Observations of the Prompt Gamma-Ray Emission of GRB 070125
Yamaoka, Kazutaka; Hong, Soojing; Kodaka, Natsuki; Nakagawa, Yujin E.; Ohno, Masanori; Onda, Kaori; Sugita, Satoshi; Urata, Yuji; Hurley, Kevin; Pal'shin, Valentin; Bellm, Eric C.; Boggs, Steven E.; Tashiro, Makoto; Mitrofanov, I. G.; Kozyrev, A. S.; Litvak, M. L.; Sanin, A. B.; Bandstra, Mark S.; Tretyakov, V. I.; Wigger, Claudia
United States, Russia, Japan, Switzerland
Abstract
The long, bright gamma-ray burst GRB 070125 was localized by the Interplanetary Network. We present light curves of the prompt gamma-ray emission as observed by Konus-Wind, RHESSI, Suzaku WAM, and Swift BAT. We detail the results of joint spectral fits with Konus and RHESSI data. The burst shows moderate hard-to-soft evolution in its multipeaked emission over a period of about 1 minute. The total burst fluence as observed by Konus is 1.79 × 10-4 ergs cm-2 (20 keV-10 MeV). Using the spectroscopic redshift z = 1.548, we find that the burst is consistent with the "Amati" Epeak,i - Eiso correlation. Assuming a jet opening angle derived from broadband modeling of the burst afterglow, GRB 070125 is a significant outlier to the "Ghirlanda" Epeak,i - Eγ correlation. Its collimation-corrected energy release, Eγ = 2.5 × 1052 ergs, is the largest yet observed.