NASA Swift: GRB 060526: Continued emission for the Swift burst

TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 5163
SUBJECT: GRB 060526: Continued emission for the Swift burst
DATE: 06/05/26 17:26:29 GMT
FROM: Scott Barthelmy at NASA/GSFC Scott@lheamail.gsfc.nasa.gov

S. Campana (INAF-OAB), S. D. Barthelmy (GSFC), D. N. Burrows (PSU), N. Gehrels (NASA/GSFC), C. Guidorzi (Univ Bicocca&INAF-OAB), J. A. Kennea (PSU), F. E. Marshall (NASA/GSFC), K. M. McLean (LANL/UTD), A. Moretti (INAF-OAB), M. Stamatikos (NASA/ORAU), G. Tagliaferri (INAF-OAB) and D. E. Vanden Berk (PSU) report on behalf of the Swift Team:

Following up the report of the Swift GRB (Campana, et al., GCN 5162), we note that the BAT lightcurve shows a well separated second period of emission starting at ~T+220 sec and lasting until ~T+270 sec. The shape of the emission is FRED-like. Based on the 4-band TDRSS lightcurve, this second emission is significantly softer that the original emission at T+0.

Based on initial data we find a refined XRT position of RA(J2000): 15 31 18.27, DEC(J2000): +00 17 07.6, with an error radius of 4.3 arcsec (90% confidence) and 3 arcsec from the previously reported UVOT candidate position. The XRT light curve shows a sharp increase in the count rate starting around T+220 s from burst trigger, approximately coincident with the second BAT peak.

As shown in the table below, UVOT sees a fading afterglow in the four finding chart exposures for this burst. In the table, T is the time in seconds since the BAT trigger at the start of the exposure.

  T  Exposure Filter  Magnitude
  83  100     White    17.6
 188  400     V        17.2
 866  400     V        17.8
1274  100     White    18.4

We note that the location of this burst is ~11.3 hours from the Sun and therefore well suited for ground-based follow-ups. There is no bright galaxy at this location in the archived SDSS images. We will start receiving the full downlinked data set around 18:00 UT.