Gamma-ray Burst 100928A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN/BACODINE POSITION NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Tue 28 Sep 10 02:20:32 UT
  NOTICE_TYPE:     Swift-BAT GRB Position
  TRIGGER_NUM:     435160,   Seg_Num: 0
  GRB_RA:          223.036d {+14h 52m 09s} (J2000),
                   223.196d {+14h 52m 47s} (current),
                   222.294d {+14h 49m 10s} (1950)
  GRB_DEC:         -28.561d {-28d 33' 39"} (J2000),
                   -28.605d {-28d 36' 16"} (current),
                   -28.356d {-28d 21' 22"} (1950)
  GRB_ERROR:       3.00 [arcmin radius, statistical only]
  GRB_INTEN:       16119 [cnts]    Image_Peak=229 [image_cnts]
  TRIGGER_DUR:     4.096 [sec] 
  TRIGGER_INDEX:   300     E_range: 25-100 keV
  BKG_INTEN:       149326 [cnts]
  BKG_TIME:        8337.78 SOD {02:18:57.78} UT
  BKG_DUR:         40 [sec]
  GRB_DATE:        15467 TJD;   271 DOY;   10/09/28
  GRB_TIME:        8392.75 SOD {02:19:52.75} UT
  GRB_PHI:         -93.19 [deg]
  GRB_THETA:        37.75 [deg]
  SOLN_STATUS:     0x83
  RATE_SIGNIF:     9.16 [sigma]
  IMAGE_SIGNIF:    6.79 [sigma]
  MERIT_PARAMS:     +1  +0  +0  +2  +2  -3 -100  +0 -70  +0 
  SUN_POSTN:       184.46d {+12h 17m 51s}   -1.93d {-01d 55' 50"}
  SUN_DIST:         45.53 [deg]   Sun_angle= -2.6 [hr] (East of Sun)
  MOON_POSTN:       55.03d {+03h 40m 06s}  +22.84d {+22d 50' 06"}
  MOON_DIST:       167.89 [deg]
  MOON_ILLUM:      80 [%]
  GAL_COORDS:      332.71, 27.24 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      229.06,-11.55 [deg] ecliptic lon,lat of the burst (or transient)
  COMMENTS:        SWIFT-BAT GRB Coordinates.  
  COMMENTS:        This is a rate trigger.  
  COMMENTS:        A point_source was found.  
  COMMENTS:        This does not match any source in the on-board catalog.  
  COMMENTS:        This does not match any source in the ground catalog.  
  COMMENTS:        This is a GRB.  
  COMMENTS:        Since the IMAGE_SIGNIF is less than 7 sigma, this is a questionable detection.  
  COMMENTS:        This trigger occurred at longitude,latitude = 213.25,10.48 [deg].  
  

• red DSS finding chart ps-file
  
  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Tue 28 Sep 10 02:23:25 UT
  NOTICE_TYPE:     Swift-BAT GRB Lightcurve
  TRIGGER_NUM:     435160,   Seg_Num: 0
  GRB_RA:          223.036d {+14h 52m 09s} (J2000),
                   223.196d {+14h 52m 47s} (current),
                   222.294d {+14h 49m 10s} (1950)
  GRB_DEC:         -28.561d {-28d 33' 39"} (J2000),
                   -28.605d {-28d 36' 16"} (current),
                   -28.356d {-28d 21' 22"} (1950)
  GRB_DATE:        15467 TJD;   271 DOY;   10/09/28
  GRB_TIME:        8392.75 SOD {02:19:52.75} UT
  TRIGGER_INDEX:   300
  GRB_PHI:         -93.19 [deg]
  GRB_THETA:        37.75 [deg]
  DELTA_TIME:      -56.00 [sec]
  TRIGGER_DUR:     4.096 [sec] 
  SOLN_STATUS:     0x83
  RATE_SIGNIF:     9.16 [sigma]
  IMAGE_SIGNIF:    6.79 [sigma]
  LC_URL:          sw00435160000msb.lc
  SUN_POSTN:       184.46d {+12h 17m 51s}   -1.93d {-01d 55' 53"}
  SUN_DIST:         45.52 [deg]   Sun_angle= -2.6 [hr] (East of Sun)
  MOON_POSTN:       55.05d {+03h 40m 13s}  +22.84d {+22d 50' 21"}
  MOON_DIST:       167.87 [deg]
  MOON_ILLUM:      80 [%]
  GAL_COORDS:      332.71, 27.24 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      229.06,-11.55 [deg] ecliptic lon,lat of the burst (or transient)
  COMMENTS:        SWIFT-BAT GRB Lightcurve.  
  COMMENTS:           
  COMMENTS:        The next comments were copied from the BAT_POS Notice:  
  COMMENTS:        This is a rate trigger.  
  COMMENTS:        A point_source was found.  
  COMMENTS:        This does not match any source in the on-board catalog.  
  COMMENTS:        This does not match any source in the ground catalog.  
  COMMENTS:        This is a GRB.  
  COMMENTS:        Since the IMAGE_SIGNIF is less than 7 sigma, this is a questionable detection.  
  COMMENTS:        This trigger occurred at longitude,latitude = 213.25,10.48 [deg].  
  

  
• GCN Circular #11310
  V. D'Elia (ASDC), S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU), H. A. Krimm (CRESST/GSFC/USRA), C. B. Markwardt (NASA/GSFC), M. H. Siegel (PSU), M. Stamatikos (OSU/NASA/GSFC), G. Stratta (ASDC) and E. Troja (NASA/GSFC/ORAU) report on behalf of the Swift Team:
  At 02:19:52 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 100928A (trigger=435160). The BAT on-board calculated location is RA, Dec 223.036, -28.561 which is

     RA(J2000) = 14h 52m 09s
     Dec(J2000) = -28d 33' 39"
  

  with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single-peaked structure with a duration of about 6 sec. The peak count rate was ~700 counts/sec (15-350 keV), at ~1 sec after the trigger. There may be additional emission at T+180 sec.
  Due to an Sun observing constraint, Swift cannot slew to the BAT position until 20:05 UT on 2010 December 26. There will thus be no XRT or UVOT data for this trigger.
  Burst Advocate for this burst is V. D'Elia (delia AT asdc.asi.it). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)
• GCN Circular #11312
  H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), V. D'Elia (ASDC), E. E. Fenimore (LANL), N. Gehrels (GSFC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team):
  Using the data set from T-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 100928A (trigger #435160) (D'Elia, et al., GCN Circ. 11310). The BAT ground-calculated position is RA, Dec = 223.037, -28.542 deg which is

      RA(J2000)  =  14h 52m 09.0s
      Dec(J2000) = -28d 32' 32.5"
  

  with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 15%.
  The mask-weighted light curve showed a single peak starting at T-1 with a total duration of ~6 seconds. T90 (15-350 keV) is 3.3 +- 0.6 sec (estimated error including systematics).
  The time-averaged spectrum from T+0.9 to T+4.4 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.79 +- 0.29. The fluence in the 15-150 keV band is 3.5 +- 0.6 x 10-7 erg/cm2. The 1-sec peak photon flux measured from T+1.31 sec in the 15-150 keV band is 2.5 +- 0.5 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/435160/BA/
• GCN Report 309.1
  GCN_Report 309.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_309_1.pdf by V. D Elia at ASDC titled: "Final report on Swift Observations of GRB 100928A"