TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4606 SUBJECT: GRB060105: refined analysis of the Suzaku observation DATE: 06/01/27 14:52:24 GMT FROM: Kazuhiro Nakazawa at ISAS/JAXA K. Nakazawa (ISAS/JAXA), K. Yamaoka , Y. Nakagawa (AGU), M. Yamauchi, E. Sonoda, S. Maeno (Univ. of Miyazaki), T. Murakami, D. Yonetoku (Kanazawa U.), M. Tashiro, K. Abe, K. Onda (Saitama U.), N. Ishikawa, A. Yoshida (AGU), N. Yamasaki, Y. Terashima, H. Murakami (ISAS/JAXA), K. Torii (Osaka U.), Y. Ichikawa, S. Murasawa, R. Fujimoto (ISAS/JAXA), Tatsuya Inui (Kyoto U.), on behalf of Suzaku GRB ToO team report: We have carried out refined analysis on the data from the Suzaku TOO observation of GRB060105 (Ziaeepour et al. GCN4429). The Suzaku observation started on 2006, January 5 at 12:10 UT, 5 hours 20 minutes after the GRB, and ended on January 6, at 12:00 UT. A good exposure of 35 ks was obtained in total. As reported by Mitsuda et al (GCN4449), the afterglow of GRB060105 is clearly detected in the XIS images and its position is fully consistent with the refined Swift/XRT one (Godet et al., GCN4433). Suzaku XIS spectra ranging 0.5-8 keV are well described with an absorbed power law model. The derived best fit photon index and column density are Gamma = 2.1+/- 0.1 and NH = (3.0 +/- 0.6) x 10^21 cm^-2, respectively. No signature of spectral variability is detected during the observation. The flux fades along the Suzaku observation from (1.9 +/- 0.3) x 10^-12 erg/s/cm2 (T_burst + 5.7-7.0 hours) to (1.5 +/- 0.5) x 10^-13 erg/s/cm2 (T_burst + 26-28 hours) in the 2-10 keV energy band. Decay index was found to be -1.3 +/- 0.2. Note that a possible 10% systematic calibration error is not included in the errors quoted above. These results are generally consistent with those obtained by analyzing the Swift/XRT data.