Gamma-ray Burst 100625A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

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Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Jun 10 18:32:45 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     425647,   Seg_Num: 0
GRB_RA:           15.771d {+01h 03m 05s} (J2000),
                  15.892d {+01h 03m 34s} (current),
                  15.191d {+01h 00m 46s} (1950)
GRB_DEC:         -39.083d {-39d 04' 57"} (J2000),
                 -39.027d {-39d 01' 35"} (current),
                 -39.351d {-39d 21' 03"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       3518 [cnts]    Image_Peak=381 [image_cnts]
TRIGGER_DUR:     0.256 [sec]
TRIGGER_INDEX:   126     E_range: 50-350 keV
BKG_INTEN:       25475 [cnts]
BKG_TIME:        66738.07 SOD {18:32:18.07} UT
BKG_DUR:         8 [sec]
GRB_DATE:        15372 TJD;   176 DOY;   10/06/25
GRB_TIME:        66748.37 SOD {18:32:28.37} UT
GRB_PHI:         -17.28 [deg]
GRB_THETA:         2.05 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     93.24 [sigma]
IMAGE_SIGNIF:    15.27 [sigma]
MERIT_PARAMS:     +1  +0  +0  -2  +3  +4  +0  +0 +11  +0
SUN_POSTN:        94.46d {+06h 17m 50s}  +23.37d {+23d 22' 27"}
SUN_DIST:         96.22 [deg]   Sun_angle= 5.2 [hr] (West of Sun)
MOON_POSTN:      265.34d {+17h 41m 22s}  -24.75d {-24d 44' 52"}
MOON_DIST:        89.09 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      292.18,-77.80 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      355.62,-41.48 [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 = 230.64,-20.56 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Fri 25 Jun 10 18:32:47 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      45
TRIGGER_NUM:     299183550
GRB_RA:           16.300d {+01h 05m 12s} (J2000),
                  16.421d {+01h 05m 41s} (current),
                  15.724d {+01h 02m 54s} (1950)
GRB_DEC:         -40.000d {-40d 00' 00"} (J2000),
                 -39.944d {-39d 56' 37"} (current),
                 -40.268d {-40d 16' 02"} (1950)
GRB_ERROR:       4.82 [deg radius, statistical plus systematic]
GRB_INTEN:       1181 [cnts/sec]
DATA_SIGNIF:     13.90 [sigma]
INTEG_TIME:      0.256 [sec]
GRB_DATE:        15372 TJD;   176 DOY;   10/06/25
GRB_TIME:        66748.47 SOD {18:32:28.47} UT
GRB_PHI:         292.00 [deg]
GRB_THETA:       125.00 [deg]
DATA_TIME_SCALE: 0.2560 [sec]
HARD_RATIO:      0.51
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      64%  Distant Particles
2nd_MOST_LIKELY:  34%  GRB
DETECTORS:       0,1,0, 0,1,1, 0,0,1, 0,0,0, 0,0,
SUN_POSTN:        94.46d {+06h 17m 50s}  +23.37d {+23d 22' 27"}
SUN_DIST:         96.25 [deg]   Sun_angle= 5.2 [hr] (West of Sun)
MOON_POSTN:      265.34d {+17h 41m 22s}  -24.75d {-24d 44' 52"}
MOON_DIST:        88.95 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      291.30,-76.82 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      355.46,-42.48 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 251.48,25.43 [deg].

GCN NOTICE

TITLE:          GCN/INTEGRAL NOTICE
NOTICE_DATE:    Fri 25 Jun 10 18:33:10 UT
NOTICE_TYPE:    INTEGRAL SPI ACS Trigger
TRIGGER_NUM:    6030,   Sub_Num: 0
GRB_INTEN:      12.13 [sigma]
GRB_TIME:       66748.53 SOD {18:32:28.53} UT
GRB_DATE:       15372 TJD;   176 DOY;   10/06/25
COMMENTS:       INTEGRAL SPI_ACS GRB Trigger.
COMMENTS:
COMMENTS:       NOTE: This SPIACS event is temporally(0.0<100sec) coincident with the SWIFT_BAT event (trignum=425647).
COMMENTS:
COMMENTS:       The SPIACS lightcurve can be found at:
COMMENTS:       ftp://isdcarc.unige.ch/arc/FTP/ibas/spiacs/2010-06/2010-06-25T18-32-28.3783-13288-00007-0.lc

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Jun 10 18:33:55 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     425647,   Seg_Num: 0
GRB_RA:           15.7968d {+01h 03m 11.23s} (J2000),
                  15.9182d {+01h 03m 40.35s} (current),
                  15.2170d {+01h 00m 52.09s} (1950)
GRB_DEC:         -39.0949d {-39d 05' 41.6"} (J2000),
                 -39.0388d {-39d 02' 19.5"} (current),
                 -39.3632d {-39d 21' 47.4"} (1950)
GRB_ERROR:       5.8 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       7.93e-10 [erg/cm2/sec]
GRB_SIGNIF:      4.47 [sigma]
IMG_START_DATE:  15372 TJD;   176 DOY;   10/06/25
IMG_START_TIME:  66796.66 SOD {18:33:16.66} UT,   48.3 [sec] since BAT Trigger Time
TAM[0-3]:        327.67 237.23 261.41 243.75
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:        94.46d {+06h 17m 50s}  +23.37d {+23d 22' 27"}
SUN_DIST:         96.21 [deg]   Sun_angle= 5.2 [hr] (West of Sun)
MOON_POSTN:      265.35d {+17h 41m 24s}  -24.75d {-24d 44' 50"}
MOON_DIST:        89.09 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      292.10,-77.79 [deg] galactic lon,lat of the burst
ECL_COORDS:      355.64,-41.50 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 1.40 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Jun 10 18:34:09 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     425647,   Seg_Num: 0
GRB_RA:           15.7968d {+01h 03m 11.2s} (J2000),
                  15.9182d {+01h 03m 40.3s} (current),
                  15.2170d {+01h 00m 52.0s} (1950)
GRB_DEC:         -39.0949d {-39d 05' 41.6"} (J2000),
                 -39.0388d {-39d 02' 19.5"} (current),
                 -39.3632d {-39d 21' 47.4"} (1950)
GRB_ERROR:       5.8 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       20 [cnts]
IMG_START_DATE:  15372 TJD;   176 DOY;   10/06/25
IMG_START_TIME:  66796.66 SOD {18:33:16.66} UT,   48.3 [sec] since BAT Trigger Time
CENTROID_X:      279.26,  raw= 279  [pixels]
CENTROID_Y:      267.85,  raw= 268  [pixels]
ROLL:            64.91 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -71.05
GRB_POS_XRT_Z:   -54.29
IMAGE_URL:       sw00425647000msxps_rw.img
SUN_POSTN:        94.46d {+06h 17m 50s}  +23.37d {+23d 22' 27"}
SUN_DIST:         96.21 [deg]   Sun_angle= 5.2 [hr] (West of Sun)
MOON_POSTN:      265.35d {+17h 41m 25s}  -24.75d {-24d 44' 49"}
MOON_DIST:        89.09 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      292.10,-77.79 [deg] galactic lon,lat of the burst
ECL_COORDS:      355.64,-41.50 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Jun 10 18:34:04 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     425647,   Seg_Num: 0
GRB_RA:           15.7968d {+01h 03m 11.2s} (J2000),
                  15.9182d {+01h 03m 40.3s} (current),
                  15.2170d {+01h 00m 52.0s} (1950)
GRB_DEC:         -39.0949d {-39d 05' 41.6"} (J2000),
                 -39.0388d {-39d 02' 19.5"} (current),
                 -39.3632d {-39d 21' 47.4"} (1950)
GRB_ERROR:       5.8 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       20 [cnts]
IMG_START_DATE:  15372 TJD;   176 DOY;   10/06/25
IMG_START_TIME:  66796.66 SOD {18:33:16.66} UT,   48.3 [sec] since BAT Trigger Time
CENTROID_X:      279.26,  raw= 279  [pixels]
CENTROID_Y:      267.85,  raw= 268  [pixels]
ROLL:            64.91 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -71.05
GRB_POS_XRT_Z:   -54.29
IMAGE_URL:       sw00425647000msxps_rw.img
SUN_POSTN:        94.46d {+06h 17m 50s}  +23.37d {+23d 22' 27"}
SUN_DIST:         96.21 [deg]   Sun_angle= 5.2 [hr] (West of Sun)
MOON_POSTN:      265.35d {+17h 41m 25s}  -24.75d {-24d 44' 50"}
MOON_DIST:        89.09 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      292.10,-77.79 [deg] galactic lon,lat of the burst
ECL_COORDS:      355.64,-41.50 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Jun 10 18:36:11 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     425647,   Seg_Num: 0
GRB_RA:           15.771d {+01h 03m 05s} (J2000),
                  15.892d {+01h 03m 34s} (current),
                  15.191d {+01h 00m 46s} (1950)
GRB_DEC:         -39.083d {-39d 04' 57"} (J2000),
                 -39.027d {-39d 01' 35"} (current),
                 -39.351d {-39d 21' 03"} (1950)
GRB_DATE:        15372 TJD;   176 DOY;   10/06/25
GRB_TIME:        66748.37 SOD {18:32:28.37} UT
TRIGGER_INDEX:   126
GRB_PHI:         -17.28 [deg]
GRB_THETA:         2.05 [deg]
DELTA_TIME:      -70.00 [sec]
TRIGGER_DUR:     0.256 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     93.24 [sigma]
IMAGE_SIGNIF:    15.27 [sigma]
LC_URL:          sw00425647000msb.lc
SUN_POSTN:        94.46d {+06h 17m 50s}  +23.37d {+23d 22' 27"}
SUN_DIST:         96.23 [deg]   Sun_angle= 5.2 [hr] (West of Sun)
MOON_POSTN:      265.37d {+17h 41m 30s}  -24.75d {-24d 44' 46"}
MOON_DIST:        89.07 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      292.18,-77.80 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      355.62,-41.48 [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 = 230.64,-20.56 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Jun 10 18:36:21 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     425647,   Seg_Num: 0
POINT_RA:         15.769d {+01h 03m 05s} (J2000)
POINT_DEC:       -39.083d {-39d 05' 00"} (J2000)
POINT_ROLL:      64.913d
IMG_START_DATE:  15372 TJD;   176 DOY;   10/06/25
IMG_START_TIME:  66804.71 SOD {18:33:24.71} UT,   56.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.205
N_STARS:         16
X_OFFSET:        645 [pixels]
Y_OFFSET:        633 [pixels]
X_MAX:           1604 [pixels]
Y_MAX:           1592 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw00425647000msufc0056.fits
SUN_POSTN:        94.46d {+06h 17m 50s}  +23.37d {+23d 22' 27"}
SUN_DIST:         96.23 [deg]   Sun_angle= 5.2 [hr] (West of Sun)
MOON_POSTN:      265.37d {+17h 41m 30s}  -24.75d {-24d 44' 45"}
MOON_DIST:        89.06 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      292.19,-77.80 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      355.62,-41.48 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Jun 10 18:36:40 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     425647,   Seg_Num: 0
POINT_RA:         15.769d {+01h 03m 05s} (J2000)
POINT_DEC:       -39.083d {-39d 05' 00"} (J2000)
POINT_ROLL:      64.913d
IMG_START_DATE:  15372 TJD;   176 DOY;   10/06/25
IMG_START_TIME:  66804.71 SOD {18:33:24.71} UT,   56.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.205
N_STARS:         16
X_OFFSET:        645 [pixels]
Y_OFFSET:        633 [pixels]
X_MAX:           1604 [pixels]
Y_MAX:           1592 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw00425647000msufc0056.fits
SUN_POSTN:        94.46d {+06h 17m 50s}  +23.37d {+23d 22' 27"}
SUN_DIST:         96.23 [deg]   Sun_angle= 5.2 [hr] (West of Sun)
MOON_POSTN:      265.38d {+17h 41m 31s}  -24.75d {-24d 44' 45"}
MOON_DIST:        89.06 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      292.19,-77.80 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      355.62,-41.48 [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:     Fri 25 Jun 10 18:38:05 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     425647,   Seg_Num: 0
POINT_RA:         15.769d {+01h 03m 05s} (J2000)
POINT_DEC:       -39.083d {-39d 05' 00"} (J2000)
ROLL:            64.913d
IMG_START_DATE:  15372 TJD;   176 DOY;   10/06/25
IMG_START_TIME:  66804.71 SOD {18:33:24.71} UT,   56.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     299183610
X_OFFSET:        965 [pixels]
Y_OFFSET:        953 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1125
Y_GRB_POS:       1113
BINNING_INDEX:   1
IM_URL:          sw00425647000msuni0062.fits
SUN_POSTN:        94.46d {+06h 17m 50s}  +23.37d {+23d 22' 27"}
SUN_DIST:         96.23 [deg]   Sun_angle= 5.2 [hr] (West of Sun)
MOON_POSTN:      265.39d {+17h 41m 34s}  -24.75d {-24d 44' 42"}
MOON_DIST:        89.05 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      292.19,-77.80 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      355.62,-41.48 [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:     Fri 25 Jun 10 18:38:18 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     425647,   Seg_Num: 0
POINT_RA:         15.769d {+01h 03m 05s} (J2000)
POINT_DEC:       -39.083d {-39d 05' 00"} (J2000)
ROLL:            64.913d
IMG_START_DATE:  15372 TJD;   176 DOY;   10/06/25
IMG_START_TIME:  66804.71 SOD {18:33:24.71} UT,   56.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     299183610
X_OFFSET:        965 [pixels]
Y_OFFSET:        953 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1125
Y_GRB_POS:       1113
BINNING_INDEX:   1
IM_URL:          sw00425647000msuni0062.fits
SUN_POSTN:        94.46d {+06h 17m 51s}  +23.37d {+23d 22' 27"}
SUN_DIST:         96.23 [deg]   Sun_angle= 5.2 [hr] (West of Sun)
MOON_POSTN:      265.39d {+17h 41m 34s}  -24.75d {-24d 44' 42"}
MOON_DIST:        89.05 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      292.19,-77.80 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      355.62,-41.48 [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:     Fri 25 Jun 10 18:36:21 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     425647,   Seg_Num: 0
POINT_RA:         15.769d {+01h 03m 05s} (J2000)
POINT_DEC:       -39.083d {-39d 05' 00"} (J2000)
POINT_ROLL:      64.913d
IMG_START_DATE:  15372 TJD;   176 DOY;   10/06/25
IMG_START_TIME:  66804.71 SOD {18:33:24.71} UT,   56.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.205
N_STARS:         16
X_OFFSET:        645 [pixels]
Y_OFFSET:        633 [pixels]
X_MAX:           1604 [pixels]
Y_MAX:           1592 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw00425647000msufc0056.fits
SUN_POSTN:        94.46d {+06h 17m 50s}  +23.37d {+23d 22' 27"}
SUN_DIST:         96.23 [deg]   Sun_angle= 5.2 [hr] (West of Sun)
MOON_POSTN:      265.37d {+17h 41m 30s}  -24.75d {-24d 44' 45"}
MOON_DIST:        89.06 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      292.19,-77.80 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      355.62,-41.48 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN Circular #10884
S. T. Holland (CRESST/USRA/GSFC), D. N. Burrows (PSU), J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA), W.B Landsman (GSFC), O. M. Littlejohns (U Leicester), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL), A. Rowlinson (U Leicester), T. Sakamoto (NASA/UMBC), B. Sbarufatti (INAF-OAB/IASFPA), M. H. Siegel (PSU), M. Stamatikos (OSU/NASA/GSFC) and R. L. C. Starling (U Leicester) report on behalf of the Swift Team:
At 18:32:28 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 100625A (trigger=425647). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 15.771, -39.083 which is
```
   RA(J2000) = 01h 03m 05s
   Dec(J2000) = -39d 04' 57"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single peak with substructure with a duration of about 0.4 sec. The peak count rate was ~19,000 counts/sec (15-350 keV), at ~0.3 sec after the trigger.
The XRT began observing the field at 18:33:16.7 UT, 48.3 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source located at RA, Dec 15.79489, -39.08833 which is equivalent to:
```
   RA(J2000)  = 01h 03m 10.77s
   Dec(J2000) = -39d 05' 18.0"
```
with an uncertainty of 4.0 arcseconds (radius, 90% containment). This location is 70 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper. We cannot determine whether the source is fading at the present time.
A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 2.15e+20 cm^-2 (Kalberla et al. 2005).
The initial flux in the 2.5 s image was 7.93e-10 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 56 seconds after the BAT trigger. No credible 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 19.6 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 0.01.
Burst Advocate for this burst is S. T. Holland (Stephen.T.Holland 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:     Fri 25 Jun 10 18:43:54 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     425647,   Seg_Num: 0
POINT_RA:         15.768d {+01h 03m 04s} (J2000)
POINT_DEC:       -39.083d {-39d 04' 56"} (J2000)
POINT_ROLL:      64.911d
IMG_START_DATE:  15372 TJD;   176 DOY;   10/06/25
IMG_START_TIME:  67017.68 SOD {18:36:57.68} UT,   269.3 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.543
N_STARS:         16
X_OFFSET:        645 [pixels]
Y_OFFSET:        633 [pixels]
X_MAX:           1604 [pixels]
Y_MAX:           1592 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00425647000msufc0269.fits
SUN_POSTN:        94.46d {+06h 17m 51s}  +23.37d {+23d 22' 26"}
SUN_DIST:         96.23 [deg]   Sun_angle= 5.2 [hr] (West of Sun)
MOON_POSTN:      265.45d {+17h 41m 47s}  -24.74d {-24d 44' 31"}
MOON_DIST:        89.02 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      292.19,-77.80 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      355.62,-41.48 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Jun 10 18:44:15 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     425647,   Seg_Num: 0
POINT_RA:         15.768d {+01h 03m 04s} (J2000)
POINT_DEC:       -39.083d {-39d 04' 56"} (J2000)
POINT_ROLL:      64.911d
IMG_START_DATE:  15372 TJD;   176 DOY;   10/06/25
IMG_START_TIME:  67017.68 SOD {18:36:57.68} UT,   269.3 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.543
N_STARS:         16
X_OFFSET:        645 [pixels]
Y_OFFSET:        633 [pixels]
X_MAX:           1604 [pixels]
Y_MAX:           1592 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00425647000msufc0269.fits
SUN_POSTN:        94.46d {+06h 17m 52s}  +23.37d {+23d 22' 26"}
SUN_DIST:         96.23 [deg]   Sun_angle= 5.2 [hr] (West of Sun)
MOON_POSTN:      265.45d {+17h 41m 48s}  -24.74d {-24d 44' 31"}
MOON_DIST:        89.02 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      292.19,-77.80 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      355.62,-41.48 [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:     Fri 25 Jun 10 18:45:03 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     425647,   Seg_Num: 0
GRB_RA:           15.7956d {+01h 03m 10.94s} (J2000),
                  15.9170d {+01h 03m 40.06s} (current),
                  15.2158d {+01h 00m 51.79s} (1950)
GRB_DEC:         -39.0882d {-39d 05' 17.5"} (J2000),
                 -39.0321d {-39d 01' 55.4"} (current),
                 -39.3565d {-39d 21' 23.2"} (1950)
GRB_ERROR:       2.5 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  15372 TJD;   176 DOY;   10/06/25
IMG_START_TIME:  66813.00 SOD {18:33:33.00} UT,   64.6 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:        94.47d {+06h 17m 52s}  +23.37d {+23d 22' 26"}
SUN_DIST:         96.22 [deg]   Sun_angle= 5.2 [hr] (West of Sun)
MOON_POSTN:      265.46d {+17h 41m 50s}  -24.74d {-24d 44' 29"}
MOON_DIST:        89.03 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      292.09,-77.79 [deg] galactic lon,lat of the burst
ECL_COORDS:      355.64,-41.49 [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:     Fri 25 Jun 10 18:45:30 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     425647,   Seg_Num: 0
POINT_RA:         15.768d {+01h 03m 04s} (J2000)
POINT_DEC:       -39.083d {-39d 04' 56"} (J2000)
ROLL:            64.911d
IMG_START_DATE:  15372 TJD;   176 DOY;   10/06/25
IMG_START_TIME:  67017.68 SOD {18:36:57.68} UT,   269.3 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     299183823
X_OFFSET:        965 [pixels]
Y_OFFSET:        953 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1125
Y_GRB_POS:       1113
BINNING_INDEX:   1
IM_URL:          sw00425647000msuni0275.fits
SUN_POSTN:        94.47d {+06h 17m 52s}  +23.37d {+23d 22' 26"}
SUN_DIST:         96.23 [deg]   Sun_angle= 5.2 [hr] (West of Sun)
MOON_POSTN:      265.46d {+17h 41m 51s}  -24.74d {-24d 44' 29"}
MOON_DIST:        89.01 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      292.19,-77.80 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      355.62,-41.48 [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:     Fri 25 Jun 10 18:45:46 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     425647,   Seg_Num: 0
POINT_RA:         15.768d {+01h 03m 04s} (J2000)
POINT_DEC:       -39.083d {-39d 04' 56"} (J2000)
ROLL:            64.911d
IMG_START_DATE:  15372 TJD;   176 DOY;   10/06/25
IMG_START_TIME:  67017.68 SOD {18:36:57.68} UT,   269.3 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     299183823
X_OFFSET:        965 [pixels]
Y_OFFSET:        953 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1125
Y_GRB_POS:       1113
BINNING_INDEX:   1
IM_URL:          sw00425647000msuni0275.fits
SUN_POSTN:        94.47d {+06h 17m 52s}  +23.37d {+23d 22' 26"}
SUN_DIST:         96.23 [deg]   Sun_angle= 5.2 [hr] (West of Sun)
MOON_POSTN:      265.47d {+17h 41m 52s}  -24.74d {-24d 44' 28"}
MOON_DIST:        89.01 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      292.19,-77.80 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      355.62,-41.48 [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:     Fri 25 Jun 10 18:43:54 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     425647,   Seg_Num: 0
POINT_RA:         15.768d {+01h 03m 04s} (J2000)
POINT_DEC:       -39.083d {-39d 04' 56"} (J2000)
POINT_ROLL:      64.911d
IMG_START_DATE:  15372 TJD;   176 DOY;   10/06/25
IMG_START_TIME:  67017.68 SOD {18:36:57.68} UT,   269.3 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.543
N_STARS:         16
X_OFFSET:        645 [pixels]
Y_OFFSET:        633 [pixels]
X_MAX:           1604 [pixels]
Y_MAX:           1592 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00425647000msufc0269.fits
SUN_POSTN:        94.46d {+06h 17m 51s}  +23.37d {+23d 22' 26"}
SUN_DIST:         96.23 [deg]   Sun_angle= 5.2 [hr] (West of Sun)
MOON_POSTN:      265.45d {+17h 41m 47s}  -24.74d {-24d 44' 31"}
MOON_DIST:        89.02 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      292.19,-77.80 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      355.62,-41.48 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN Circular #10885
D. Suzuki, F. Hayashi, S. Kobara, T. Sako, H.Naito, K. Omori (STE Lab, Nagoya Univ.) on behalf of the MOA Collaboration report:
We searched for an optical afterglow of GRB 100625A (GCN 10884, S. T. Holland et al.) starting from 18:49 UT on 2010 June 25th (17 minutes after the BAT trigger) with the MOA-II 1.8m telescope at Mt.John observatory in New Zealand. In a single image of a 60sec exposure with a wide-band Red filter (center wavelength ~ 750nm and FWHM ~ 250nm), we did not find any object within the error circle of the Swift XRT source position (GCN 10884). A 3 sigma upper limit is set in the I magnitude at 22.77 mag.
This photometry was done by using the DoPhot and calibrated against the USNO-B1.0 catalog stars, and not corrected for the Galactic extinction.
GCN Circular #10886
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team.
Using 646 s of XRT Photon Counting mode data and 1 UVOT images for GRB 100625A, 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 = 15.79574, -39.08842 which is equivalent to:
```
RA (J2000): 01h 03m 10.98s
Dec (J2000): -39d 05' 18.3"
```
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 #10887
A.J. Levan (U. Warwick) and N.R. Tanvir (U. Leicester) report on behalf of a larger collaboration:
"We observed the location of the short-hard GRB 100625A (Holland et al. GCN 10884) using Gemini-South and GMOS under poor conditions beginning at 06:50 UT. A total exposure time of 600s was obtained in the r-band.
Within the refined XRT localisation (Goad et al. GCN 10886) we find a single source with r~23 (photometric calibration preliminary). The location of the source is:
```
RA(J2000): 01:03:10.9 4
DEC(J2000): -39:05:18.7
```
with an error of approximately 0.5" in each axis. We suggest this may be the afterglow of GRB 100625A, however, given the poor seeing (2.5") we cannot distinguish between an afterglow or underlying host galaxy.
Further observations are planned.
We thank the staff of Gemini South, in particular Fredrik Rantakyro, for their assistance with these observations."
GCN Circular #10888
K.L. Page (U. Leicester) and S. T. Holland (CRESST/USRA/GSFC) report on behalf of the Swift-XRT team:
We have analysed 16 ks of XRT data for GRB 100625A (Holland et al. GCN Circ. 10884), from 61 s to 35.4 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Goad et al. (GCN. Circ 10886).
The light curve can be modelled with a power-law decay with a decay index of alpha=1.34 (+0.44, -0.26), with a small flare in the first orbit of data.
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.34 (+0.31, -0.23). The best-fitting absorption column is consistent with the Galactic value of 2.1 x 10^20 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.2 x 10^-11 (3.6 x 10^-11) erg cm^-2 count^-1.
If the light curve continues to decay with a power-law decay index of 1.34, the count rate at T+24 hours will be 1.1 x 10^-4 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.5 x 10^-15 (3.9 x 10^-15) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00425647.
This circular is an official product of the Swift-XRT team.
GCN Circular #10889
H. Naito, T. Sako, D. Suzuki, S. Kobara and K. Omori (Nagoya Univ.) on behalf of the MOA Collaboration, T. Nagayama, M. Kurita (Nagoya Univ.) and N. Oi (The Graduate University for Advanced Studies/NAOJ) on behalf of the IRSF Collabration report:
We searched for a NIR afterglow of the short GRB 100625A (S. T. Holland et al., GCN 10884) starting from 03:07:07 UT on 2010 June 26 with the SIRIUS on the IRSF 1.4m telescope at SAAO in South Africa. In images of a 20 min exposure with J, H and Ks filter, we did not find any object within the error circle of the Swift XRT source position (M. R. Goad et al., GCN 10886) and at the location of the Gemini source (A. J. Levan and N. R. Tanvir, GCN 10887).
A 3 sigma upper limits are the followings.
```
J > 19.37
H > 18.88
K > 18.02
```
This photometry was done by using the DoPhot and calibrated against the 2MASS cataloged stars.
GCN Circular #10890
S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report:
The short hard GRB 100625A (Swift-BAT trigger #425647: Holland et al., GCN 10884) triggered Konus-Wind at T0=66747.799 s UT (18:32:27.799).
The burst light curve consists of two main peaks separated by ~100 ms, with a total duration of the burst of ~350 ms. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB100625_T66747/
As observed by Konus-Wind the burst had a fluence of 0.83(+/-0.15)x10-6 erg/cm2, and a 16-ms peak flux measured from T0 + 0.128s of 8.1(+/-1.5)x10-6 erg/cm2/s (both in the 20 keV - 2 MeV energy range).
The time-integrated spectrum of the burst (from T0 to T0+0.192 s) is well fit in the 20 keV - 2 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep), with alpha = -0.1(-0.5, +0.6), and Ep = 414(-78,+128) keV, chi2 = 18/18 dof.
This spectrum is equally well fit in the same range by the GRB (Band) model, for which: the low-energy photon index alpha = +0.1 (+/-0.6), the high energy photon index beta = -2.6 ( <-1.9 ), the peak energy Ep = 371(-100,+135) keV, chi2 = 17/17 dof.
All the quoted results are preliminary. All the quoted errors are at the 90% confidence level.
GCN Circular #10891
S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), S. T. Holland (CRESST/USRA/GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (OSU/NASA/GSFC), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+500 sec from the recent telemetry downlink, we report further analysis of BAT GRB 100625A (trigger #425647) (Holland, et al., GCN Circ. 10884). The BAT ground-calculated position is RA, Dec = 15.796, -39.091 deg which is
```
   RA(J2000)  =  01h 03m 11.1s 
   Dec(J2000) = -39d 05' 29.3" 
```
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%.
The mask-weighted light curve shows two overlapping peaks starting at ~T-0.1 sec, peaking at ~T+0.1 and T+0.2 sec, and ending at ~T+0.3 sec. There is a weak soft tail out to ~T+30 sec. T90 (15-350 keV) is 0.33 +- 0.03 sec (estimated error including systematics).
The time-averaged spectrum from T-0.1 to T+0.3 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 0.90 +- 0.10. The fluence in the 15-150 keV band is 2.3 +- 0.2 x 10^-07 erg/cm2. The 1-sec peak photon flux measured from T-0.37 sec in the 15-150 keV band is 2.6 +- 0.2 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/425647/BA/
GCN Circular #10892
W. Landsman (NASA/GSFC/Adnet) and S. Holland ((CRESST/USRA/GSFC) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 100625A 56s after the BAT trigger (Holland et al., GCN Circ. 10884). No optical afterglow consistent with the enhanced XRT position (Page et al., GCN Circ. 10888) or the Gemini-South candidate afterglow position (Levan et al. GCN Circ. 10887) 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) and subsequent exposures are:
```
Filter   T_start(s)  T_stop(s)  Exp(s)   Mag
-----------------------------------------------
white     87          206        147 >21.2 (FC)
u        269          519        246 >20.2 (FC)


white     87        11552        785 >22.6
v        598         5951        412 >20.3
b        524        10640       1117 >21.9
u        269         6522        614 >20.5
w1      4725         6362        393 >20.6
m2      4520         6157        393 >20.5
w2      4111        12302       1125 >21.5
```
The values quoted above are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.012 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #10897
E. Berger, R. Chornock, W. Fong (Harvard), W. Krzeminski (LCO), and G. Anglada (Carnegie/DTM) report:
"We observed the location of the short GRB 100625A (GCN 10884) using the PANIC infrared imager on the Magellan/Baade 6.5-m telescope on 2010 June 27.39 UT (38.9 hours after the burst). A total of 1.75 hours were obtained in J-band in good seeing conditions (0.75 arcsec). Within the refined XRT error circle (GCN 10886) we detect a single object, coincident with the optical source detected by Levan et al. with Gemini about 12.3 hours after the burst (GCN 10887). In our combined image the object appears to be mildly extended. Given the continued detection of the object about 27 hours after the initial Gemini detection (with r~23 mag), and its extended nature, we consider this source to be a potential host galaxy."
GCN Circular #10905
N.R. Tanvir (U. Leicester) and A.J. Levan (U. Warwick) report on behalf of a larger collaboration:
We re-observed the location of the short-hard GRB 100625A using GMOS on Gemini-South on 2010-06-28 beginning at 09:21 UT (approximately 63 hours post-burst).
The source we previously identified within the XRT error circle (Levan et al. GCN 10887) is still detected with no obvious fading. We therefore concur with Berger et al. (GCN 10897) that this source, which is marginally extended, is a good candidate to be the host galaxy of the GRB.
We thank the staff of Gemini South, in particular Fredrik Rantakyro, for their assistance with these observations.
GCN Circular #10906
GRB 100625A: GROND confirmation of constant source
A. Updike (Clemson University), P. Afonso and J. Greiner (both MPE Garching) report on behalf of the GROND team:
We observed the field of the short-hard GRB 100625A, discovered by SWIFT(Holland et al., GCN 10884), simultaneously in g'r'i'z'JHK with GROND (Greiner et al.2008, PASP 120, 405) mounted at the 2.2 m MPI/ESO telescope at La Silla Observatory (Chile).
First epoch observations started at 06:13 UT on June 26, 10.7 hours after the GRB trigger, lasting for about 1 hour and done at high air mass. We took a second epoch starting at 09:29 UT on June 27 (~38 hrs after the trigger), lasting also for about 1 hour and done at seeing of ~ 2''.
Within the enhanced XRT-position error circle (Good et al., GCN 10886) we detect a faint object at a position compatible with the Gemini-South candidate afterglow (Levan & Tanvir, GCN 10887).
Based on stacked images with a total integration time of 49.6 min in g'r'i'z' and 40 min for JHK for each epoch, preliminary AB magnitudes (calibrated with GROND zero points) show that within the errors the object is constant between our two epochs.
As suggested by the Magellan observations (Berger et al., GCN 10897) our results also point to the detection of a possible host galaxy.
GCN Circular #10912
P. N. Bhat (UAH) reports on behalf of the Fermi GBM Team:
"At 18:32:28.47 UT on 25 June 2010, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 100625A (trigger 299183550 / 100625773). which was also detected by the SWIFT-BAT(Holland et al. 2008, GCN 10884) The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 125 degrees.
The GBM light curve shows of 2 closely spaced narrow pulses with a duration (T90) of about 0.32 s (50-300 keV). The time-averaged spectrum from T0-0.128 s to T0+0.192 s is well fit by a power law function with an exponential high energy cutoff. The power law index is -0.64 +0.12/-0.11 and the cutoff energy, parameterized as Epeak, is 509.2 +77.5/-61.5 keV
(C-stat value 710 for 609 d.o.f.).
The event fluence (8-1000 keV) in this time interval is (1.32 +/- 0.05)E-06 erg/cm^2. The 0.064-sec peak photon flux measured starting from T0-0.128 s in the 8-1000 keV band is 15.09 +/- 0.59 ph/s/cm^2.
The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN Report 289.1
GCN_Report 289.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_289_1.pdf by S.T. Holland at CRESST/USRA/GSFC titled: "Final report on Swift Observations of GRB 100625A"
1302.3221 from 15 Feb 13
Wen-fai Fong et al.: Demographics of the Galaxies Hosting Short-duration Gamma-Ray Bursts
We present observations of the afterglows and host galaxies of three short-duration gamma-ray bursts (GRBs): 100625A, 101219A and 110112A. We find that GRB 100625A occurred in a z=0.452 early-type galaxy with a stellar mass of 4.6e9 M_Sun and a stellar population age of 0.7 Gyr, and GRB 101219A originated in a star-forming galaxy at z=0.718 with a stellar mass of 1.4e9 M_Sun, a star formation rate of 16 M_Sun yr^-1, and a stellar population age of 50 Myr. We also report the discovery of the optical afterglow of GRB 110112A, which lacks a coincident host galaxy to i>26 mag and we cannot conclusively identify any field galaxy as a possible host. The bursts have inferred circumburst densities of ~1e-4-1 cm^-3, and isotropic-equivalent gamma-ray and kinetic energies of 1e50-1e51 erg. These events highlight the diversity of galaxies that host short GRBs. To quantify this diversity, we use the sample of 36 Swift short GRBs with robust associations to an environment (~1/2 of 68 short bursts detected by Swift to May 2012) and classify them as follows: late-type (50%), early-type (15%), inconclusive (20%), and host-less (lacking a coincident host galaxy to limits of >26 mag; 15%). To find likely ranges for the true late- and early-type fractions, we assign each of the host-less bursts to the late- or early-type category using probabilistic arguments, and consider the scenario that all hosts in the inconclusive category are early-type galaxies to set an upper bound on the early-type fraction. The most likely ranges for the late- and early-type fractions are ~60-80% and ~20-40%, respectively. We find no clear trend between gamma-ray duration and host type, and no change to the fractions when excluding events recently claimed as possible contaminants from the long GRB/collapsar population. Our reported demographics are consistent with a short GRB rate driven by both stellar mass and star formation.

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Jochen Greiner, last update: 15-Feb-2013 [Disclaimer]