TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5214 SUBJECT: GRB 060604: BAT refined analysis DATE: 06/06/05 01:50:02 GMT FROM: Jay R. Cummings at NASA/GSFC/Swift A. Parsons (GSFC), L. Barbier (GSFC), S. Barthelmy (GSFC), J. Cummings (GSFC/ORAU), E. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (BYU-Idaho), H. Krimm (GSFC/USRA), M. Koss (GSFC/UMD), C. Markwardt (GSFC/UMD), D. Palmer (LANL), T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/JSPS/USRA), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), on behalf of the Swift-BAT team: Using the data set from T-119.2 to T+182.9 sec from the recent telemetry downlink, we report further analysis of BAT GRB 060604 (trigger #213486) (Page, et al., GCN 5212). The BAT ground-calculated position is (RA,Dec) 337.233, -10.937 deg {22h 28m 55.8s, -10d 56' 14.8"} (J2000) +- 2.9 arcmin, (radius, sys+stat, 90% containment). The partial coding was 72%. The burst was very weak in BAT. There was some low-level soft emission over ~25 seconds starting at T-50, followed by the main peak at T+0. T90 (15-350 keV) is 10 +- 3 sec (estimated error including systematics). The time-averaged spectrum from T-1.4 to T+8.3 is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.90 +- 0.41. The fluence in the 15-150 keV band is 1.3 +- 0.3 x 10^-07 erg/cm2. The 1-sec peak photon flux measured from T+2.28 sec in the 15-150 keV band is 0.6 +- 0.1 ph/cm2/sec. All the quoted errors are at the 90% confidence level.