TITLE: GCN CIRCULAR NUMBER: 43493 SUBJECT: GRB 260120B: Swift-BAT refined analysis DATE: 26/01/21 23:08:12 GMT FROM: D. R. Sadaula at NASA GSFC <dev.r.sadaula@nasa.gov> D. M. Palmer (LANL), S. D. Barthelmy (GSFC), R. Gupta (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), M. J. Moss (GSFC), T. Parsotan (GSFC), D. Sadaula (GSFC/UMBC), T. Sakamoto (AGU) (i.e. the Swift-BAT team): Using the data set from T-769 to T+303 sec from the recent telemetry downlink, we report further analysis of BAT GRB 260120B (trigger #1442454) (Ferro et al., GCN Circ. 43479). The BAT ground-calculated position is RA, Dec = 284.701, 61.905 deg which is RA(J2000) = 18h 58m 48.3s Dec(J2000) = +61d 54' 19.2" with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 9%. The BAT light curve showed a single-peaked structure with a duration of about 10 sec. T90 (15-350 keV) is 4.48 +- 0.94 sec (estimated error including systematics). The time-averaged spectrum from T-0.34 to T+4.59 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index -0.93 +- 1.35, and Epeak of 103.9 +- 38.6 keV (chi squared 48.41 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 1.2 +- 0.1 x 10^-06 erg/cm2 and the 1-sec peak flux measured from T+0.48 sec in the 15-150 keV band is 3.1 +- 0.8 ph/cm2/sec. A fit to a simple power law gives a photon index of 0.95 +- 0.21 (chi squared 57.22 for 57 d.o.f.). All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1442454 View this GCN Circular online at https://gcn.nasa.gov/circulars/43493. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...