TITLE: GCN CIRCULAR NUMBER: 16029 SUBJECT: GRB 140323A: Swift-BAT refined analysis DATE: 14/03/23 19:27:36 GMT FROM: Hans Krimm at NASA-GSFC T. Sakamoto (AGU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), M. Stamatikos (OSU), E. Troja (NASA/GSFC/UMCP), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+693 sec from the recent telemetry downlink, we report further analysis of BAT GRB 140323A (trigger #592916) (Troja, et al., GCN Circ. 16027). The BAT ground-calculated position is RA, Dec = 356.975, -79.916 deg which is RA(J2000) = 23h 47m 54.1s Dec(J2000) = -79d 54' 57.3" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 12%. The mask-weighted light curve shows a complex structure. Low-level emission starts around T-60 sec, then the first episode runs from T-20 to T+55 sec, and is a slow rise and fall with multiple sub-peaks superimposed. The second episode has a similar shape and runs from T+60 to T+110 sec, followed by more low-level emission out to T+140 sec. The second episode is spectrally softer than the first. T90 (15-350 keV) is 104.9 +- 2.6 sec (estimated error including systematics). The time-averaged spectrum from T-7.09 to T+117.37 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 1.35 +- 0.17, and Epeak of 127.1 +- 59.2 keV (chi squared 50.15 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 1.6 +- 0.0 x 10^-05 erg/cm2 and the 1-sec peak flux measured from T+6.42 sec in the 15-150 keV band is 6.2 +- 0.7 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.64 +- 0.04 (chi squared 59.02 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/592916/BA/