Gamma-ray Burst 100725A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 25 Jul 10 07:13:12 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     429954,   Seg_Num: 0
GRB_RA:          166.515d {+11h 06m 04s} (J2000),
                 166.643d {+11h 06m 34s} (current),
                 165.908d {+11h 03m 38s} (1950)
GRB_DEC:         -26.688d {-26d 41' 14"} (J2000),
                 -26.745d {-26d 44' 40"} (current),
                 -26.417d {-26d 25' 01"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       4848 [cnts]    Image_Peak=173 [image_cnts]
TRIGGER_DUR:     1.024 [sec]
TRIGGER_INDEX:   155     E_range: 50-350 keV
BKG_INTEN:       26029 [cnts]
BKG_TIME:        25953.98 SOD {07:12:33.98} UT
BKG_DUR:         8 [sec]
GRB_DATE:        15402 TJD;   206 DOY;   10/07/25
GRB_TIME:        25972.41 SOD {07:12:52.41} UT
GRB_PHI:         -157.77 [deg]
GRB_THETA:        30.64 [deg]
SOLN_STATUS:     0x83
RATE_SIGNIF:     24.65 [sigma]
IMAGE_SIGNIF:    6.66 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +3  -4  +0  +0 -47  +0
SUN_POSTN:       124.52d {+08h 18m 05s}  +19.66d {+19d 39' 20"}
SUN_DIST:         61.81 [deg]   Sun_angle= -2.8 [hr] (East of Sun)
MOON_POSTN:      295.33d {+19h 41m 20s}  -20.26d {-20d 15' 25"}
MOON_DIST:       111.59 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      275.53, 30.52 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      179.18,-29.67 [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 = 98.81,-6.94 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 25 Jul 10 07:14:37 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     429954,   Seg_Num: 0
GRB_RA:          166.4839d {+11h 05m 56.13s} (J2000),
                 166.6123d {+11h 06m 26.96s} (current),
                 165.8766d {+11h 03m 30.38s} (1950)
GRB_DEC:         -26.6716d {-26d 40' 17.7"} (J2000),
                 -26.7288d {-26d 43' 43.6"} (current),
                 -26.4013d {-26d 24' 04.5"} (1950)
GRB_ERROR:       5.4 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.32e-09 [erg/cm2/sec]
GRB_SIGNIF:      7.34 [sigma]
IMG_START_DATE:  15402 TJD;   206 DOY;   10/07/25
IMG_START_TIME:  26049.08 SOD {07:14:09.08} UT,   76.7 [sec] since BAT Trigger Time
TAM[0-3]:        327.71 237.23 261.64 243.24
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       124.52d {+08h 18m 06s}  +19.66d {+19d 39' 19"}
SUN_DIST:         61.78 [deg]   Sun_angle= -2.8 [hr] (East of Sun)
MOON_POSTN:      295.35d {+19h 41m 23s}  -20.25d {-20d 15' 13"}
MOON_DIST:       111.63 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      275.49, 30.52 [deg] galactic lon,lat of the burst
ECL_COORDS:      179.14,-29.66 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.
COMMENTS:        The XRT position is 1.92 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 25 Jul 10 07:14:47 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     429954,   Seg_Num: 0
GRB_RA:          166.4839d {+11h 05m 56.1s} (J2000),
                 166.6123d {+11h 06m 26.9s} (current),
                 165.8766d {+11h 03m 30.3s} (1950)
GRB_DEC:         -26.6716d {-26d 40' 17.7"} (J2000),
                 -26.7288d {-26d 43' 43.6"} (current),
                 -26.4013d {-26d 24' 04.5"} (1950)
GRB_ERROR:       5.0 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       54 [cnts]
IMG_START_DATE:  15402 TJD;   206 DOY;   10/07/25
IMG_START_TIME:  26049.08 SOD {07:14:09.08} UT,   76.7 [sec] since BAT Trigger Time
CENTROID_X:      215.79,  raw= 216  [pixels]
CENTROID_Y:      304.03,  raw= 304  [pixels]
ROLL:            314.26 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   14.21
GRB_POS_XRT_Z:   -203.92
IMAGE_URL:       sw00429954000msxps_rw.img
SUN_POSTN:       124.52d {+08h 18m 06s}  +19.66d {+19d 39' 19"}
SUN_DIST:         61.78 [deg]   Sun_angle= -2.8 [hr] (East of Sun)
MOON_POSTN:      295.35d {+19h 41m 23s}  -20.25d {-20d 15' 12"}
MOON_DIST:       111.63 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      275.49, 30.52 [deg] galactic lon,lat of the burst
ECL_COORDS:      179.14,-29.66 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 25 Jul 10 07:14:54 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     429954,   Seg_Num: 0
GRB_RA:          166.4839d {+11h 05m 56.1s} (J2000),
                 166.6123d {+11h 06m 26.9s} (current),
                 165.8766d {+11h 03m 30.3s} (1950)
GRB_DEC:         -26.6716d {-26d 40' 17.7"} (J2000),
                 -26.7288d {-26d 43' 43.6"} (current),
                 -26.4013d {-26d 24' 04.5"} (1950)
GRB_ERROR:       5.0 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       54 [cnts]
IMG_START_DATE:  15402 TJD;   206 DOY;   10/07/25
IMG_START_TIME:  26049.08 SOD {07:14:09.08} UT,   76.7 [sec] since BAT Trigger Time
CENTROID_X:      215.79,  raw= 216  [pixels]
CENTROID_Y:      304.03,  raw= 304  [pixels]
ROLL:            314.26 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   14.21
GRB_POS_XRT_Z:   -203.92
IMAGE_URL:       sw00429954000msxps_rw.img
SUN_POSTN:       124.52d {+08h 18m 06s}  +19.66d {+19d 39' 19"}
SUN_DIST:         61.78 [deg]   Sun_angle= -2.8 [hr] (East of Sun)
MOON_POSTN:      295.35d {+19h 41m 23s}  -20.25d {-20d 15' 11"}
MOON_DIST:       111.63 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      275.49, 30.52 [deg] galactic lon,lat of the burst
ECL_COORDS:      179.14,-29.66 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 25 Jul 10 07:16:41 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     429954,   Seg_Num: 0
GRB_RA:          166.515d {+11h 06m 04s} (J2000),
                 166.643d {+11h 06m 34s} (current),
                 165.908d {+11h 03m 38s} (1950)
GRB_DEC:         -26.688d {-26d 41' 14"} (J2000),
                 -26.745d {-26d 44' 40"} (current),
                 -26.417d {-26d 25' 01"} (1950)
GRB_DATE:        15402 TJD;   206 DOY;   10/07/25
GRB_TIME:        25972.41 SOD {07:12:52.41} UT
TRIGGER_INDEX:   155
GRB_PHI:         -157.77 [deg]
GRB_THETA:        30.64 [deg]
DELTA_TIME:      77.00 [sec]
TRIGGER_DUR:     1.024 [sec]
SOLN_STATUS:     0x83
RATE_SIGNIF:     24.65 [sigma]
IMAGE_SIGNIF:    6.66 [sigma]
LC_URL:          sw00429954000msb.lc
SUN_POSTN:       124.52d {+08h 18m 06s}  +19.66d {+19d 39' 18"}
SUN_DIST:         61.81 [deg]   Sun_angle= -2.8 [hr] (East of Sun)
MOON_POSTN:      295.36d {+19h 41m 27s}  -20.25d {-20d 14' 57"}
MOON_DIST:       111.61 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      275.53, 30.52 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      179.18,-29.67 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Lightcurve.
COMMENTS:        This Notice is generated as a result of an uploaded TOO -- this is not a normal BAT-detected burst.
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 = 98.81,-6.94 [deg].

GCN Circular #10979
C. B. Markwardt (CRESST/GSFC/UMD), J. M. Gelbord (PSU), V. Mangano (INAF-IASFPA), K. L. Page (U Leicester), D. M. Palmer (LANL), T. A. Pritchard (PSU) and B. Sbarufatti (INAF-OAB/IASFPA) report on behalf of the Swift Team:
At 07:12:52 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 100725A (trigger=429954). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 166.515, -26.688 which is
```
   RA(J2000) = 11h 06m 04s
   Dec(J2000) = -26d 41' 14"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a multi-peaked structure with a duration of at least 40 sec. The peak count rate was ~3000 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 07:14:09.1 UT, 76.7 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 166.4839, -26.6716 which is equivalent to:
```
   RA(J2000)  = 11h 05m 56.13s
   Dec(J2000) = -26d 40' 17.7"
```
with an uncertainty of 5.4 arcseconds (radius, 90% containment). This location is 115 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy.
The initial flux in the 2.5 s image was 1.32e-09 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of nominal 150 seconds with the White filter starting 84 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. Data from the 2.7'x2.7' sub-image are not available at this time. 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 0.05.
Burst Advocate for this burst is C. B. Markwardt (Craig.Markwardt AT nasa.gov). 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:     Sun 25 Jul 10 07:27:24 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     429954,   Seg_Num: 0
POINT_RA:        166.535d {+11h 06m 08s} (J2000)
POINT_DEC:       -26.708d {-26d 42' 27"} (J2000)
ROLL:            314.264d
IMG_START_DATE:  15402 TJD;   206 DOY;   10/07/25
IMG_START_TIME:  26269.31 SOD {07:17:49.31} UT,   296.9 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     301735075
X_OFFSET:        1142 [pixels]
Y_OFFSET:        637 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1302
Y_GRB_POS:       797
BINNING_INDEX:   1
IM_URL:          sw00429954000msuni0303.fits
SUN_POSTN:       124.53d {+08h 18m 08s}  +19.65d {+19d 39' 12"}
SUN_DIST:         61.83 [deg]   Sun_angle= -2.8 [hr] (East of Sun)
MOON_POSTN:      295.46d {+19h 41m 50s}  -20.23d {-20d 13' 33"}
MOON_DIST:       111.67 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      275.56, 30.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      179.20,-29.68 [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:     Sun 25 Jul 10 07:27:33 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     429954,   Seg_Num: 0
GRB_RA:          166.4815d {+11h 05m 55.56s} (J2000),
                 166.6099d {+11h 06m 26.38s} (current),
                 165.8742d {+11h 03m 29.80s} (1950)
GRB_DEC:         -26.6703d {-26d 40' 13.0"} (J2000),
                 -26.7275d {-26d 43' 38.9"} (current),
                 -26.4000d {-26d 23' 59.8"} (1950)
GRB_ERROR:       2.3 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  15402 TJD;   206 DOY;   10/07/25
IMG_START_TIME:  26239.00 SOD {07:17:19.00} UT,   266.6 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       124.53d {+08h 18m 08s}  +19.65d {+19d 39' 12"}
SUN_DIST:         61.77 [deg]   Sun_angle= -2.8 [hr] (East of Sun)
MOON_POSTN:      295.46d {+19h 41m 50s}  -20.23d {-20d 13' 32"}
MOON_DIST:       111.73 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      275.49, 30.52 [deg] galactic lon,lat of the burst
ECL_COORDS:      179.14,-29.66 [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/docs.php for details.  
COMMENTS:        This position was enhanced using UVOT field astrometry.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.58% < P(seren) < 1.1%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 25 Jul 10 07:27:43 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     429954,   Seg_Num: 0
POINT_RA:        166.535d {+11h 06m 08s} (J2000)
POINT_DEC:       -26.708d {-26d 42' 27"} (J2000)
ROLL:            314.264d
IMG_START_DATE:  15402 TJD;   206 DOY;   10/07/25
IMG_START_TIME:  26269.31 SOD {07:17:49.31} UT,   296.9 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     301735075
X_OFFSET:        1142 [pixels]
Y_OFFSET:        637 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1302
Y_GRB_POS:       797
BINNING_INDEX:   1
IM_URL:          sw00429954000msuni0303.fits
SUN_POSTN:       124.53d {+08h 18m 08s}  +19.65d {+19d 39' 12"}
SUN_DIST:         61.83 [deg]   Sun_angle= -2.8 [hr] (East of Sun)
MOON_POSTN:      295.46d {+19h 41m 50s}  -20.23d {-20d 13' 31"}
MOON_DIST:       111.67 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      275.56, 30.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      179.20,-29.68 [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:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 25 Jul 10 07:34:06 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     429954,   Seg_Num: 0
POINT_RA:        166.535d {+11h 06m 08s} (J2000)
POINT_DEC:       -26.708d {-26d 42' 27"} (J2000)
POINT_ROLL:      314.264d
IMG_START_DATE:  15402 TJD;   206 DOY;   10/07/25
IMG_START_TIME:  26845.59 SOD {07:27:25.59} UT,   873.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.075
N_STARS:         190
X_OFFSET:        582 [pixels]
Y_OFFSET:        77 [pixels]
X_MAX:           2021 [pixels]
Y_MAX:           1516 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    8
SL_URL:          sw00429954000msufc0873.fits
SUN_POSTN:       124.54d {+08h 18m 09s}  +19.65d {+19d 39' 09"}
SUN_DIST:         61.82 [deg]   Sun_angle= -2.8 [hr] (East of Sun)
MOON_POSTN:      295.51d {+19h 42m 04s}  -20.21d {-20d 12' 41"}
MOON_DIST:       111.72 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      275.56, 30.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      179.20,-29.68 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 25 Jul 10 07:34:06 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     429954,   Seg_Num: 0
POINT_RA:        166.535d {+11h 06m 08s} (J2000)
POINT_DEC:       -26.708d {-26d 42' 27"} (J2000)
POINT_ROLL:      314.264d
IMG_START_DATE:  15402 TJD;   206 DOY;   10/07/25
IMG_START_TIME:  26845.59 SOD {07:27:25.59} UT,   873.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.075
N_STARS:         190
X_OFFSET:        582 [pixels]
Y_OFFSET:        77 [pixels]
X_MAX:           2021 [pixels]
Y_MAX:           1516 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    8
SL_URL:          sw00429954000msufc0873.fits
SUN_POSTN:       124.54d {+08h 18m 09s}  +19.65d {+19d 39' 09"}
SUN_DIST:         61.82 [deg]   Sun_angle= -2.8 [hr] (East of Sun)
MOON_POSTN:      295.51d {+19h 42m 04s}  -20.21d {-20d 12' 41"}
MOON_DIST:       111.72 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      275.56, 30.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      179.20,-29.68 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 25 Jul 10 07:35:26 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     429954,   Seg_Num: 0
POINT_RA:        166.535d {+11h 06m 08s} (J2000)
POINT_DEC:       -26.708d {-26d 42' 27"} (J2000)
ROLL:            314.264d
IMG_START_DATE:  15402 TJD;   206 DOY;   10/07/25
IMG_START_TIME:  26845.59 SOD {07:27:25.59} UT,   873.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     301735651
X_OFFSET:        1141 [pixels]
Y_OFFSET:        636 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1301
Y_GRB_POS:       796
BINNING_INDEX:   1
IM_URL:          sw00429954000msuni0880.fits
SUN_POSTN:       124.54d {+08h 18m 09s}  +19.65d {+19d 39' 08"}
SUN_DIST:         61.82 [deg]   Sun_angle= -2.8 [hr] (East of Sun)
MOON_POSTN:      295.53d {+19h 42m 06s}  -20.21d {-20d 12' 30"}
MOON_DIST:       111.73 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      275.56, 30.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      179.20,-29.68 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 25 Jul 10 07:35:42 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     429954,   Seg_Num: 0
POINT_RA:        166.535d {+11h 06m 08s} (J2000)
POINT_DEC:       -26.708d {-26d 42' 27"} (J2000)
ROLL:            314.264d
IMG_START_DATE:  15402 TJD;   206 DOY;   10/07/25
IMG_START_TIME:  26845.59 SOD {07:27:25.59} UT,   873.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     301735651
X_OFFSET:        1141 [pixels]
Y_OFFSET:        636 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1301
Y_GRB_POS:       796
BINNING_INDEX:   1
IM_URL:          sw00429954000msuni0880.fits
SUN_POSTN:       124.54d {+08h 18m 09s}  +19.65d {+19d 39' 08"}
SUN_DIST:         61.82 [deg]   Sun_angle= -2.8 [hr] (East of Sun)
MOON_POSTN:      295.53d {+19h 42m 07s}  -20.21d {-20d 12' 28"}
MOON_DIST:       111.73 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      275.56, 30.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      179.20,-29.68 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN Circular #10980
P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:
Using promptly downlinked XRT event data for GRB 100725A, we find an enhanced XRT position of the afterglow: RA, Dec: 166.4815, -26.6703 which is equivalent to:
```
   RA (J2000)  = 11 05 55.57
   Dec (J2000) = -26 40 12.9
```
with an uncertainty of 2.2 arc sec (radius, 90% confidence). Analysis of the promptly available data is online at http://www.swift.ac.uk/sper/429954.
Position enhancement is is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177).
This circular is an official product of the Swift-XRT team.
GCN Circular #10982
D. Bersier, C. Guidorzi, Z. Cano, S. Kobayashi report on behalf of a larger collaboration:
We observed the location of GRB100725A (GCN 10979) with the Faulkes Telescope South, starting at the beginning of the night (1.7 hour after trigger). In a 5 minutes R-band exposure, we do not detect any source not present on the DSS inside the enhanced XRT error circle (GCN 10980). Any source at m=20.0 would have been clearly detected. The same holds for a 6x5minutes exposure at a magnitude m=21.3.
GCN Circular #10985
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team.
Using 1441 s of XRT Photon Counting mode data and 1 UVOT images for GRB 100725A, 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 = 166.48153, -26.67025 which is equivalent to:
```
RA (J2000): 11h 05m 55.57s
Dec (J2000): -26d 40' 12.9"
```
with an uncertainty of 1.8 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177).
This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN Circular #10987
B. Sbarufatti (INAF OAB/INAF IASF-PA) , V. Mangano (INAF/IASF_PA) and C. B. Markwardt (CRESST/GSFC/UMD) report on behalf of the Swift-XRT team:
We have analysed 4.3 ks of XRT data for GRB 100725A (Markwardt et al. GCN Circ. 10979), from 82 s to 11.0 ks after the BAT trigger. The data comprise 177 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The light curve can be modelled with an initial power-law decay with an index of alpha=1.1 (+/-0.1), followed by a break at T+270 s to an alpha of 6.5 (+/-0.5). After a second break at T+590 s the decay follows an index of alpha=0.9 (+0.3 -0.4).
The spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.18 (+/-0.08). The best-fitting absorption column is 1.2 (+/-0.3) x 10^21 cm^-2, in excess of the Galactic value of 4.6 x 10^20 cm^-2 (Kalberla et al. 2005). The spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.20 (+/-0.09). The best-fitting absorption column is 8.9 (+10.0 -0.8) x 10^20 cm^-2, marginally in excess of the Galactic value. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor is 6.2 x 10^-11 (6.7 x 10^-11) ergcm^-2 count^-1.
If the light curve continues to decay with a power-law decay index of 0.9, the count rate at T+24 hours will be 2.4 x 10^-4 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.4 x 10^-14 (1.6 x 10^-14) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00429954.
This circular is an official product of the Swift-XRT team.
GCN Circular #10988
D. M. Palmer (LANL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), T. Sakamoto (GSFC/UMBC), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+903 sec from recent telemetry downlinks, we report further analysis of BAT GRB 100725A (trigger #429954) (Markwardt, et al., GCN Circ. 10979). The BAT ground-calculated position is RA, Dec = 166.468, -26.667 deg, which is
```
   RA(J2000)  =  11h 05m 52.2s 
   Dec(J2000) = -26d 39' 59.9" 
```
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 82%.
The mask-weighted light curve shows many overlapping peaks starting at ~T-3 sec, with the highest peak at ~T+9 sec, and ending at ~T+200 sec. T90 (15-350 keV) is 141 +- 27 sec (estimated error including systematics).
The time-averaged spectrum from T-4.8 to T+172.0 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.23 +- 0.12. The fluence in the 15-150 keV band is 2.0 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+8.58 sec in the 15-150 keV band is 0.7 +- 0.1 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/429954/BA/
GCN Circular #10989
GRB 100725A: Swift/UVOT Upper Limits
T. A. Pritchard (PSU) and C. B. Markwardt (CRESST/GSFC/UMD) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 100725A 85 s after the BAT trigger (Markwardt et al., GCN Circ. 10979). No optical afterglow consistent with the XRT position (Evans et al., GCN Circ. 10985) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) for the first finding chart (FC) exposure and subsequent exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC            85          234          147 >20.7
u_FC               297          547          246 >20.3
white               85        11646         1486 >21.8
v                  626        13269         1202 >20.2
b                  552         7488          440 >20.6
u                  297         7353          736 >20.5
w1                 675         7148          510 >20.4
m2                 651         6942          510 >20.3
w2                 602        12552         1396 >21.2
```
The values quoted above are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.05 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #10991
F. Olivares E. (MPE Garching), S. Klose (Tautenburg), and J. Greiner (MPE Garching) report on behalf of the GROND team:
GROND (Greiner et al. 2008, PASP 120, 405), the 7-channel imager mounted at the 2.2m ESO/MPI telescope on La Silla, started follow-up observations of GRB 100725A (Markwardt et al. 2010, GCN 10979) on July 25 at 23:05 UT (about 16 hrs after the trigger).
With a total integration time of 24.4 min in the optical and 20 min in the nIR, we do not detect any source within the 1.8-arcsec XRT error circle (Evans et al. 2010, GCN 10985) down to the following upper limits (AB system):
```
g' > 22.8
r' > 23.3
i' > 23.1
z' > 22.9
J > 21.7
H > 21.1
K > 20.4,
```
The given limits are calibrated againt GROND zeropoints and 2MASS field stars and are not corrected for the Galactic foreground extinction corresponding to a reddening of E(B-V)=3D 0.052 in the direction of the burst (Schlegel et al. 1998).

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Jochen Greiner, last update: 25-Jul-2010 [Disclaimer]