Detection of the thermal component in GRB 160107A
Yamaoka, Kazutaka; Yoshida, Atsumasa; Sakamoto, Takanori; Nakahira, Satoshi; Serino, Motoko; Nakagawa, Yujin; Cherry, Michael L.; Mori, Masaki; Ricciarini, Sergio B.; Kawakubo, Yuta; Asaoka, Yoichi; Matsukawa, Shohei; Ozawa, Shunsuke; Penacchioni, Ana V.; Tezuka, Akira; Torii, Shoji; Yamada, Yusuke
Japan, United States, Italy
Abstract
We present the detection of a blackbody component in gamma-ray burst GRB 160107A emission by using the combined spectral data of the CALET Gamma-ray Burst Monitor (CGBM) and the MAXI Gas Slit Camera (GSC). MAXI/GSC detected the emission ∼45 s prior to the main burst episode observed by the CGBM. The MAXI/GSC and the CGBM spectrum of this prior emission period is fitted well by a blackbody with temperature 1.0^{+0.3}_{-0.2} keV plus a power law with a photon index of -1.6 ± 0.3. We discuss the radius of the photospheric emission and the main burst emission based on the observational properties. We stress the importance of coordinated observations via various instruments collecting high-quality data over a broad energy coverage in order to understand the GRB prompt emission mechanism.