza; S., Vercellone; V., Vittorini; A., Zambra; D., Zanello; C., Pittori; F., Verrecchia; P., Santolamazza; P., Giommi; S., Colafrancesco; L. A., Antonelli; L., Salotti. - In: THE ASTROPHYSICAL JOURNAL LETTERS. - ISSN 2041-8205. - STAMPA. - 708:(2010), pp. L84-L88. [10.1088/2041-8205/708/2/L84]
Agile Detection Of Delayed Gamma-Ray Emission From The Short Gamma-Ray Burst Grb 090510
LONGO, FRANCESCO;
2010-01-01
Abstract
Short gamma-ray bursts (GRBs), typically lasting less than 2 s, are a special class of GRBs of great interest. We report the detection by the AGILE satellite of the short GRB 090510 which shows two clearly distinct emission phases: a prompt phase lasting similar to 200 ms and a second phase lasting tens of seconds. The prompt phase is relatively intense in the 0.3-10 MeV range with a spectrum characterized by a large peak/cutoff energy near 3 MeV; in this phase, no significant high-energy gamma-ray emission is detected. At the end of the prompt phase, intense gamma-ray emission above 30 MeV is detected showing a power-law time decay of the flux of the type t(-1.3) and a broadband spectrum remarkably different from that of the prompt phase. It extends from sub-MeV to hundreds of MeV energies with a photon index alpha similar or equal to 1.5. GRB 090510 provides the first case of a short GRB with delayed gamma-ray emission. We present the timing and spectral data of GRB 090510 and briefly discuss its remarkable properties within the current models of gamma-ray emission of short GRBs.Pubblicazioni consigliate
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