TITLE: GCN CIRCULAR NUMBER: 20443 SUBJECT: GRB 170112A: Swift-BAT refined analysis DATE: 17/01/12 23:33:12 GMT FROM: Amy Lien at GSFC A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), N. Gehrels (GSFC), H. A. Krimm (NSF/USRA), C. B. Markwardt (GSFC), J. P. Norris (BSU), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-240 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 170112A (trigger #732188) (Mingo, et al., GCN Circ. 20436). The BAT ground-calculated position is RA, Dec = 15.232, -17.233 deg which is RA(J2000) = 01h 00m 55.7s Dec(J2000) = -17d 13' 57.9" with an uncertainty of 2.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%. The mask-weighted light curve shows a single-peaked structure that starts and peaks at ~T0, and ends at ~T+0.06 s. T90 (15-350 keV) is 0.06 +- 0.02 sec (estimated error including systematics). The time-averaged spectrum from T-0.00 to T+0.06 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.17 +- 0.34. The fluence in the 15-150 keV band is 1.3 +- 0.4 x 10^-8 erg/cm2. The 1-sec peak photon flux measured from T-0.47 sec in the 15-150 keV band is 0.3 +- 0.1 ph/cm2/sec. All the quoted errors are at the 90% confidence level. Using a 16-ms binned light curve, the lag analysis finds a lag of 19 (-17, +36) ms for the 100-350 keV to 25-50 keV, -7 (-12, +14) ms for the 50-100 keV to 15-25 keV band, and 0 (-7, +7) ms for the 50-100 keV to 25-50 keV. These values are consistent with those of a short GRB. Moreover, no extended emission are found. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/732188/BA/