TITLE: GCN CIRCULAR NUMBER: 12082 SUBJECT: SGR 1E 1841-045: Swift-BAT refined analysis DATE: 11/06/23 18:12:20 GMT FROM: Scott Barthelmy at NASA/GSFC H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), A. Rowlinson (U Leicester), T. Sakamoto (GSFC/UMBC), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+302 sec from the recent telemetry downlink, we report further analysis of event from SGR 1E 1841-045 (trigger #455904) (Rowlinson, et al., GCN Circ. 12079). The BAT ground-calculated position is RA, Dec = 280.329, -4.934 deg, which is RA(J2000) = 18h 41m 19.0s Dec(J2000) = -04d 56' 00.9" with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 18%. The mask-weighted light curve shows a single spike that starts at ~T_zero and ends at ~T+0.04 sec. T90 (15-350 keV) is 0.020 +- 0.009 sec (estimated error including systematics). The time-averaged spectrum from T-0.0 to T+0.1 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 0.04 +- 0.91, and Epeak of 32.8 +- 4.7 keV (chi squared 43.0 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 1.6 +- 0.2 x 10^-7 erg/cm2 and the 1-sec peak flux measured from T-0.43 sec in the 15-150 keV band is 3.6 +- 0.5 ph/cm2/sec. A fit to a simple power law gives a photon index of 2.68 +- 0.15 (chi squared 85.2 for 57 d.o.f.). All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/455904/BA/