Gamma-ray Burst 071001

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN/BACODINE POSITION NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Mon 01 Oct 07 16:32:29 UT
  NOTICE_TYPE:     Swift-BAT GRB Position
  TRIGGER_NUM:     292826,   Seg_Num: 0
  GRB_RA:          149.766d {+09h 59m 04s} (J2000),
                   149.828d {+09h 59m 19s} (current),
                   149.366d {+09h 57m 28s} (1950)
  GRB_DEC:         -59.751d {-59d 45' 02"} (J2000),
                   -59.788d {-59d 47' 16"} (current),
                   -59.511d {-59d 30' 38"} (1950)
  GRB_ERROR:       3.00 [arcmin radius, statistical only]
  GRB_INTEN:       10796 [cnts]    Image_Peak=296 [image_cnts]
  TRIGGER_DUR:     2.048 [sec] 
  TRIGGER_INDEX:   443     E_range: 15-50 keV
  BKG_INTEN:       112541 [cnts]
  BKG_TIME:        59469.73 SOD {16:31:09.73} UT
  BKG_DUR:         24 [sec]
  GRB_DATE:        14374 TJD;   274 DOY;   07/10/01
  GRB_TIME:        59508.07 SOD {16:31:48.07} UT
  GRB_PHI:          63.36 [deg]
  GRB_THETA:        14.82 [deg]
  SOLN_STATUS:     0x403
  RATE_SIGNIF:     12.80 [sigma]
  IMAGE_SIGNIF:    7.13 [sigma]
  MERIT_PARAMS:     +1  +0  +0  +2  +1  +5  +0  +1 -44  +1 
  SUN_POSTN:       187.46d {+12h 29m 50s}   -3.22d {-03d 13' 11"}
  SUN_DIST:         63.49 [deg]   Sun_angle= 2.5 [hr] (West of Sun)
  MOON_POSTN:       73.65d {+04h 54m 36s}  +27.78d {+27d 46' 55"}
  MOON_DIST:       107.24 [deg]
  MOON_ILLUM:      69 [%]
  GAL_COORDS:      282.75, -3.81 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      194.29,-63.31 [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:        This trigger occurred at longitude,latitude = 242.31,-10.43 [deg].  
  COMMENTS:           
  COMMENTS:        This trigger occured while the StarTracker had lost lock, so it is possibly bogus.  
  

• red DSS finding chart ps-file
  
  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Mon 01 Oct 07 16:35:31 UT
  NOTICE_TYPE:     Swift-BAT GRB Lightcurve
  TRIGGER_NUM:     292826,   Seg_Num: 0
  GRB_RA:          149.766d {+09h 59m 04s} (J2000),
                   149.828d {+09h 59m 19s} (current),
                   149.366d {+09h 57m 28s} (1950)
  GRB_DEC:         -59.751d {-59d 45' 02"} (J2000),
                   -59.788d {-59d 47' 16"} (current),
                   -59.511d {-59d 30' 38"} (1950)
  GRB_DATE:        14374 TJD;   274 DOY;   07/10/01
  GRB_TIME:        59508.07 SOD {16:31:48.07} UT
  TRIGGER_INDEX:   443
  GRB_PHI:          63.36 [deg]
  GRB_THETA:        14.82 [deg]
  DELTA_TIME:      6.00 [sec]
  TRIGGER_DUR:     2.048 [sec] 
  SOLN_STATUS:     0x403
  RATE_SIGNIF:     12.80 [sigma]
  IMAGE_SIGNIF:    7.13 [sigma]
  LC_URL:          sw00292826000msb.lc
  SUN_POSTN:       187.46d {+12h 29m 50s}   -3.22d {-03d 13' 14"}
  SUN_DIST:         63.48 [deg]   Sun_angle= 2.5 [hr] (West of Sun)
  MOON_POSTN:       73.69d {+04h 54m 45s}  +27.78d {+27d 47' 06"}
  MOON_DIST:       107.23 [deg]
  MOON_ILLUM:      69 [%]
  GAL_COORDS:      282.75, -3.81 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      194.29,-63.31 [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:        This trigger occurred at longitude,latitude = 242.31,-10.43 [deg].  
  COMMENTS:           
  COMMENTS:        This trigger occured while the StarTracker had lost lock, so it is possibly bogus.  
  

  
• GCN Circular #6832
  M. De Pasquale (UCL-MSSL), S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester), S. Campana (INAF-OAB), J. R. Cummings (NASA/UMBC), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC), C. Gronwall (PSU), C. Guidorzi (Univ Bicocca&INAF-OAB), S. T. Holland (CRESST/USRA/GSFC), H. A. Krimm (GSFC/USRA), V. Mangano (INAF-IASFPA), C. B. Markwardt (CRESST/GSFC/UMD), F. E. Marshall (NASA/GSFC), A. Moretti (INAF-OAB), C. Pagani (PSU), K. L. Page (U Leicester), D. M. Palmer (LANL), J. L. Racusin (PSU), G. Sato (GSFC/ISAS), M. Stamatikos (NASA/ORAU), R. L. C. Starling (U Leicester), E. Troja (INAF-IASFPA), T. N. Ukwatta (GSFC/GWU) and L. Vetere (PSU) report on behalf of the Swift Team:
  At 16:31:48 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 071001 (trigger=292826). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 149.766, -59.751 which is

     RA(J2000) = 09h 59m 04s
     Dec(J2000) = -59d 45' 02"
  

  with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows two isolated peaks spanning a duration of about 50 sec. The peak count rate was ~1500 counts/sec (15-350 keV), at ~0 sec after the trigger.
  The XRT began observing the field at 16:33:10 UT, 83 seconds after the BAT trigger. Using prompt downlinked data, we find a bright, variable, uncatalogued X-ray source located at RA, Dec 149.7302, -59.7819 which is

     RA(J2000)  = 09h 58m 55.25s
     Dec(J2000) = -59d 46' 54.8"
  

  with an uncertainty of 6.0 arcsec (radius, 90% containment). This location is 129 arcseconds from the BAT on-board position, within the BAT error circle. The initial flux in the 2.5s image was 1.5e-09 erg/cm2/s (0.2-10 keV).
  The star tracker during the XRT observation has detected and identified three valid stars, however the attitude solution quality is worse than normal. Therefore, there may be some additional systematic error in the quoted positions.
  Burst Advocate for this burst is M. De Pasquale (mdp AT mssl.ucl.ac.uk). 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 NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Mon 01 Oct 07 17:22:12 UT
  NOTICE_TYPE:     Swift-XRT Position UPDATE
  TRIGGER_NUM:     292826,   Seg_Num: 0
  GRB_RA:          149.7301d {+09h 58m 55.2s} (J2000),
                   149.7921d {+09h 59m 10.0s} (current),
                   149.3308d {+09h 57m 19.3s} (1950)
  GRB_DEC:         -59.7819d {-59d 46' 54.8"} (J2000),
                   -59.8192d {-59d 49' 09.0"} (current),
                   -59.5419d {-59d 32' 30.9"} (1950)
  GRB_ERROR:       5.8 [arcsec radius, statistical plus systematic, 90% containment]
  GRB_INTEN:       1.00e-10 [erg/cm2/sec]
  GRB_SIGNIF:      10.00 [sigma]
  IMG_START_DATE:  14374 TJD;   274 DOY;   07/10/01
  IMG_START_TIME:  59631.00 SOD {16:33:51.00} UT,   122.9 [sec] since BAT Trigger Time
  TAM[0-3]:        100.00 100.00 100.00 100.00
  AMPLIFIER:       1
  WAVEFORM:        31
  SUN_POSTN:       187.49d {+12h 29m 57s}   -3.23d {-03d 14' 00"}
  SUN_DIST:         63.52 [deg]   Sun_angle= 2.5 [hr] (West of Sun)
  MOON_POSTN:       74.21d {+04h 56m 50s}  +27.83d {+27d 49' 52"}
  MOON_DIST:       107.03 [deg]
  MOON_ILLUM:      69 [%]
  GAL_COORDS:      282.76, -3.85 [deg] galactic lon,lat of the burst
  ECL_COORDS:      194.32,-63.35 [deg] ecliptic lon,lat of the burst
  COMMENTS:        SWIFT-XRT Coordinates.
  COMMENTS:        This Notice was ground-generated -- not flight-generated.
  COMMENTS:        This is an Update Notice -- the RA,Dec values herein supersede the previous XRT_POS Notice.
  COMMENTS:        TAM values, flux and significance fields are not valid
  COMMENTS:        This position was automatically generated on the ground using
  COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).
  COMMENTS:        See http://www.swift.ac.uk/sper.php for details.
  
  

• GCN Circular #6833
  D. Bersier (Liverpool JMU), C. Guidorzi (U. Bicocca & INAF-OAB), R. Smith (Liverpool JMU) report on behalf of a larger collaboration:
  We observed the field of GRB 071001 (Swift trigger 292826, GCN 6832) with the Faulkes Telescope South in BVRi filters. We do not detect any variable object within the XRT error circle down to mR=19.5 (calibrated with respect to USNO-B).
  We note that a fairly bright object within the XRT error circle may complicate the analysis.
• GCN Circular #6834
  M. Stamatikos (GSFC/ORAU), L. Barbier (GSFC), S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC), M. De Pasquale (UCL-MSSL), T. Sakamoto (GSFC/UMBC), G. Sato (GSFC/ISAS), J. Tueller (GSFC), T. Ukwatta (GWU) (i.e. the Swift-BAT team):
  Using the data set from T-119 to T+183 sec from recent telemetry downlinks, we report further analysis of BAT GRB 071001 (trigger #292826) (De Pasquale, et al., GCN Circ. 6832). The BAT ground-calculated position is RA, Dec = 149.707, -59.763 deg which is

     RA(J2000)  =  09h 58m 49.7s 
     Dec(J2000) = -59d 45' 48" 
  

  with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 85%.
  The mask-weighted light curve shows two main peaks: 1) starting/peaking/ending at ~T-20/0/+30 sec, resp; 2) T+40/+48/+70; and a much weaker (~3 sigma) peak: ~T+70/+90/+100 sec. T90 (15-350 keV) is 58.5 +- 1.0 sec (estimated error including systematics).
  The time-averaged spectrum from T-1.6 to T+64.7 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.62 +- 0.17. The fluence in the 15-150 keV band is 7.7 +- 0.8 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+48.14 sec in the 15-150 keV band is 0.9 +- 0.1 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
• GCN Circular #6835
  K.L. Page, A.P. Beardmore (U. Leicester) and M. De Pasquale (UCL-MSSL) report on behalf of the Swift-XRT team:
  We have analysed the two orbits of Swift-XRT data obtained for GRB 071001 (De Pasquale et al., GCN Circ. 6832), totalling 37 seconds of Windowed Timing (WT) data and 1.3 ks of Photon Counting mode data. Because of a temporary problem with the star trackers, we use only the data when the attitude can be said to be stable to find a refined position of RA, Dec = 149.7336, -59.7818, which is equivalent to:

  RA(J2000):   09 58 56.07
  Dec(J2000): -59 46 54.5
  

  with an estimated uncertainty of 6 arcsec (radius, 90% containment including boresight uncertainty). This is 83 arcsec from the ground-calculated BAT position (Stamatikos et al., GCN Circ. 6834) and 6.2 arcsec from the initial XRT position quoted in GCN Circ. 6832.
  The X-ray light-curve shows an initial steep decay, with alpha = 3.0 +/- 0.2, breaking at about 310 seconds after the trigger to a flatter slope of 0.2 +/- 0.1.
  The WT spectrum (89-120 seconds after the trigger) can be modelled by a power-law of Gamma = 2.2 +0.5/-0.4, absorbed by the Galactic column in this direction of 7.6e21 cm^-2. The 0.3-10 keV observed (unabsorbed) flux during this time is 4.2e-10 (2.0e-9) erg cm^-2 s^-1.
  With only 2 orbits of data, predicting the count rate at 24 hours would not lead to an accurate result. No further Swift observations of this burst are planned.
  This circular is an official product of the Swift-XRT team.
• GCN Report 86.1
  GCN_Report 86.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_86_1.pdf by M. De Pasquale at UCL/MSSL titled: "Swift Observations of 071001"