Gamma-ray Burst 071025

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN/BACODINE POSITION NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Thu 25 Oct 07 04:10:09 UT
  NOTICE_TYPE:     Swift-BAT GRB Position
  TRIGGER_NUM:     295301,   Seg_Num: 0
  GRB_RA:          355.084d {+23h 40m 20s} (J2000),
                   355.182d {+23h 40m 44s} (current),
                   354.459d {+23h 37m 50s} (1950)
  GRB_DEC:         +31.757d {+31d 45' 24"} (J2000),
                   +31.800d {+31d 48' 01"} (current),
                   +31.480d {+31d 28' 46"} (1950)
  GRB_ERROR:       3.00 [arcmin radius, statistical only]
  GRB_INTEN:       0 [cnts]    Image_Peak=2035 [image_cnts]
  TRIGGER_DUR:     64.000 [sec] 
  TRIGGER_INDEX:   20000     E_range: 15-50 keV
  BKG_INTEN:       0 [cnts]
  BKG_TIME:        0.00 SOD {00:00:00.00} UT
  BKG_DUR:         0 [sec]
  GRB_DATE:        14398 TJD;   298 DOY;   07/10/25
  GRB_TIME:        14933.68 SOD {04:08:53.68} UT
  GRB_PHI:         135.85 [deg]
  GRB_THETA:        30.58 [deg]
  SOLN_STATUS:     0x13
  RATE_SIGNIF:     0.00 [sigma]
  IMAGE_SIGNIF:    10.87 [sigma]
  MERIT_PARAMS:     +1  +0  +0  +6  +1  +0  +0  +0 +79  +1 
  SUN_POSTN:       209.22d {+13h 56m 52s}  -11.95d {-11d 56' 52"}
  SUN_DIST:        142.95 [deg]   Sun_angle= -9.7 [hr] (East of Sun)
  MOON_POSTN:       14.00d {+00h 56m 00s}   +9.62d {+09d 37' 26"}
  MOON_DIST:        28.21 [deg]
  MOON_ILLUM:      98 [%]
  GAL_COORDS:      105.71,-28.73 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:        9.55, 30.79 [deg] ecliptic lon,lat of the burst (or transient)
  COMMENTS:        SWIFT-BAT GRB Coordinates.  
  COMMENTS:        This is an image trigger.  (The RATE_SIGNIF & BKG_{INTEN, TIME, DUR} are undefined.)  
  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 = 333.73,18.11 [deg].  
  

• red DSS finding chart ps-file
  
  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Thu 25 Oct 07 04:11:53 UT
  NOTICE_TYPE:     Swift-XRT Image
  TRIGGER_NUM:     295301,   Seg_Num: 0
  GRB_RA:          355.0765d {+23h 40m 18.3s} (J2000),
                   355.1743d {+23h 40m 41.8s} (current),
                   354.4516d {+23h 37m 48.3s} (1950)
  GRB_DEC:         +31.7776d {+31d 46' 39.3"} (J2000),
                   +31.8209d {+31d 49' 15.3"} (current),
                   +31.5004d {+31d 30' 01.2"} (1950)
  GRB_ERROR:       6.8 [arcsec, radius, statistical plus systematic]
  GRB_INTEN:       27 [cnts]
  IMG_START_DATE:  14398 TJD;   298 DOY;   07/10/25
  IMG_START_TIME:  15079.88 SOD {04:11:19.88} UT,   146.2 [sec] since BAT Trigger Time
  CENTROID_X:      305.33,  raw= 305  [pixels]
  CENTROID_Y:      281.71,  raw= 282  [pixels]
  ROLL:            294.49 [deg]
  GAIN:            1
  MODE:            2, Short Image mode
  WAVEFORM:        134
  EXPO_TIME:       0.10 [sec]
  GRB_POS_XRT_Y:   -38.38
  GRB_POS_XRT_Z:   7.14
  IMAGE_URL:       sw00295301000msxps_rw.img
  SUN_POSTN:       209.22d {+13h 56m 52s}  -11.95d {-11d 56' 54"}
  SUN_DIST:        142.94 [deg]   Sun_angle= -9.7 [hr] (East of Sun)
  MOON_POSTN:       14.02d {+00h 56m 04s}   +9.63d {+09d 37' 55"}
  MOON_DIST:        28.23 [deg]
  MOON_ILLUM:      98 [%]
  GAL_COORDS:      105.71,-28.70 [deg] galactic lon,lat of the burst
  ECL_COORDS:        9.55, 30.81 [deg] ecliptic lon,lat of the burst
  COMMENTS:        SWIFT-XRT Image.  
  

  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Thu 25 Oct 07 04:11:56 UT
  NOTICE_TYPE:     Swift-XRT Processed Image
  TRIGGER_NUM:     295301,   Seg_Num: 0
  GRB_RA:          355.0765d {+23h 40m 18.3s} (J2000),
                   355.1743d {+23h 40m 41.8s} (current),
                   354.4516d {+23h 37m 48.3s} (1950)
  GRB_DEC:         +31.7776d {+31d 46' 39.3"} (J2000),
                   +31.8209d {+31d 49' 15.3"} (current),
                   +31.5004d {+31d 30' 01.2"} (1950)
  GRB_ERROR:       6.8 [arcsec, radius, statistical plus systematic]
  GRB_INTEN:       27 [cnts]
  IMG_START_DATE:  14398 TJD;   298 DOY;   07/10/25
  IMG_START_TIME:  15079.88 SOD {04:11:19.88} UT,   146.2 [sec] since BAT Trigger Time
  CENTROID_X:      305.33,  raw= 305  [pixels]
  CENTROID_Y:      281.71,  raw= 282  [pixels]
  ROLL:            294.49 [deg]
  GAIN:            1
  MODE:            2, Short Image mode
  WAVEFORM:        134
  EXPO_TIME:       0.10 [sec]
  GRB_POS_XRT_Y:   -38.38
  GRB_POS_XRT_Z:   7.14
  IMAGE_URL:       sw00295301000msxps_rw.img
  SUN_POSTN:       209.22d {+13h 56m 52s}  -11.95d {-11d 56' 54"}
  SUN_DIST:        142.94 [deg]   Sun_angle= -9.7 [hr] (East of Sun)
  MOON_POSTN:       14.02d {+00h 56m 04s}   +9.63d {+09d 37' 56"}
  MOON_DIST:        28.23 [deg]
  MOON_ILLUM:      98 [%]
  GAL_COORDS:      105.71,-28.70 [deg] galactic lon,lat of the burst
  ECL_COORDS:        9.55, 30.81 [deg] ecliptic lon,lat of the burst
  COMMENTS:        SWIFT-XRT Processed Image.  
  

  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Thu 25 Oct 07 04:11:52 UT
  NOTICE_TYPE:     Swift-XRT Position
  TRIGGER_NUM:     295301,   Seg_Num: 0
  GRB_RA:          355.0765d {+23h 40m 18.3s} (J2000),
                   355.1743d {+23h 40m 41.8s} (current),
                   354.4516d {+23h 37m 48.3s} (1950)
  GRB_DEC:         +31.7776d {+31d 46' 39.3"} (J2000),
                   +31.8209d {+31d 49' 15.3"} (current),
                   +31.5004d {+31d 30' 01.2"} (1950)
  GRB_ERROR:       6.8 [arcsec radius, statistical plus systematic, 90% containment]
  GRB_INTEN:       9.11e-09 [erg/cm2/sec]
  GRB_SIGNIF:      5.19 [sigma]
  IMG_START_DATE:  14398 TJD;   298 DOY;   07/10/25
  IMG_START_TIME:  15079.88 SOD {04:11:19.88} UT,   146.2 [sec] since BAT Trigger Time
  TAM[0-3]:        327.64 237.27 261.29 243.55
  AMPLIFIER:       2
  WAVEFORM:        134
  SUN_POSTN:       209.22d {+13h 56m 52s}  -11.95d {-11d 56' 54"}
  SUN_DIST:        142.94 [deg]   Sun_angle= -9.7 [hr] (East of Sun)
  MOON_POSTN:       14.02d {+00h 56m 04s}   +9.63d {+09d 37' 55"}
  MOON_DIST:        28.23 [deg]
  MOON_ILLUM:      98 [%]
  GAL_COORDS:      105.71,-28.70 [deg] galactic lon,lat of the burst
  ECL_COORDS:        9.55, 30.81 [deg] ecliptic lon,lat of the burst
  COMMENTS:        SWIFT-XRT Coordinates.  
  

• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Thu 25 Oct 07 04:13:06 UT
  NOTICE_TYPE:     Swift-BAT GRB Lightcurve
  TRIGGER_NUM:     295301,   Seg_Num: 0
  GRB_RA:          355.084d {+23h 40m 20s} (J2000),
                   355.182d {+23h 40m 44s} (current),
                   354.459d {+23h 37m 50s} (1950)
  GRB_DEC:         +31.757d {+31d 45' 24"} (J2000),
                   +31.800d {+31d 48' 01"} (current),
                   +31.480d {+31d 28' 46"} (1950)
  GRB_DATE:        14398 TJD;   298 DOY;   07/10/25
  GRB_TIME:        14933.68 SOD {04:08:53.68} UT
  TRIGGER_INDEX:   20000
  GRB_PHI:         135.85 [deg]
  GRB_THETA:        30.58 [deg]
  DELTA_TIME:      0.00 [sec]
  TRIGGER_DUR:     64.000 [sec] 
  SOLN_STATUS:     0x13
  RATE_SIGNIF:     0.00 [sigma]
  IMAGE_SIGNIF:    10.87 [sigma]
  LC_URL:          sw00295301000msb.lc
  SUN_POSTN:       209.22d {+13h 56m 53s}  -11.95d {-11d 56' 55"}
  SUN_DIST:        142.95 [deg]   Sun_angle= -9.7 [hr] (East of Sun)
  MOON_POSTN:       14.03d {+00h 56m 07s}   +9.64d {+09d 38' 16"}
  MOON_DIST:        28.21 [deg]
  MOON_ILLUM:      98 [%]
  GAL_COORDS:      105.71,-28.73 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:        9.55, 30.79 [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 an image 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 = 333.73,18.11 [deg].  
  

  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Thu 25 Oct 07 04:14:12 UT
  NOTICE_TYPE:     Swift-UVOT Source List
  TRIGGER_NUM:     295301,   Seg_Num: 0
  POINT_RA:        355.068d {+23h 40m 16s} (J2000)
  POINT_DEC:       +31.767d {+31d 46' 02"} (J2000)
  POINT_ROLL:      294.486d
  IMG_START_DATE:  14398 TJD;   298 DOY;   07/10/25
  IMG_START_TIME:  15088.58 SOD {04:11:28.58} UT,   154.9 [sec] since BAT Trigger Time
  FILTER:          10, White
  BKG_MEAN:        1.298
  N_STARS:         42
  X_OFFSET:        352 [pixels]
  Y_OFFSET:        576 [pixels]
  X_MAX:           1311 [pixels]
  Y_MAX:           1535 [pixels]
  DET_THRESH:      10
  PHOTO_THRESH:    5
  SL_URL:          sw00295301000msufc0154.fits
  SUN_POSTN:       209.22d {+13h 56m 53s}  -11.95d {-11d 56' 56"}
  SUN_DIST:        142.93 [deg]   Sun_angle= -9.7 [hr] (East of Sun)
  MOON_POSTN:       14.04d {+00h 56m 09s}   +9.64d {+09d 38' 34"}
  MOON_DIST:        28.23 [deg]
  MOON_ILLUM:      98 [%]
  GAL_COORDS:      105.70,-28.71 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:        9.54, 30.80 [deg] ecliptic lon,lat of the pointing direction
  COMMENTS:        SWIFT-UVOT Source List.  
  

• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Thu 25 Oct 07 04:15:28 UT
  NOTICE_TYPE:     Swift-UVOT Image
  TRIGGER_NUM:     295301,   Seg_Num: 0
  POINT_RA:        355.068d {+23h 40m 16s} (J2000)
  POINT_DEC:       +31.767d {+31d 46' 02"} (J2000)
  ROLL:            294.486d
  IMG_START_DATE:  14398 TJD;   298 DOY;   07/10/25
  IMG_START_TIME:  15088.58 SOD {04:11:28.58} UT,   154.9 [sec] since BAT Trigger Time
  FILTER:          10, White
  EXPOSURE_ID:     214978290
  X_OFFSET:        821 [pixels]
  Y_OFFSET:        949 [pixels]
  WIDTH:           160 [pixels]
  HEIGHT:          160 [pixels]
  X_GRB_POS:       981
  Y_GRB_POS:       1109
  BINNING_INDEX:   1
  IM_URL:          sw00295301000msuni0154.fits
  SUN_POSTN:       209.22d {+13h 56m 53s}  -11.95d {-11d 56' 57"}
  SUN_DIST:        142.93 [deg]   Sun_angle= -9.7 [hr] (East of Sun)
  MOON_POSTN:       14.05d {+00h 56m 12s}   +9.65d {+09d 38' 55"}
  MOON_DIST:        28.23 [deg]
  MOON_ILLUM:      98 [%]
  GAL_COORDS:      105.70,-28.71 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:        9.54, 30.80 [deg] ecliptic lon,lat of the pointing direction
  COMMENTS:        SWIFT-UVOT Image.  
  COMMENTS:        The GRB Position came from the XRT Position Command.  
  COMMENTS:        The image has 2x2 binning (compression).  
  

  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Thu 25 Oct 07 04:16:01 UT
  NOTICE_TYPE:     Swift-UVOT Processed Image
  TRIGGER_NUM:     295301,   Seg_Num: 0
  POINT_RA:        355.068d {+23h 40m 16s} (J2000)
  POINT_DEC:       +31.767d {+31d 46' 02"} (J2000)
  ROLL:            294.486d
  IMG_START_DATE:  14398 TJD;   298 DOY;   07/10/25
  IMG_START_TIME:  15088.58 SOD {04:11:28.58} UT,   154.9 [sec] since BAT Trigger Time
  FILTER:          10, White
  EXPOSURE_ID:     214978290
  X_OFFSET:        821 [pixels]
  Y_OFFSET:        949 [pixels]
  WIDTH:           160 [pixels]
  HEIGHT:          160 [pixels]
  X_GRB_POS:       981
  Y_GRB_POS:       1109
  BINNING_INDEX:   1
  IM_URL:          sw00295301000msuni0154.fits
  SUN_POSTN:       209.22d {+13h 56m 53s}  -11.95d {-11d 56' 57"}
  SUN_DIST:        142.93 [deg]   Sun_angle= -9.7 [hr] (East of Sun)
  MOON_POSTN:       14.06d {+00h 56m 14s}   +9.65d {+09d 39' 04"}
  MOON_DIST:        28.23 [deg]
  MOON_ILLUM:      98 [%]
  GAL_COORDS:      105.70,-28.71 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:        9.54, 30.80 [deg] ecliptic lon,lat of the pointing direction
  COMMENTS:        SWIFT-UVOT Processed Image.  
  COMMENTS:        The GRB Position came from the XRT Position Command.  
  COMMENTS:        The image has 2x2 binning (compression).  
  COMMENTS:        If you have elected to receive attachments:  
  COMMENTS:        The uvot_sources_image.fits.gz file does not exist; skipping the attachment.  
  

  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Thu 25 Oct 07 04:17:17 UT
  NOTICE_TYPE:     Swift-UVOT Source List
  TRIGGER_NUM:     295301,   Seg_Num: 0
  POINT_RA:        355.069d {+23h 40m 17s} (J2000)
  POINT_DEC:       +31.769d {+31d 46' 07"} (J2000)
  POINT_ROLL:      294.488d
  IMG_START_DATE:  14398 TJD;   298 DOY;   07/10/25
  IMG_START_TIME:  15194.62 SOD {04:13:14.62} UT,   260.9 [sec] since BAT Trigger Time
  FILTER:          3, V
  BKG_MEAN:        0.447
  N_STARS:         33
  X_OFFSET:        501 [pixels]
  Y_OFFSET:        629 [pixels]
  X_MAX:           1460 [pixels]
  Y_MAX:           1588 [pixels]
  DET_THRESH:      6
  PHOTO_THRESH:    3
  SL_URL:          sw00295301000msufc0260.fits
  SUN_POSTN:       209.22d {+13h 56m 53s}  -11.95d {-11d 56' 59"}
  SUN_DIST:        142.93 [deg]   Sun_angle= -9.7 [hr] (East of Sun)
  MOON_POSTN:       14.07d {+00h 56m 16s}   +9.66d {+09d 39' 26"}
  MOON_DIST:        28.24 [deg]
  MOON_ILLUM:      98 [%]
  GAL_COORDS:      105.70,-28.71 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:        9.54, 30.80 [deg] ecliptic lon,lat of the pointing direction
  COMMENTS:        SWIFT-UVOT Source List.  
  

• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Thu 25 Oct 07 04:18:06 UT
  NOTICE_TYPE:     Swift-UVOT Image
  TRIGGER_NUM:     295301,   Seg_Num: 0
  POINT_RA:        355.069d {+23h 40m 17s} (J2000)
  POINT_DEC:       +31.769d {+31d 46' 07"} (J2000)
  ROLL:            294.488d
  IMG_START_DATE:  14398 TJD;   298 DOY;   07/10/25
  IMG_START_TIME:  15194.62 SOD {04:13:14.62} UT,   260.9 [sec] since BAT Trigger Time
  FILTER:          3, V
  EXPOSURE_ID:     214978396
  X_OFFSET:        821 [pixels]
  Y_OFFSET:        949 [pixels]
  WIDTH:           160 [pixels]
  HEIGHT:          160 [pixels]
  X_GRB_POS:       981
  Y_GRB_POS:       1109
  BINNING_INDEX:   1
  IM_URL:          sw00295301000msuni0260.fits
  SUN_POSTN:       209.22d {+13h 56m 53s}  -11.95d {-11d 57' 00"}
  SUN_DIST:        142.93 [deg]   Sun_angle= -9.7 [hr] (East of Sun)
  MOON_POSTN:       14.08d {+00h 56m 18s}   +9.66d {+09d 39' 39"}
  MOON_DIST:        28.24 [deg]
  MOON_ILLUM:      98 [%]
  GAL_COORDS:      105.70,-28.71 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:        9.54, 30.80 [deg] ecliptic lon,lat of the pointing direction
  COMMENTS:        SWIFT-UVOT Image.  
  COMMENTS:        The GRB Position came from the XRT Position Command.  
  COMMENTS:        The image has 2x2 binning (compression).  
  

  
• GCN Circular #6986
  C. Pagani (PSU), W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU), J. R. Cummings (NASA/UMBC), N. Gehrels (NASA/GSFC), C. Gronwall (PSU), C. B. Markwardt (CRESST/GSFC/UMD), F. E. Marshall (NASA/GSFC), J. L. Racusin (PSU), T. N. Ukwatta (GSFC/GWU) and L. Vetere (PSU) report on behalf of the Swift Team:
  At 04:08:54 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 071025 (trigger=295301). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 355.084, +31.757 which is

     RA(J2000)  =  23h 40m 20s
     Dec(J2000) = +31d 45' 24"
  

  with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). Although this is a 64 sec image trigger, the light curve appears to have a single broad peak with duration about 120 sec near time T+100, with peak count rate 2000 ct/s.
  The XRT began observing the field at 04:11:19 UT, 146 seconds after the BAT trigger. XRT found a bright, fading, uncatalogued X-ray source located at RA, Dec 355.0765, +31.7776 which is

     RA(J2000)  =  23h 40m 18.3s
     Dec(J2000) =  31d 46' 39.3"
  

  with an uncertainty of 6.8 arcseconds (radius, 90% containment). This location is 78 arcseconds from the BAT on-board position, within the BAT error circle. The initial flux in the 0.1s image was 9.1e-09 erg/cm2/s (0.2-10 keV).
  UVOT took a finding chart exposure of 100 seconds with the White (160-650 nm) filter starting 155 seconds after the BAT trigger. No afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the XRT error circle. The typical 3-sigma upper limit has been about 18.5 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.08.
  Burst Advocate for this burst is C. Pagani (pagani AT astro.psu.edu). 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 #6987
  E.S. Rykoff (UCSB), F. Yuan (U Mich), B. E. Schaefer (Louisiana State), H. Swan (U Mich), R. Quimby (Caltech), report on behalf of the ROTSE collaboration:
  ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 071025 (Swift trigger 295301, GCN 6986). The first image was at 04:10:14.0 UT, 80.3 s after the burst (6.0 s after the GCN notice time). The unfiltered images are calibrated relative to USNO A2.0. We detect a 19.2 magnitude, fading source with coordinates:
  23:40:17.19 +31:46:42.64 (J2000), with positional uncertainty of 1" or better

  start UT    	mag     mlim(of image)
  ----------------------------------
  04:16:27.1     19.2     18.6
  

  This source is not visible in DSS (second epoch), 2MASS or the MPChecker database.
  A jpeg image is available at http://www.rotse.net/images/gsb295301_3b021-030_key.jpg
  Continuing observations are in progress.
  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Thu 25 Oct 07 04:18:49 UT
  NOTICE_TYPE:     Swift-UVOT Processed Image
  TRIGGER_NUM:     295301,   Seg_Num: 0
  POINT_RA:        355.069d {+23h 40m 17s} (J2000)
  POINT_DEC:       +31.769d {+31d 46' 07"} (J2000)
  ROLL:            294.488d
  IMG_START_DATE:  14398 TJD;   298 DOY;   07/10/25
  IMG_START_TIME:  15194.62 SOD {04:13:14.62} UT,   260.9 [sec] since BAT Trigger Time
  FILTER:          3, V
  EXPOSURE_ID:     214978396
  X_OFFSET:        821 [pixels]
  Y_OFFSET:        949 [pixels]
  WIDTH:           160 [pixels]
  HEIGHT:          160 [pixels]
  X_GRB_POS:       981
  Y_GRB_POS:       1109
  BINNING_INDEX:   1
  IM_URL:          sw00295301000msuni0260.fits
  SUN_POSTN:       209.22d {+13h 56m 53s}  -11.95d {-11d 57' 00"}
  SUN_DIST:        142.93 [deg]   Sun_angle= -9.7 [hr] (East of Sun)
  MOON_POSTN:       14.08d {+00h 56m 20s}   +9.66d {+09d 39' 51"}
  MOON_DIST:        28.24 [deg]
  MOON_ILLUM:      98 [%]
  GAL_COORDS:      105.70,-28.71 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:        9.54, 30.80 [deg] ecliptic lon,lat of the pointing direction
  COMMENTS:        SWIFT-UVOT Processed Image.  
  COMMENTS:        The GRB Position came from the XRT Position Command.  
  COMMENTS:        The image has 2x2 binning (compression).  
  COMMENTS:        If you have elected to receive attachments:  
  COMMENTS:        The uvot_sources_image.fits.gz file does not exist; skipping the attachment.  
  

  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Thu 25 Oct 07 04:14:42 UT
  NOTICE_TYPE:     Swift-UVOT Processed Source List
  TRIGGER_NUM:     295301,   Seg_Num: 0
  POINT_RA:        355.068d {+23h 40m 16s} (J2000)
  POINT_DEC:       +31.767d {+31d 46' 02"} (J2000)
  POINT_ROLL:      294.486d
  IMG_START_DATE:  14398 TJD;   298 DOY;   07/10/25
  IMG_START_TIME:  15088.58 SOD {04:11:28.58} UT,   154.9 [sec] since BAT Trigger Time
  FILTER:          10, White
  BKG_MEAN:        1.298
  N_STARS:         42
  X_OFFSET:        352 [pixels]
  Y_OFFSET:        576 [pixels]
  X_MAX:           1311 [pixels]
  Y_MAX:           1535 [pixels]
  DET_THRESH:      10
  PHOTO_THRESH:    5
  SL_URL:          sw00295301000msufc0154.fits
  SUN_POSTN:       209.22d {+13h 56m 53s}  -11.95d {-11d 56' 56"}
  SUN_DIST:        142.93 [deg]   Sun_angle= -9.7 [hr] (East of Sun)
  MOON_POSTN:       14.04d {+00h 56m 11s}   +9.65d {+09d 38' 42"}
  MOON_DIST:        28.23 [deg]
  MOON_ILLUM:      98 [%]
  GAL_COORDS:      105.70,-28.71 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:        9.54, 30.80 [deg] ecliptic lon,lat of the pointing direction
  COMMENTS:        SWIFT-UVOT Processed Source List.  
  COMMENTS:        All 4 attachments are included.  
  

  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Thu 25 Oct 07 04:18:23 UT
  NOTICE_TYPE:     Swift-UVOT Processed Source List
  TRIGGER_NUM:     295301,   Seg_Num: 0
  POINT_RA:        355.069d {+23h 40m 17s} (J2000)
  POINT_DEC:       +31.769d {+31d 46' 07"} (J2000)
  POINT_ROLL:      294.488d
  IMG_START_DATE:  14398 TJD;   298 DOY;   07/10/25
  IMG_START_TIME:  15194.62 SOD {04:13:14.62} UT,   260.9 [sec] since BAT Trigger Time
  FILTER:          3, V
  BKG_MEAN:        0.447
  N_STARS:         33
  X_OFFSET:        501 [pixels]
  Y_OFFSET:        629 [pixels]
  X_MAX:           1460 [pixels]
  Y_MAX:           1588 [pixels]
  DET_THRESH:      6
  PHOTO_THRESH:    3
  SL_URL:          sw00295301000msufc0260.fits
  SUN_POSTN:       209.22d {+13h 56m 53s}  -11.95d {-11d 57' 00"}
  SUN_DIST:        142.93 [deg]   Sun_angle= -9.7 [hr] (East of Sun)
  MOON_POSTN:       14.08d {+00h 56m 19s}   +9.66d {+09d 39' 44"}
  MOON_DIST:        28.24 [deg]
  MOON_ILLUM:      98 [%]
  GAL_COORDS:      105.70,-28.71 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:        9.54, 30.80 [deg] ecliptic lon,lat of the pointing direction
  COMMENTS:        SWIFT-UVOT Processed Source List.  
  COMMENTS:        All 4 attachments are included.  
  

  
• GCN Circular #6988
  S. Covino, S. Piranomonte, D. Fugazza, L.A. Antonelli, L. Calzoletti, S. Campana, G. Chincarini, M.L. Conciatore, S. Cutini, P. D'Avanzo, V. D'Elia, F. Dalessio, F. Fiore, P. Goldoni, D. Guetta, C. Guidorzi, G.L. Israel, N. Masetti, A. Melandri, E. Meurs, L. Nicastro, E. Palazzi, E. Pian, S. Piranomonte, L. Stella, G. Stratta, G. Tagliaferri, G. Tosti, V. Testa, S.D. Vergani, F. Vitali report on behalf of the REM team:
  The NIR afterglow is detected by the REM telescope at coordinates:

  RA = 23:40:17.1
  DEC = 31:46:43.6
  

  with H~13.8 at 4:18:12 UT.
  The source is NOT in the XRT error circle, although rather close to it. The source is bright, and not present in the 2MASS or USNO catalogues. The source is compatible with that reported by Rykoff et al. (GCN 6987).
  Further observations are in progress.
• GCN Circular #6989
  J. S. Bloom (UC Berkeley) reports on behalf of a larger collaboration:
  "Under autonomous operations, we started observing the position of GRB 071025a (Pagani et al. GCN 6986) with PAIRITEL at 04:11:08 UT (about 58s after receiving the trigger). In a mosaic of data obtained between 2007-10-25 04:12:28 to 2007-10-25 04:21:23 UT, we confirm the existence of a bright new source (Rykoff et al. GCN 6987; Covino et al. GCN 6988) at position:
  23:40:17.078 +31:46:42.87 (J2000)
  with an uncertainty of 250 mas in both axes (relative to 2MASS). A preliminary magnitude is J = 14.948 +/- 0.022. More observations and analysis are ongoing."
  A finder of the field may be obtained at: http://lyra.berkeley.edu/~jbloom/grb071025a.ps.gz
  The message may be cited.
• GCN Circular #6990
  C. Pagani (PSU) reports on behalf of the Swift-XRT Team:
  The XRT on-board centroid position of the afterglow of GRB 071025 reported in GCN 6986 was strongly affected by a hot column.
  A refined position from the first 0.1 second image is RA, Dec=355.0737, 31.7782 which is

  RA(J2000)  =23h 40m 17.7s
  Dec(J2000) =+31d 46' 41.4"
  

  with an uncertainty of 8 arcseconds (radius, 90% containment).
  This is 9 arcseconds from the initial XRT position, and 6.5 arcseconds from the optical position reported in GCN 6897.
  This circular is an official product of the Swift-XRT team.
• GCN Circular #6991
  M. Im, I. Lee (Seoul National University), and Y. Urata (Saitama University) on behalf of the EAFON team:
  Using the Mt. Lemmon (Arizona, US) 1.0m telescope operated by the Korea Astronomy Space Science Institute, we observed GRB071025, beginning at 04:35 UT on Oct 25. We have a clear detection of the afterglow in 300 secs frame taken in I-band (GCN6987, Rykoff et al.), but no detection at all in B, V, R-band with the same exposure time. The non-detection R-band suggests that the GRB is likely a R-band dropout at z ~ 6.
  This message may be cited.
  We acknowldege the help of the LOAO operators, J.H. Yoon, for this observation.
• GCN Circular #6992
  E.S. Rykoff (UCSB), F. Yuan (U Mich), B. E. Schaefer (Louisiana State), H. Swan (U Mich), R. Quimby (Caltech), report on behalf of the ROTSE collaboration:
  ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 071025 (Swift trigger 295301, GCN 6986, Pagani, et al.) and detected an optical counterpart as reported in GCN 6987 (Rykoff, et al.). We have improved the photometry and recalibrated the images relative to USNO-B1.0 R-band, which is significantly offset from the magnitudes in USNO-A2.0 R-band.
  From our initial observations at T+80.3s we see the counterpart rise to a peak of 17.3+/-0.2 at T+332s (midtime for a 40s coadd), and then fade slowly over the next 1500 s. At T+595s (midtime for a 280s coadd) the magnitude is 17.6+/-0.1. This integration is nearly simultaneous with the NIR detections of H~13.8 (Covino, et al., GCN 6988) and J=14.95 (Bloom, et al., GCN 6989).
  Although the ROTSE-III images are calibrated relative to R-band, the unfiltered CCD has significant sensitivity redward of R. Our observations are thus consistent with a possible R-band dropout (Im, et al., GCN 6991) and UVOT non-detection (Pangani, et al., GCN 6986).
  We can assume that the intrinsic GRB spectrum as an R-J color of ~1, and the reddening is entirely caused by the intergalactic medium (IGM). We then use the ROTSE-III magnitude and the integrated ROTSE-III response curve convolved with the IGM absorption model of Meiksin (2005) to estimate an upper limit on the burst redshift of z~5.3 (for more details see Ruiz-Velasco, et al, 2007). We note that at this redshift the R-band offset would be ~1.2 mag, which may be consistent with the limits of Im, et al. However, if the reddening is not caused by absorption in the IGM then the burst redshift may be lower.
• GCN Circular #6994
  M. Im, I. Lee (Seoul National University), and Y. Urata (Saitama University) on behalf of the EAFON team:
  We coninue examination of the data obtained with the Mt. Lemmon (Arizona, US) 1.0m telescope. The afterglow appears to be decaying rapidly after ~2400 secs of the burst. Re-examination of R-band images show a faint smudge which could be due to the afterglow. The detection is consistent with GCN report 071025 (Rykoff et al.), and we set the limit of R -I > ~1.7 mag from our R-band observation. Note that our R-band filter has a long tail toward red wavelenth. Below are rough estimates of I-band magnitudes based on USNO-B stars (error ~ 0.15mag).

      Star time (UT)    Exp Time      I mag
  --------------------------------------
       04:38:08           300s      16.8
       05:08:42           300s      17.2
       05:30:48           300s      18.1
  

  Further examination of the BVRI data is ongoing to check whether this is a red GRB or high-z GRB.
  This message may be cited.
  We acknowldege the help of the LOAO operators, J.H. Yoon, for this observation.
• GCN Circular #6995
  G. G. Williams (MMTO) and P. A. Milne (Steward Observatory), on behalf of the Super-LOTIS Collaboration, report:
  The robotic 0.6-m Super-LOTIS telescope began observing the error box of GRB 071025 (Swift Trigger 295301, Pagani et al. GCN 6986) at 04:10:29.3 UT, 95 seconds after the trigger. Our initial observations include 5 x 10s exposures, 5 x 20s exposures, and 30 x 60s exposures, all in the R-band.
  We detect the afterglow reported by Rykoff et al. (GCN 6987, confirmed by Covino et al. GCN 6988) in the sum of our first ten 60s exposures centered on 04:19:39 UT. We do not detect the afterglow in our single 10s or 20s exposures. Using USNO-B1.0 stars we estimate the following R-band magnitude and upper limits for the OT:

  t_start (UT)     t_mid (UT)     exp t (s)     t_start-t_0 (s)     R Mag
  --------------------------------------------------------------------------------------
  04:10:29.3     04:10:34.3      10               95.3                R > 17.3
  
  04:13:42.1     04:13:52.1      20              288.1               R > 17.8
  
  04:14:08.8     04:19:39.0      600             314.8               R =17.97 +/- 0.17
  

  Our upper limit of R > 17.8 was measured near the time of the unfiltered m=17.3 peak reported by Rykoff et al. (GCN 6992). Additional observations and analysis are ongoing.
• GCN Circular #6996
  S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), C. Pagani (PSU), D. Palmer (LANL), A. Parsons (GSFC), 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+422 sec from the recent telemetry downlink, we report further analysis of BAT GRB 071025 (trigger #295301) (Pagani, et al., GCN Circ. 6986). The BAT ground-calculated position is RA, Dec = 355.065, 31.784 deg, which is

     RA(J2000)  = 23h 40m 15.6s 
     Dec(J2000) = 31d 47' 3" 
  

  with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 48%.
  The mask-weighted light curve shows a broad peak composed of several overlapping subpeaks. It starts at ~T+0 sec, peaks around T+90 sec, and slowly decays out to at least T+422 sec. Because of an observing constraint, the s/c had to slew off the burst location, and so we do not have any information on the continuation of the emission beyond the T+422 sec limit. T90 (15-350 keV) is at least 109 +- 2 sec (estimated error including systematics).
  The time-averaged spectrum from T+38.5 to T+193.8 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.79 +- 0.05. The fluence in the 15-150 keV band is 6.5 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+80.17 sec in the 15-150 keV band is 1.6 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
• GCN Circular #6998
  C. Pagani, D. N. Burrows, J. Racusin (PSU), P. Evans (U Leicester) report on behalf of the Swift-XRT Team:
  We have analysed the first three orbits of Swift-XRT data obtained for GRB 071025 (Pagani et al. GCN Circ. 6986), totalling 250 s of Windowed Timing (WT) data and 2.7 ks of Photon Counting (PC) data.
  Using 1189 seconds of overlapping XRT Photon Counting mode and UVOT V-band data, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 355.07142, 31.77857 which is equivalent to:

  RA (J2000):  23 40 17.14
  Dec (J2000): +31 46 42.9
  

  with an uncertainty of 1.7 arcsec (radius, 90% confidence). This is 7.1 arcsec from the refined XRT position (GCN Circ. 6990) and 0.7 arcsec from the optical afterglow found by ROTSE-III at McDonald Observatory (Rykoff et al., GCN Circ. 6987).
  The bright X-ray light-curve can be fitted by a broken power-law, with an initial steep decay index of 2.8 +/- 0.3 followed by a flatter decay index of 1.5 +/- 0.1 after a break at 260 +/- 20 seconds.
  The WT data (150-400 seconds) can be modelled as an absorbed power-law, with Gamma = 1.40 +/- 0.05 and a total absorbing column of NH = (0.9 +/- 0.1)e21 cm^-2, in excess of the Galactic value of 5.1e20 cm^-2. The 0.3-10 keV observed (unabsorbed) flux during this time is 2.0e-09(2.2e-09) erg cm^-2 s^-1.
  Assuming the source continues to decay with the same decay index of 1.5, we predict an XRT count rate of 7E-3 counts/s at T+24 hours, which corresponds to an observed flux of 4E-13 ergs cm^-2 s^-1.
  This circular is an official product of the Swift-XRT team.
• GCN Circular #6999
  L.P. Xin, M. Zhai, Y.L. Qiu, J.Y. Wei, J.Y. Hu, J.S. Deng, J. Wang , Y. Urata and W.K. Zheng on behalf of EAFON report:
  We have observed the field of GRB071025(C. Pagani , GCN 6986) with TNT 0.8m telescope at Xinglong observatory, started from 10:27:28.296 UT, about 6.3 hours after the burst. The wheter was not good. A series of I-band images were obtained, and no new source was found in our 18*240s combined image within the error region of the XRT(C. Pagani, GCN6986 GCN6990) and the locations reported by E.S. Rykoff(GCN 6987); S. Covino (GCN 6988); J. S. Bloom (GCN 6989;).
  the 3 sigma limit of our combined image derived from USNO-B1.0 Imag was I =18.2 mag at the mean time of 7.1 hours after the burst.
  This message may be cited.
• GCN Circular #7000
  N.P.M. Kuin (MSSL/UCL) and C. Pagani (PSU) report on behalf of the Swift UVOT team:
  The Swift/UVOT observed the field of GRB 071025 (found with Swift BAT, as reported in GCN 6986 of Pagani et al.) beginning 2007-10-25 04:11:11 UT, 137 seconds after the burst trigger time. After a 10 s settling image in V, a 98 s finding chart exposure in the white filter was taken, followed by observations in all filters.
  No new source was found in any of the UVOT observations inside the reported position of the Swift XRT error circle (Pagani et al, GCN 6990, 6998) or the position of the detection of a transient source in the red bands of which the most accurate was the PARITEL observation in the J band (J. Bloom, GCN 6989), consistent with the refined XRT position. We report upper limits at position RA=23:40:17.078, DEC=+31:46:42.87 (J2000).
  The 3-sigma upper limits for detecting a source at the reported position in the co-added frames as determined are:

  Filter   Tstart   Tstop    Exp     Magnitude
              (s)     (s)     (s)    (3-sigma UL)
  White       155   16016    1377     22.82
  v           137   17760    1319     21.22
  b          3968   11968    1194     22.14
  u          3760   23536    2085     22.13
  uvw1       3552   22704    2164     22.05
  uvm2       4784   21808    1082     21.43
  uvw2       4368   16928    1279     21.89
  

  The values quoted above are not corrected for the expected Galactic extinction corresponding to a reddening of E_{B-V} = 0.074 mag in the direction of the burst (Schlegel et al. 1998).
• GCN Circular #7001
  P. Nugent (LBL), N. Butler, J.S. Bloom, and D. Perley (UC Berkley) report:
  We have created a stacked image through the co-addition of 12 unfiltered images taken by the NEAT collaboration and 45 images in the RG610 filter taken by the Palomar-Quest Consortium at the Palomar Oschin Schmidt telescope (obtained from 2001-2007), of 071025 (Pagani et al.; GCN #6986). The stacked image is significantly deeper than the DSS (3 sigma limit of R~22.8 mag).
  There is no source at the position of the counterpart (Rykoff et al. GCN #6987, Covino et al. GCN #6988, Bloom et al. GCN #6989). The image is available at http://www.lbl.gov/~nugent/deepsky.html
  This message may be cited.
• GCN Circular #7002
  J. S. Bloom, N. R. Butler, D. A. Perley, D. L. Starr, R. Foley (UC Berkeley) report:
  "We obtained simultaneous J, H, and Ks band images with fine time sampling (7.8s cadence) of the afterglow (Rykoff et al. 6987; Covino et al. 6988) of GRB 070125A (Pagani et al. 6986) with PAIRITEL (*) beginning ~200s after the BAT trigger. The beginning of the observations coincides with the fading tale of the prompt emission. The IR light curve initially rises, then exhibits two prominent peaks (at T+~500s and T+~1500s) before fading as a powerlaw t^{-1.5+/-0.1}, after t ~ 2000s. A refined data reduction and a search for potential color variations are in progress."
  This message may be cited.
  (*) http://pairitel.org

  *****************************************************
  Joshua Bloom
  Assistant Professor, UC Berkeley
  601 Campbell Hall, Berkeley, CA 94720
  (510) 643-3839 [Office]  447 Campbell
  (510) 643-4621 [Lab]      260 Evans
  http://astro.berkeley.edu/~jbloom 
  *****************************************************
  

• GCN Circular #7003
  L. Jiang, F. Bian, X. Fan (Steward Observatory, University of Arizona) reports:
  Using the Simultaneous Quad Infrared Imaging Device (SQIID) on the Kitt Peak Mayall 4-meter Telescope, we observed GRB 071025 in J, H, K bands simultaneously, beginnig at UT 2007-10-25-05:56:59. With total exposure time of 240 sec in all three bands, we clearly detected the afterglow. Calibrated using local 2MASS sources, the object is at

   J=17.34 +/- 0.05
   H=16.37 +/- 0.05
   K=15.45 +/- 0.05
  

  The photometric errors are dominated by the zeropoint uncertainties from our calibration procedure. The photon noise on the measuremens is <0.01.
  The message may be cited.

  Xiaohui Fan
  Steward Observatory
  The University of Arizona
  933 N. Cherry Ave.
  Tucson, AZ 85721-0065
  Email: fan@as.arizona.edu
  Tel: (520) 626-7558
  Fax: (520) 621-1532
  

  URL: http://sancerre.as.arizona.edu/~fan
• GCN Circular #7004
  Pablo Saz Parkinson (UC Santa Cruz) on behalf of the Milagro collaboration reports:
  We have searched Milagro data for emission at GeV/TeV energies from GRB 071025 detected by Swift (GCN Circ 6986, C. Pagani et al.), during the main period of emission lasting 422s (GCN Circ 6996, S. D. Barthelmy et al.). No evidence for prompt GeV/TeV emission was found. TeV photons are attenuated by pair production with infrared photons in intergalactic space. We calculate uppers limits using the extragalactic infrared background light (EBL) absorption model of Primack et al. 2005 (AIP Conf. Proc. 745, p. 23).
  A preliminary analysis, assuming a differential photon spectral index of -2.4, gives upper limits on E^2dN/dE at 99% confidence of:
  E^2 dN/dE at 200 GeV < 1.4 * 10^(-6) erg cm^(-2) (Assuming z=0)
  and
  E^2 dN/dE at 200 GeV < 2.3 * 10^(-5) erg cm^(-2) (Assuming z=0.5) E^2 dN/dE at 200 GeV < 2.0 * 10^(-3) erg cm^(-2) (Assuming z=2.0)
  These upper limits are preliminary and will be refined with further analysis.
• GCN Circular #7005
  Adria C. Updike, Dieter H. Hartmann (Clemson University), Evan Bryson, Matt Cefalu, and Todd Hillwig (Valparaiso University) report on behalf of the Clemson GRB Follow-Up Team:
  We observed the field of GRB 071025 (GCN 6986, Pagani et al.) with the 0.9m SARA telescope on Kitt Peak beginning 49 minutes after the trigger. Our observations consisted of R, V, and I band exposures under good weather conditions. We do not detect the afterglow (GCN 6987, Rykoff et al.) in any of our stacked images.
  Times are given in days after the trigger. R and I magnitudes were determined based on calibration to 10 USNO B1.0 field stars. V magnitudes were found relative to 5 NOMAD field stars.

  Start time       End time      Exp                  Mag
  ----------------------------------------------------------
  0.03394         0.04328      4x180s               R > 18.6
  0.04405         0.05559      2x180s + 2x240s      V > 19.1
  0.05586         0.10521      10x240s              I > 19.3
  

  The SARA website may be found at http://astro.fit.edu/sara/sara.html
  This message may be cited.
• GCN Report 97.1
  GCN_Report 97.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_97_1.pdf by C. Pagani at PSU titled: "Swift Observations of GRB 071025"
• GCN Circular #7008
  J. Wren, W.T. Vestrand, P.R. Wozniak, R. White, H. Davis of Los Alamos National Laboratory report:
  Our Raptor telescopes responded to Swift trigger 295301 (Pagani et al., GCN 6986) at 04:10:14.0 UT, 80.3 seconds after the trigger and 4.2 seconds after receiving the GCN packet. We detect faint optical emission from the counterpart reported by the ROTSE team (Rykoff et al., GCN 6987 and Covino et al., GCN 6988). We observe the first optical peak reported by Rykoff et al. (GCN 6992) at T+~600s. The counterpart then fades until T+~1200s. The optical lightcurve then rebrightens to a peak near T+~1400s at about the level of the previous peak. This "twin peaks" behavior seems to be consistent with the IR behavior reported by Bloom et al. (GCN 7002).
• GCN Circular #7011
  P. A. Milne (Steward Observatory) and G. G. Williams (MMTO), on behalf of the Super-LOTIS Collaboration, report:
  The 1.54m Kuiper telescope began observations of the error region of GRB 071025 (Swift trigger 295301, Pagani et al. GCN 6986) at 04:37:08 UT, approximately 28 minutes after the trigger. Observations were obtained in the V, R, and I-bands. The afterglow first reported by Rykoff et al. (GCN 6987) is clearly visible in the individual early R and I band images but not in the V-band images or in the sum of the V-band images. Observations continued until 09:47:09 UT.
  The aperture photometry results below were obtained from sums of individual images using nearby stars in the USNO-B1.0 and NOMAD catalogs. Further analysis of additional epochs is continuing.

  Filter UT-Start       UT-End        exp (s) magnitude error
  R ---- 04:37:08 ----- 04:41:30 ---- 150 --- 18.7 +/- 0.1
  R ---- 04:42:14 ----- 05:02:40 ---- 1080 -- 19.3 +/- 0.1
  R ---- 05:03:12 ----- 05:24:11 ---- 1080 -- 19.8 +/- 0.1
  
  V ---- 05:43:38 ----- 06:07:46 ---- 1200 -- < 22.0
  
  I ---- 05:25:05 ----- 05:42:39 ---- 960 -- 18.2 +/- 0.1
  I ---- 08:01:20 ----- 08:55:41 ---- 3000 -- 19.9 +/- 0.15
  

  This message may be cited.
• GCN Circular #7018
  T. Minezaki (IoA, Tokyo), P.A. Price (IfA, Hawaii), Y. Yoshii (IoA, Tokyo), L. Cowie (IfA, Hawaii) and Y. Kakazu (IfA, Hawaii) report:
  We observed the optical afterglow of GRB071025 with the robotic MAGNUM telescope + MIPS dual-beam imager. We find a fading source in each of the RIYJHK bands at the position reported by Bloom et al. (GCN 6989):

   Filter  midtime(UTC)       Exp. time    magnitude/upper limits
     J     2007-10-25 06:59   10           17.73 +- 0.06
     R     2007-10-25 07:01   10           21.5  +- 0.4
     Y     2007-10-25 07:21    9           detected
     I     2007-10-25 07:21   10           19.97 +- 0.13
     K     2007-10-25 07:43    8           16.67 +- 0.07
     R     2007-10-25 07:43   10           > 20.9
     H     2007-10-25 08:04    9           17.59 +- 0.08
     I     2007-10-25 08:04   10           20.3 +- 0.2
     J     2007-10-25 08:25    9           18.29 +- 0.10
     R     2007-10-25 08:25   10           > 21.0
     Y     2007-10-25 08:44    9           marginally detected
     I     2007-10-25 08:44   10           20.5 +- 0.3
  

  The magnitude and the 3-sigma upper limits were derived using the USNO-B1.0 and 2MASS catalogues. The magnitude error does not include the error of the calibration source. The Y-band observations have not been calibrated.
  This message may be cited.
• Redshift of z = 5.2
  0907.3449 from 20 Jul 2009
  Fynbo et al: Low-Resolution Spectroscopy of Gamma-ray Burst Optical Afterglows: Biases in the Swift Sample and Characterization of the Absorbers
  Abstract: (Abridged). We present a sample of 77 optical afterglows (OAs) of Swift detected GRBs for which spectroscopic follow-up observations have been secured. We provide linelists and equivalent widths for all detected lines redward of Ly-alpha. We discuss to what extent the current sample of Swift bursts with OA spectroscopy is a biased subsample of all Swift detected GRBs. For that purpose we define an X-ray selected sample of Swift bursts with optimal conditions for ground-based follow up from the period March 2005 to September 2008; 146 bursts fulfill our sample criteria. We derive the redshift distribution for this sample and conclude that less than 19% of Swift bursts are at z>7. We compare the high energy properties for three sub-samples of bursts in the sample: i) bursts with redshifts measured from OA spectroscopy, ii) bursts with detected OA, but no OA-based redshift, and iii) bursts with no detection of the OA. The bursts in group i) have significantly less excess X-ray absorption than bursts in the other two groups. In addition, the fraction of dark bursts is 14% in group i), 38% in group ii) and > 39% in group iii). From this we conclude that the sample of GRBs with OA spectroscopy is not representative for all Swift bursts, most likely due to a bias against the most dusty sight-lines. Finally, we characterize GRB absorption systems as a class and compare them to QSO absorption systems, in particular DLAs. On average GRB absorbers are characterized by significantly stronger EWs for HI as well as for both low and high ionization metal lines than what is seen in intervening QSO absorbers. Based on the z>2 bursts in the sample we place a 95% confidence upper limit of 7.5% on the mean escape fraction of ionizing photons from star-forming galaxies.
• Photometric redshift of z ~ 5
  0912.2999 from 14 Dec 2009
  Perley et al: Evidence for Supernova-synthesised dust from the late-rising afterglow of GRB 071025 at z~5
  We present observations and analysis of the broadband afterglow of Swift GRB 071025. Using optical and infrared (RIYJHK) photometry, we derive a photometric redshift of 4.4 < z < 5.2; at this redshift our simultaneous multicolour observations begin at ~30 s after the GRB trigger in the host frame and during the initial rising phase of the afterglow. We associate the light curve peak at 580 s in the observer frame with the formation of the forward shock, giving an estimate of the initial Lorentz factor Gamma_0 ~ 200. The red spectral energy distribution (even in regions not affected by the Lyman-alpha break) provides secure evidence of a large dust column. However, the inferred extinction curve shows a prominent flat component between 2000-3000 Angstroms in the rest-frame, inconsistent with any locally observed template but well-fit by models of dust formed by supernovae. Time-dependent fits to the extinction profile reveal no evidence of dust destruction and limit the decrease in the extinction column to Delta A_3000 < 0.54 mag after t = 50 s in the rest frame. Our observations provide evidence of a transition in dust properties at z~5, in agreement with studies of high-z quasars, and suggests that SN-formed dust continues to dominate the opacity of typical galaxies at this redshift.
• 1110.3259 from 17 Oct 2011
  M. Jang et al.: Dust properties in afterglow of GRB 071025 at z ~ 5
  At high redshift, the universe was so young that core-collap se supernovae (SNe) are suspected to be the dominant source of dust production. Howe ver, some observations indicate that the dust production by SNe is an inefficient proc ess, casting doubts on the existence of abundant SNe-dust in the early universe. Re cently, Perley et al. (2010) reported that the afterglow of GRB 071025 - an unusually red GRB at z~5 - shows evidence for the SNe-produced dust. Since this is perhaps the only high redshift GRB exhibiting compelling evidence for SNe-dust but the result could easily be affected by small systematics in photometry, we re-examined the extinction properties of GRB 071025 using our own optical/near-infrared data at a different epoch. In addition, we tested SNe-dust models with different progenitor masses and dust destruction efficiencies to constrain the dust formation mechanisms. By searching for the best-fit model of the afterglow spectral energy distribution, we confirm the previous claim that the dust in GRB 071025 is most likely to originate from SNe. We also find that the SNe-dust model of 13 or 25 Msun without dust destruction fits the extinction property of GRB 071025 best, while pair-instability SNe (PISNe) models with a 170Msun progenitor poorly fit the data. Our results indicate that, at least in some systems at high redshift, SNe with intermediate masses within 10-30Msun were the main contributors for the dust enrichment, and the dust destruction effect due to reverse shock was negligible.