The proto-black hole concept in GRB 101023 and its possible extension to GRB 110709B

A.V. PENACCHIONI; G.B. PISANI; R. RUFFINI; C.L. BIANCO; L. IZZO; M. MUCCINO

Munich

Conferencia; Gamma-Ray Bursts 2012; 2012

From the spectral analysis and the light curve of GRB 101023, a clear evidence of two spectral components has been outlined [1]. The first episode has been fit by a black body plus power- law spectral model. The temperature changes with time following a broken power-law. The second episode appears to be a canonical GRB. Using the Amati [2] and Atteia [3] relations we determined the cosmological redshift to be z = 0.9 ± 0.08 (stat.) ±0.2(sys.). This source appears to be a twin of GRB 090618 [4]: the first episode has been defined as the proto-black hole and the second one presents the characteristics of a canonical GRB. We are exploring the possibility to extend these considerations to GRB 110709B. GRB 110709B has been detected by Konus Wind and Swift [5] in gamma and X rays, and by Gemini and GROND telescopes in the optical bands. It is a very particular GRB, since Swift has triggered twice [7]. Its light curve presents a two-episode structure, one that begins 40 s before the trigtime and lasts ∼ 100 s, and another that starts 485 s after the trigtime and lasts ∼ 380 s. This separation between the two episodes is the largest seen up to date.