TITLE: GCN CIRCULAR NUMBER: 7692 SUBJECT: GRB 080506, Swift-BAT refined analysis DATE: 08/05/07 14:23:57 GMT FROM: Scott Barthelmy at NASA/GSFC K. McLean (GSFC/UMD), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+903 sec from recent telemetry downlinks, we report further analysis of BAT GRB 080506 (trigger #311159) (Baumgartner, et al., GCN Circ. 7685). The BAT ground-calculated position is RA, Dec = 329.467, 38.961 deg, which is RA(J2000) = 21h 57m 52.1s Dec(J2000) = +38d 57' 40.0" with an uncertainty of 2.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 60%. The mask-weighted light curve shows two episodes of emission, the first starting at ~T+20 sec, peaking at ~T+40 sec, and returning to background at ~T+90 sec. The second episode starts at ~T+100 sec, peaks at ~T+150 sec, and ends at ~T+200 sec. T90 (15-350 keV) is 150 +- 20 sec (estimated error including systematics). The time-averaged spectrum from T+25.8 to T+188.8 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.87 +- 0.19. The fluence in the 15-150 keV band is 1.3 +- 0.2 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+134.48 sec in the 15-150 keV band is 0.4 +- 0.1 ph/cm2/sec. 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/311159/BA/ This burst satisfies Sakamoto/Ukwatta Swift-BAT possible high-z criteria (Ukwatta et al. arXiv:0802.3815): 1) PL photon index = 1.87 (PL photon index < 2) 2) 1-s peak photon flux = 0.4 (1-s peak photon flux < 1.0 ph/cm2/s) 3) Light curve variance = 6.2x10-6 (Variance < 0.0001) 4) T90/(Peak photon flux) = 403 (T90/(Peak photon flux) > 100) Based on a limited sample of bursts, these criteria yield an 85% chance it has a redshift greater than 3.5.