Gamma-ray Burst 060904

(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:     Mon 04 Sep 06 01:03:39 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     227996,   Seg_Num: 0
GRB_RA:          237.743d {+15h 50m 58s} (J2000),
                 237.797d {+15h 51m 11s} (current),
                 237.338d {+15h 49m 21s} (1950)
GRB_DEC:         +44.966d {+44d 57' 57"} (J2000),
                 +44.946d {+44d 56' 46"} (current),
                 +45.115d {+45d 06' 55"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       5218 [cnts]    Image_Peak=210 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   146     E_range: 25-100 keV
BKG_INTEN:       34141 [cnts]
BKG_TIME:        3782.57 SOD {01:03:02.57} UT
BKG_DUR:         8 [sec]
GRB_DATE:        13982 TJD;   247 DOY;   06/09/04
GRB_TIME:        3801.20 SOD {01:03:21.20} UT
GRB_PHI:         132.64 [deg]
GRB_THETA:        13.69 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     12.12 [sigma]
IMAGE_SIGNIF:    7.71 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +2  +1  +0  +0 -27  +1 
SUN_POSTN:       162.82d {+10h 51m 17s}   +7.30d {+07d 17' 49"}
SUN_DIST:         74.24 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      292.08d {+19h 28m 19s}  -26.70d {-26d 42' 12"}
MOON_DIST:        87.04 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:       71.66, 50.21 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      215.35, 62.42 [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 = 156.19,3.99 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 04 Sep 06 01:04:57 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     227996,   Seg_Num: 0
GRB_RA:          237.7288d {+15h 50m 54.9s} (J2000),
                 237.7829d {+15h 51m 07.8s} (current),
                 237.3236d {+15h 49m 17.6s} (1950)
GRB_DEC:         +44.9855d {+44d 59' 07.8"} (J2000),
                 +44.9657d {+44d 57' 56.4"} (current),
                 +45.1350d {+45d 08' 05.9"} (1950)
GRB_ERROR:       5.4 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       49 [cnts]
IMG_START_DATE:  13982 TJD;   247 DOY;   06/09/04
IMG_START_TIME:  3867.16 SOD {01:04:27.16} UT,   66.0 [sec] since BAT Trigger Time
CENTROID_X:      275.16,  raw= 275  [pixels]
CENTROID_Y:      276.47,  raw= 276  [pixels]
ROLL:            264.46 [deg]
GAIN:            1
MODE:            2, Short Image mode
WAVEFORM:        134
EXPO_TIME:       0.10 [sec]
GRB_POS_XRT_Y:   -52.63
GRB_POS_XRT_Z:   -61.60
IMAGE_URL:       sw00227996000msxps_rw.img
SUN_POSTN:       162.82d {+10h 51m 17s}   +7.30d {+07d 17' 48"}
SUN_DIST:         74.23 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      292.09d {+19h 28m 22s}  -26.70d {-26d 42' 03"}
MOON_DIST:        87.06 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:       71.69, 50.22 [deg] galactic lon,lat of the burst
ECL_COORDS:      215.31, 62.43 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 04 Sep 06 01:04:54 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     227996,   Seg_Num: 0
GRB_RA:          237.7288d {+15h 50m 54.9s} (J2000),
                 237.7829d {+15h 51m 07.8s} (current),
                 237.3236d {+15h 49m 17.6s} (1950)
GRB_DEC:         +44.9855d {+44d 59' 07.8"} (J2000),
                 +44.9657d {+44d 57' 56.4"} (current),
                 +45.1350d {+45d 08' 05.9"} (1950)
GRB_ERROR:       5.4 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       2.69e-08 [erg/cm2/sec]
GRB_SIGNIF:      7.00 [sigma]
IMG_START_DATE:  13982 TJD;   247 DOY;   06/09/04
IMG_START_TIME:  3867.16 SOD {01:04:27.16} UT,   66.0 [sec] since BAT Trigger Time
TAM[0-3]:        327.64 237.18 261.33 243.17
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       162.82d {+10h 51m 17s}   +7.30d {+07d 17' 48"}
SUN_DIST:         74.23 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      292.09d {+19h 28m 22s}  -26.70d {-26d 42' 03"}
MOON_DIST:        87.06 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:       71.69, 50.22 [deg] galactic lon,lat of the burst
ECL_COORDS:      215.31, 62.43 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 04 Sep 06 01:04:54 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     227996,   Seg_Num: 0
GRB_RA:          237.7288d {+15h 50m 54.9s} (J2000),
                 237.7829d {+15h 51m 07.8s} (current),
                 237.3236d {+15h 49m 17.6s} (1950)
GRB_DEC:         +44.9855d {+44d 59' 07.8"} (J2000),
                 +44.9657d {+44d 57' 56.4"} (current),
                 +45.1350d {+45d 08' 05.9"} (1950)
GRB_ERROR:       5.4 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       49 [cnts]
IMG_START_DATE:  13982 TJD;   247 DOY;   06/09/04
IMG_START_TIME:  3867.16 SOD {01:04:27.16} UT,   66.0 [sec] since BAT Trigger Time
CENTROID_X:      275.16,  raw= 275  [pixels]
CENTROID_Y:      276.47,  raw= 276  [pixels]
ROLL:            264.46 [deg]
GAIN:            1
MODE:            2, Short Image mode
WAVEFORM:        134
EXPO_TIME:       0.10 [sec]
GRB_POS_XRT_Y:   -52.63
GRB_POS_XRT_Z:   -61.60
IMAGE_URL:       sw00227996000msxps_rw.img
SUN_POSTN:       162.82d {+10h 51m 17s}   +7.30d {+07d 17' 48"}
SUN_DIST:         74.23 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      292.09d {+19h 28m 22s}  -26.70d {-26d 42' 03"}
MOON_DIST:        87.06 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:       71.69, 50.22 [deg] galactic lon,lat of the burst
ECL_COORDS:      215.31, 62.43 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 04 Sep 06 01:07:02 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     227996,   Seg_Num: 0
GRB_RA:          237.743d {+15h 50m 58s} (J2000),
                 237.797d {+15h 51m 11s} (current),
                 237.338d {+15h 49m 21s} (1950)
GRB_DEC:         +44.966d {+44d 57' 57"} (J2000),
                 +44.946d {+44d 56' 46"} (current),
                 +45.115d {+45d 06' 55"} (1950)
GRB_DATE:        13982 TJD;   247 DOY;   06/09/04
GRB_TIME:        3801.20 SOD {01:03:21.20} UT
TRIGGER_INDEX:   146
GRB_PHI:         132.64 [deg]
GRB_THETA:        13.69 [deg]
DELTA_TIME:      58.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     12.12 [sigma]
IMAGE_SIGNIF:    7.71 [sigma]
LC_URL:          sw00227996000msb.lc
SUN_POSTN:       162.82d {+10h 51m 17s}   +7.30d {+07d 17' 46"}
SUN_DIST:         74.23 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      292.11d {+19h 28m 27s}  -26.70d {-26d 41' 49"}
MOON_DIST:        87.05 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:       71.66, 50.21 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      215.35, 62.42 [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 = 156.19,3.99 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 04 Sep 06 01:07:44 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     227996,   Seg_Num: 0
POINT_RA:        237.757d {+15h 51m 02s} (J2000)
POINT_DEC:       +44.972d {+44d 58' 20"} (J2000)
POINT_ROLL:      264.459d
IMG_START_DATE:  13982 TJD;   247 DOY;   06/09/04
IMG_START_TIME:  3876.42 SOD {01:04:36.42} UT,   75.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        4.497
N_STARS:         21
X_OFFSET:        512 [pixels]
Y_OFFSET:        488 [pixels]
X_MAX:           1471 [pixels]
Y_MAX:           1447 [pixels]
DET_THRESH:      18
PHOTO_THRESH:    10
SL_URL:          sw00227996000msufc0075.fits
SUN_POSTN:       162.82d {+10h 51m 17s}   +7.30d {+07d 17' 45"}
SUN_DIST:         74.24 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      292.12d {+19h 28m 29s}  -26.70d {-26d 41' 44"}
MOON_DIST:        87.05 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:       71.66, 50.20 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      215.36, 62.43 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 04 Sep 06 01:08:06 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     227996,   Seg_Num: 0
POINT_RA:        237.757d {+15h 51m 02s} (J2000)
POINT_DEC:       +44.972d {+44d 58' 20"} (J2000)
POINT_ROLL:      264.459d
IMG_START_DATE:  13982 TJD;   247 DOY;   06/09/04
IMG_START_TIME:  3876.42 SOD {01:04:36.42} UT,   75.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        4.497
N_STARS:         21
X_OFFSET:        512 [pixels]
Y_OFFSET:        488 [pixels]
X_MAX:           1471 [pixels]
Y_MAX:           1447 [pixels]
DET_THRESH:      18
PHOTO_THRESH:    10
SL_URL:          sw00227996000msufc0075.fits
SUN_POSTN:       162.82d {+10h 51m 17s}   +7.30d {+07d 17' 45"}
SUN_DIST:         74.24 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      292.13d {+19h 28m 30s}  -26.70d {-26d 41' 42"}
MOON_DIST:        87.05 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:       71.66, 50.20 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      215.36, 62.43 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_srclist.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 04 Sep 06 01:09:36 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     227996,   Seg_Num: 0
POINT_RA:        237.757d {+15h 51m 02s} (J2000)
POINT_DEC:       +44.972d {+44d 58' 20"} (J2000)
ROLL:            264.459d
IMG_START_DATE:  13982 TJD;   247 DOY;   06/09/04
IMG_START_TIME:  3876.42 SOD {01:04:36.42} UT,   75.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     179024677
X_OFFSET:        955 [pixels]
Y_OFFSET:        908 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1115
Y_GRB_POS:       1068
BINNING_INDEX:   1
IM_URL:          sw00227996000msuni0075.fits
SUN_POSTN:       162.82d {+10h 51m 18s}   +7.30d {+07d 17' 43"}
SUN_DIST:         74.24 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      292.14d {+19h 28m 34s}  -26.69d {-26d 41' 32"}
MOON_DIST:        87.06 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:       71.66, 50.20 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      215.36, 62.43 [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:     Mon 04 Sep 06 01:09:54 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     227996,   Seg_Num: 0
POINT_RA:        237.757d {+15h 51m 02s} (J2000)
POINT_DEC:       +44.972d {+44d 58' 20"} (J2000)
ROLL:            264.459d
IMG_START_DATE:  13982 TJD;   247 DOY;   06/09/04
IMG_START_TIME:  3876.42 SOD {01:04:36.42} UT,   75.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     179024677
X_OFFSET:        955 [pixels]
Y_OFFSET:        908 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1115
Y_GRB_POS:       1068
BINNING_INDEX:   1
IM_URL:          sw00227996000msuni0075.fits
SUN_POSTN:       162.82d {+10h 51m 18s}   +7.30d {+07d 17' 43"}
SUN_DIST:         74.24 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      292.15d {+19h 28m 35s}  -26.69d {-26d 41' 30"}
MOON_DIST:        87.06 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:       71.66, 50.20 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      215.36, 62.43 [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_catalog_image.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 04 Sep 06 01:14:03 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     227996,   Seg_Num: 0
POINT_RA:        237.755d {+15h 51m 01s} (J2000)
POINT_DEC:       +44.973d {+44d 58' 21"} (J2000)
POINT_ROLL:      264.456d
IMG_START_DATE:  13982 TJD;   247 DOY;   06/09/04
IMG_START_TIME:  3981.70 SOD {01:06:21.70} UT,   180.5 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        3.219
N_STARS:         80
X_OFFSET:        635 [pixels]
Y_OFFSET:        588 [pixels]
X_MAX:           1594 [pixels]
Y_MAX:           1547 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw00227996000msufc0180.fits
SUN_POSTN:       162.83d {+10h 51m 18s}   +7.29d {+07d 17' 39"}
SUN_DIST:         74.24 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      292.19d {+19h 28m 46s}  -26.68d {-26d 41' 02"}
MOON_DIST:        87.08 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:       71.66, 50.20 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      215.36, 62.43 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 04 Sep 06 01:14:19 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     227996,   Seg_Num: 0
POINT_RA:        237.755d {+15h 51m 01s} (J2000)
POINT_DEC:       +44.973d {+44d 58' 21"} (J2000)
POINT_ROLL:      264.456d
IMG_START_DATE:  13982 TJD;   247 DOY;   06/09/04
IMG_START_TIME:  3981.70 SOD {01:06:21.70} UT,   180.5 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        3.219
N_STARS:         80
X_OFFSET:        635 [pixels]
Y_OFFSET:        588 [pixels]
X_MAX:           1594 [pixels]
Y_MAX:           1547 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw00227996000msufc0180.fits
SUN_POSTN:       162.83d {+10h 51m 18s}   +7.29d {+07d 17' 39"}
SUN_DIST:         74.24 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      292.19d {+19h 28m 46s}  -26.68d {-26d 41' 00"}
MOON_DIST:        87.08 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:       71.66, 50.20 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      215.36, 62.43 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_srclist.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 04 Sep 06 01:15:30 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     227996,   Seg_Num: 0
POINT_RA:        237.755d {+15h 51m 01s} (J2000)
POINT_DEC:       +44.973d {+44d 58' 21"} (J2000)
ROLL:            264.456d
IMG_START_DATE:  13982 TJD;   247 DOY;   06/09/04
IMG_START_TIME:  3981.70 SOD {01:06:21.70} UT,   180.5 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     179024783
X_OFFSET:        955 [pixels]
Y_OFFSET:        908 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1115
Y_GRB_POS:       1068
BINNING_INDEX:   1
IM_URL:          sw00227996000msuni0180.fits
SUN_POSTN:       162.83d {+10h 51m 18s}   +7.29d {+07d 17' 38"}
SUN_DIST:         74.24 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      292.21d {+19h 28m 49s}  -26.68d {-26d 40' 52"}
MOON_DIST:        87.08 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:       71.66, 50.20 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      215.36, 62.43 [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:     Mon 04 Sep 06 01:15:47 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     227996,   Seg_Num: 0
POINT_RA:        237.755d {+15h 51m 01s} (J2000)
POINT_DEC:       +44.973d {+44d 58' 21"} (J2000)
ROLL:            264.456d
IMG_START_DATE:  13982 TJD;   247 DOY;   06/09/04
IMG_START_TIME:  3981.70 SOD {01:06:21.70} UT,   180.5 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     179024783
X_OFFSET:        955 [pixels]
Y_OFFSET:        908 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1115
Y_GRB_POS:       1068
BINNING_INDEX:   1
IM_URL:          sw00227996000msuni0180.fits
SUN_POSTN:       162.83d {+10h 51m 18s}   +7.29d {+07d 17' 38"}
SUN_DIST:         74.24 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      292.21d {+19h 28m 50s}  -26.68d {-26d 40' 51"}
MOON_DIST:        87.08 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:       71.66, 50.20 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      215.36, 62.43 [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_catalog_image.fits.gz file does not exist; skipping the attachment.

GCN Circular #5502
D. Grupe (PSU), S. D. Barthelmy (GSFC), D. N. Burrows (PSU), M. M. Chester (PSU), N. Gehrels (NASA/GSFC), S. T. Holland (GSFC/USRA), S. D. Hunsberger (PSU), J. A. Kennea (PSU), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL), M. Stamatikos (NASA/ORAU) and M. C. Stroh (PSU) report on behalf of the Swift Team:
At 01:03:21 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 060904 (trigger=227996). Swift slewed immediately to the burst. The BAT on-board calculated location is RA,Dec 237.743, +44.966 {15h 50m 58s, +44d 57' 57"} (J2000) with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows 3 little peaks starting out and then a large peak at T+55 sec and a total burst duration of about 85 sec. The peak count rate was ~9000 counts/sec (15-350 keV), at ~55 sec after the trigger.
The XRT began observing the field at 01:04:27 UT, 66 seconds after the BAT trigger. XRT found a bright, fading, uncatalogued X-ray source located at RA(J2000) = 15h 50m 54.9s, Dec(J2000) = +44d 59' 07.8", with an estimated uncertainty of 5.4 arcseconds (90% confidence radius). This location is 79 arcseconds from the BAT on-board position, within the BAT error circle. The initial flux in the 0.1s image was 2.7e-08 erg/cm2/s (0.2-10 keV).
UVOT took a finding chart exposure of 100 seconds with the White (160-650 nm) filter starting 75 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 0.02.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 04 Sep 06 01:24:38 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     227996,   Seg_Num: 0
POINT_RA:        237.755d {+15h 51m 01s} (J2000)
POINT_DEC:       +44.973d {+44d 58' 21"} (J2000)
POINT_ROLL:      264.456d
IMG_START_DATE:  13982 TJD;   247 DOY;   06/09/04
IMG_START_TIME:  4659.22 SOD {01:17:39.22} UT,   858.0 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        1.709
N_STARS:         115
X_OFFSET:        635 [pixels]
Y_OFFSET:        588 [pixels]
X_MAX:           1594 [pixels]
Y_MAX:           1547 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00227996000msufc0858.fits
SUN_POSTN:       162.83d {+10h 51m 20s}   +7.29d {+07d 17' 30"}
SUN_DIST:         74.24 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      292.30d {+19h 29m 13s}  -26.66d {-26d 39' 51"}
MOON_DIST:        87.12 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:       71.66, 50.20 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      215.36, 62.43 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 04 Sep 06 01:24:58 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     227996,   Seg_Num: 0
POINT_RA:        237.755d {+15h 51m 01s} (J2000)
POINT_DEC:       +44.973d {+44d 58' 21"} (J2000)
POINT_ROLL:      264.456d
IMG_START_DATE:  13982 TJD;   247 DOY;   06/09/04
IMG_START_TIME:  4659.22 SOD {01:17:39.22} UT,   858.0 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        1.709
N_STARS:         115
X_OFFSET:        635 [pixels]
Y_OFFSET:        588 [pixels]
X_MAX:           1594 [pixels]
Y_MAX:           1547 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00227996000msufc0858.fits
SUN_POSTN:       162.83d {+10h 51m 20s}   +7.29d {+07d 17' 29"}
SUN_DIST:         74.24 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      292.31d {+19h 29m 14s}  -26.66d {-26d 39' 49"}
MOON_DIST:        87.12 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:       71.66, 50.20 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      215.36, 62.43 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_srclist.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 04 Sep 06 01:25:55 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     227996,   Seg_Num: 0
POINT_RA:        237.755d {+15h 51m 01s} (J2000)
POINT_DEC:       +44.973d {+44d 58' 21"} (J2000)
ROLL:            264.456d
IMG_START_DATE:  13982 TJD;   247 DOY;   06/09/04
IMG_START_TIME:  4659.22 SOD {01:17:39.22} UT,   858.0 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     179025460
X_OFFSET:        954 [pixels]
Y_OFFSET:        907 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1114
Y_GRB_POS:       1067
BINNING_INDEX:   1
IM_URL:          sw00227996000msuni0858.fits
SUN_POSTN:       162.83d {+10h 51m 20s}   +7.29d {+07d 17' 28"}
SUN_DIST:         74.24 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      292.32d {+19h 29m 16s}  -26.66d {-26d 39' 42"}
MOON_DIST:        87.13 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:       71.66, 50.20 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      215.36, 62.43 [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:     Mon 04 Sep 06 01:26:15 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     227996,   Seg_Num: 0
POINT_RA:        237.755d {+15h 51m 01s} (J2000)
POINT_DEC:       +44.973d {+44d 58' 21"} (J2000)
ROLL:            264.456d
IMG_START_DATE:  13982 TJD;   247 DOY;   06/09/04
IMG_START_TIME:  4659.22 SOD {01:17:39.22} UT,   858.0 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     179025460
X_OFFSET:        954 [pixels]
Y_OFFSET:        907 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1114
Y_GRB_POS:       1067
BINNING_INDEX:   1
IM_URL:          sw00227996000msuni0858.fits
SUN_POSTN:       162.83d {+10h 51m 20s}   +7.29d {+07d 17' 28"}
SUN_DIST:         74.24 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      292.32d {+19h 29m 17s}  -26.66d {-26d 39' 40"}
MOON_DIST:        87.13 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:       71.66, 50.20 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      215.36, 62.43 [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:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_image.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 04 Sep 06 01:26:42 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     227996,   Seg_Num: 0
POINT_RA:        237.755d {+15h 51m 01s} (J2000)
POINT_DEC:       +44.973d {+44d 58' 21"} (J2000)
POINT_ROLL:      264.456d
IMG_START_DATE:  13982 TJD;   247 DOY;   06/09/04
IMG_START_TIME:  5067.26 SOD {01:24:27.26} UT,   1266.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.683
N_STARS:         99
X_OFFSET:        635 [pixels]
Y_OFFSET:        588 [pixels]
X_MAX:           1594 [pixels]
Y_MAX:           1547 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00227996000msufc1266.fits
SUN_POSTN:       162.83d {+10h 51m 20s}   +7.29d {+07d 17' 28"}
SUN_DIST:         74.24 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      292.33d {+19h 29m 18s}  -26.66d {-26d 39' 37"}
MOON_DIST:        87.13 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:       71.66, 50.20 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      215.36, 62.43 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 04 Sep 06 01:27:11 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     227996,   Seg_Num: 0
POINT_RA:        237.755d {+15h 51m 01s} (J2000)
POINT_DEC:       +44.973d {+44d 58' 21"} (J2000)
POINT_ROLL:      264.456d
IMG_START_DATE:  13982 TJD;   247 DOY;   06/09/04
IMG_START_TIME:  5067.26 SOD {01:24:27.26} UT,   1266.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.683
N_STARS:         99
X_OFFSET:        635 [pixels]
Y_OFFSET:        588 [pixels]
X_MAX:           1594 [pixels]
Y_MAX:           1547 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00227996000msufc1266.fits
SUN_POSTN:       162.83d {+10h 51m 20s}   +7.29d {+07d 17' 27"}
SUN_DIST:         74.24 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      292.33d {+19h 29m 19s}  -26.66d {-26d 39' 34"}
MOON_DIST:        87.13 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:       71.66, 50.20 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      215.36, 62.43 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_srclist.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 04 Sep 06 01:27:56 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     227996,   Seg_Num: 0
POINT_RA:        237.755d {+15h 51m 01s} (J2000)
POINT_DEC:       +44.973d {+44d 58' 21"} (J2000)
ROLL:            264.456d
IMG_START_DATE:  13982 TJD;   247 DOY;   06/09/04
IMG_START_TIME:  5067.26 SOD {01:24:27.26} UT,   1266.1 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     179025868
X_OFFSET:        954 [pixels]
Y_OFFSET:        907 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1114
Y_GRB_POS:       1067
BINNING_INDEX:   1
IM_URL:          sw00227996000msuni1266.fits
SUN_POSTN:       162.83d {+10h 51m 20s}   +7.29d {+07d 17' 27"}
SUN_DIST:         74.24 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      292.34d {+19h 29m 21s}  -26.66d {-26d 39' 29"}
MOON_DIST:        87.13 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:       71.66, 50.20 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      215.36, 62.43 [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:     Mon 04 Sep 06 01:28:15 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     227996,   Seg_Num: 0
POINT_RA:        237.755d {+15h 51m 01s} (J2000)
POINT_DEC:       +44.973d {+44d 58' 21"} (J2000)
ROLL:            264.456d
IMG_START_DATE:  13982 TJD;   247 DOY;   06/09/04
IMG_START_TIME:  5067.26 SOD {01:24:27.26} UT,   1266.1 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     179025868
X_OFFSET:        954 [pixels]
Y_OFFSET:        907 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1114
Y_GRB_POS:       1067
BINNING_INDEX:   1
IM_URL:          sw00227996000msuni1266.fits
SUN_POSTN:       162.83d {+10h 51m 20s}   +7.29d {+07d 17' 26"}
SUN_DIST:         74.24 [deg]   Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN:      292.34d {+19h 29m 22s}  -26.66d {-26d 39' 27"}
MOON_DIST:        87.13 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:       71.66, 50.20 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      215.36, 62.43 [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:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_image.fits.gz file does not exist; skipping the attachment.

GCN Circular #5503
Richard J. Cool (Arizona), Daniel J. Eisenstein (Arizona), David W. Hogg (NYU), Michael R. Blanton (NYU), David J. Schlegel (LBNL), J. Brinkmann (APO), Donald Q. Lamb (Chicago), Donald P. Schneider (PSU), and Daniel E. Vanden Berk (PSU) report:
The Sloan Digital Sky Survey (SDSS) imaged the field of burst GRB060904 prior to the burst. As these data should be useful as a pre-burst comparison and for calibrating photometry, we are supplying the images and photometry measurements for this GRB field to the community.
Data from the SDSS, including 5 FITS images, 3 JPGS, and 3 files of photometry and astrometry, are being placed at http://mizar.as.arizona.edu/~grb/public/GRB060904
We supply FITS images in each of the 5 SDSS bands of a 8'x8' region centered on the GRB position (ra=237.743 (15:50:58.3), dec=44.9660 (44:57:57.6); Swift-BAT TRIGGER 227996), as well as 3 gri color-composite JPGs (with different stretches). The units in the FITS images are nanomaggies per pixel. A pixel is 0.396 arcsec on a side. A nanomaggie is a flux-density unit equal to 10^-9 of a magnitude 0 source or, to the extent that SDSS is an AB system, 3.631e-6 Jy. The FITS images have WCS astrometric information.
In the file GRB060904_sdss.calstar.dat, we report photometry and astrometry of 309 bright stars (r<20.5) within 15' of the burst location. The magnitudes presented in this file are asinh magnitudes as are standard in the SDSS (Lupton 1999, AJ, 118, 1406). Beware that some of these stars are not well-detected in the u-band; use the errors and object flags to monitor data quality.
In the files GRB060904_sdss.objects_flux.dat and GRB060904_sdss.objects_magnitudes.dat, we report photometry of 451 objects detected within 6' of the GRB position. We have removed saturated objects and objects with model magnitudes fainter than 23.0 in the r-band. The fluxes listed in GRB060904_sdss.objects_flux.dat are in nanomaggies while the magnitudes listed in GRB060904_sdss.objects_magnitudes.dat are asinh magnitudes.
All quantities reported are standard SDSS photometry, meaning that they are very close to AB zeropoints and magnitudes are quoted in asinh magnitudes. Photometric zeropoints are known to about 2% rms. None of the photometry is corrected for dust extinction. The Schlegel, Finkbeiner, and Davis (1998) predictions for this region are A_U=0.089 mag, A_g=0.065 mag, A_r = 0.047 mag, A_i=0.036 mag, and A_z=0.025 mag.
The file GRB060904_sdss.spectro.dat contains a list of the 3 objects with SDSS spectroscopy within 6 arcminutes of the GRB position. In addition to the redshift and 1-sigma error for each object, this file also lists the object spectroscopic classification.
SDSS astrometry is generally better than 0.1 arcsecond per coordinate. Users requiring high precision astrometry should take note that the SDSS astrometric system can differ from other systems such as those used in other notices; we have not checked the offsets in this region.
More detailed information pertaining to our SDSS GRB releases can be found in our initial data release paper (Cool et al. 2006, astro-ph/0601218). See the SDSS DR4 documentation for more details: http://www.sdss.org/dr5.
These data have been reduced using a slightly different pipeline than that used for SDSS public data releases. We cannot guarantee that the values here will exactly match those in the data release in which these data are included. In particular, we expect the photometric calibrations to differ by of order 0.01 mag.
This note may be cited, but please also cite the SDSS data release paper, Adelman-McCarthy et al. (2006, ApJS, 162, 38), when using the data or referring to the technical documentation.
GCN Circular #5506
Klotz, A. (CESR-OMP), Boer M. (OHP), Atteia J.L. (LATT-OMP) report:
We imaged the field of GRB 060904 detected by SWIFT (trigger 227996) with the TAROT robotic telescope (D=25cm) located at the Calern observatory, France.
First image was acquired 26.8s after the GRB trigger (9.4s after the notice). The field elevation decreased from 10 degrees above horizon and weather conditions were excellents. First image was acquired during the prompt phase.
Date of trigger : t0 = 2006-09-04T01:03:21.600
First image is 60.0 exposure trailed. No OT is visible in the XRT error box (Grupe et al. GCNC 5502) t0+26.8s to t0+86.8s : R > 16.0
Second image is 30.0 exposure. No OT is visible: t0+93.7s to t0+123.7s : R > 17.3
We co-added a series of exposures. No OT is visible: t0+93.7s to t0+376.2s : R > 19.5
Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction.
N.B. Galactic coordinates are lon= 71.6566 lat=+50.2105 and the galactic extinction in R band is 0.0 magnitudes estimated from D. Schlegel et al. 1998ApJ...500..525S.
This message may be cited.
GCN Circular #5512
S. B. Cenko and A. Rau (Caltech) report on behalf of a larger collaboration:
We have imaged the error circle of GRB 060904a (Grupe et al; GCN 5502) with the automated Palomar 60-inch telescope. Observations began at 4:57 UT 4 September (3.9 hours after the burst) and consisted of 12 x 180 s images in the Kron R and Sloan i' and z' filters. We find no sources inside the XRT error circle, to a limiting magnitude of R > 22.0 (estimated by comparison with several USNO-B objects in the field).
GCN Circular #5514
Kazuhisa Mitsuda on behalf of Suzaku team
We have just started to observe GRB 060904A (GCN 5502: D. Grupe et al.) at location (RA, Dec)={15h 50m 58s, +44d 57' 57"} (J2000) with the Suzaku narrow field instruments (the XIS and HXD). The observation has started at 10:30 UT, on 4 September (UT), and continue until 05:04 of 5 September, 2006 (UT).
We encourage further follow-up observations with other wavelengths.
GCN Circular #5515
D. Grupe (PSU) reports on behalf of the Swift/XRT team
We have analyzed the first orbit with a total observing time of 2.06 ks of Swift XRT data of GRB 060904A (Grupe et al., GCN 5502).
The X-ray light curve displays the end of a giant flare with a flattening of the light curve at 200s after the burst. The initial decay slope is 3.8+/-0.2 followed by 1.3+/-0.2.
Spectral fits to the Windowed Timing mode data during the flare phase suggest a significant absorption column density in excess of the Galactic value (1.41e20 cm**-2). The spectrum can be fitted by a single power law with a photon index Gamma=1.93+/-0.04 and an absorption column density NH=1.7+/-0.1e21.
Due to the detection of GRB 060904B (Grupe et al., GCN 5505) about about 1.5 hours after the trigger of GRB 060904A, only one orbit has been observed on GRB 060904A and the data were only taken in Windowed Timing mode. Therefore no photon counting mode data exist currently and no improved position can be given yet.
This circular is an official product of the Swift XRT Team.
GCN Circular #5516
H. Krimm (GSFC/USRA), L. Barbier (GSFC), S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMD), E. Fenimore (LANL), N. Gehrels (GSFC), D. Grupe (PSU), D. Hullinger (BYU-Idaho), C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC) on behalf of the Swift-BAT team:
Using the data set from T-110 to T+843 sec from recent telemetry downlinks, we report further analysis of BAT GRB 060904 (trigger #227996) (Grupe, et al., GCN Circ. 5502). The BAT ground-calculated position is (RA,Dec) = 237.730, 44.984 deg {15h 50m 55.3s, 44d 59' 3.7"} (J2000) +- 1.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 94%.
The mask-weighted lightcurve shows the emission starting at a very low level at ~T-70 sec, then increasing slightly at ~T-7 sec for the trigger with several small peaks until the main peak. The main emission peak starts at T+45, peaking at T+56, and ending at ~T+125 sec. T90 (15-350 keV) is 80 +- 2 sec (estimated error including systematics). Note that the spacecraft slewed to the field of view containing the burst approximately 110 seconds before the trigger, so there is no BAT data before this time.
The time-averaged spectrum from T-23.9 to T+108.7 is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.52 +- 0.04. The fluence in the 15-150 keV band is 7.9 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+55.34 sec in the 15-150 keV band is 4.9 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
GCN Circular #5518
S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, and T. Cline on behalf of the Konus-Wind team report:
The most intense part of the long GRB 060904A (Swift-BAT trigger #227996; Grupe et al., GCN 5502; Krimm et al., GCN 5516) triggered Konus-Wind at T0=3853.821 s UT (01:04:13.821).
As observed by Konus-Wind the burst emission started at T-T0 ~-56 s, peaked at T-T0 ~0 s, and ended at T-T0 ~26 s, so the total burst duration is ~80 s. The burst fluence is 1.59(-0.21, +0.40)x10^-5 erg/cm2, and the 256-ms peak flux measured from T0-0.128 s 1.38(-0.33, +0.46)x10^-6 erg/cm2/s (both in the 20 keV - 2 MeV energy range).
The spectrum of the main pulse (from T0 to T0+16.64 s) is well fitted (in the 20 keV - 2 MeV range) by GRBM (Band) model for which: the low-energy photon index is alpha = -1.00(-0.17, +0.23), the high energy photon index beta = -2.57(-1.00, 0.37), the break energy E0 = 163 (-54, +65) keV (chi2 = 40/61 dof). The peak energy Ep = 163 +/- 31 keV.
All the quoted errors are at the 90% confidence level.
GCN Circular #5521
A. Pelangeon & J-L. Atteia (LATT-OMP) report:
We have used the spectral parameters of GRB 060904A provided by Golenetskii et al. (GCNC 5518) to compute the spectral pseudo-redshift** of this burst detected by SWIFT-BAT (trigger #227996: Grupe et al., GCNC 5502; Krimm et al., GCN 5516).
We find a pseudo-redshift pz= 1.84 +- 0.85
We thank V. Pal'shin for providing the fluence of this GRB during the main pulse (from T0 to T0+16.64 s, KONUS time).
** cf. http://www.ast.obs-mip.fr/grb/pz
GCN Circular #5522
K. Aoki, I. Tanaka (Subaru Telescope, NAOJ) and N. Kawai (Tokyo Tech) report on behalf of the Subaru GRB team:
"We began observing the field of GRB 060904A (Grupe et al., GCN 5502) with MOIRCS on the 8.2m Subaru Telescope at ~6 UT (5 hours after the burst).
In the stacked image of the 18 x 120 sec exposure (mid time UT 6:24) in Ks band, we detected an object with 20.2 mag in the XRT error circle, though the object may be extended. In the the J band image of 21 x 120 sec exposure (mid time UT 7:13), we did not detect an object brighter than 21.0 mag in the XRT error circle. The magnitudes were estimated based on the 2 MASS objects in the field."
GCN Circular #5523
S.R. Oates (UCL-MSSL), D. Grupe (PSU) report on behalf of the Swift/UVOT team:
The Swift/UVOT began observing the field of GRB 060904A at 01:04:36 on 2006-09-04, 75 s after the BAT trigger (Grupe et al., GCN 5502). No new source was detected within the XRT error circle in coadded images in any filter down to the following 3-sigma magnitude upper limits:
```
Filter  Tstart   Tstop   Exposure  3-sigma UL
-------------------------------------------------
V        55       1888     1680    20.11

B        658      1984     97      19.85

U        634      1959     117     19.49

UVW1     610      1936     117     19.91

UVM2     586      1911     117     19.95

UVW2     687      2014     128     20.55

White    75       1997     352.2   21.69
------------------------------------------------
```
These upper limits are not corrected for Galactic extinction E(B-V) = 0.018.
GCN Circular #5527
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 the bright GRB 060904A detected by Swift (GCN Circ 5502, D. Rupe et al.), during the main period of emission lasting 80s (GCN Circ 5516, H. Krimm et al.). No evidence for prompt GeV/TeV emission was found. A preliminary analysis, assuming a differential photon spectral index of -2.4, gives an upper limit on E^2dN/dE at 99% confidence of:
E^2dN/dE at 2 TeV < 2.9 * 10^(-7) erg cm^(-2) (No EBL absorption)
TeV photons are attenuated by pair production with infrared photons in intergalactic space. We calculate an upper limit assuming a redshift of 0.5 using the extragalactic infrared background light (EBL) absorption model of Primack et al. 2005 (AIP Conf. Proc. 745, p. 23). We find 99% confidence level upper limits on E^2dN/dE of:
E^2dN/dE at 200 GeV < 5.5 * 10^(-5) erg cm^(-2) (Primack et al. EBL model)
The energies quoted represent the approximate median energy of the events that would be detected assuming a power law spectrum with differential index -2.4 convolved with the absorption model. These upper limits are preliminary and will be refined with further analysis.
GCN Circular #5543
M. Tashiro, K. Abe, K. Onda, Y. Sato, M. Suzuki, Y. Urata (Saitama U.), M. Ohno, T. Takahashi, T. Asano, T. Uehara, Y. Fukazawa (Hiroshima U.), K. Yamaoka, S. Sugita (Aoyama Gakuin U.), T. Enoto, R. Miyawaki, K. Kokubun, K. Makishima (Univ. of Tokyo), K. Nakazawa, T. Takahashi (ISAS/JAXA), M. Suzuki, Y. Terada, T. Tamagawa (RIKEN), S. Hong (Nihon U.), on behalf of the Suzaku WAM team report:
The bright, long burst, GRB 060904A (Swift-BAT trigger #227996; D. Grupe et al., GCN 5502; Krimm et al., GCN 5516), triggered the Suzaku Wideband All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 01:04:09.040 (UT). The three little peaks and following large peak (GCN 5502) are clearly seen in the light curve observed with the WAM. The T90 duration was ~79 seconds. The fluence in 100 - 1000 keV was 8.66(-4.19 +0.39)x10-6 erg/cm2, while the 1-s peak flux was 2.07(-1.12 +0.09) photons/cm2/s in the same energy range.
Preliminary result shows that the time-averaged spectrum is well described with a single power-law model with the energy index of 1.16 (-0.18 0.20).
All the quoted errors are at statistical 90% confidence level, in which systematic errors are not included.
GCN Circular #5547
H. Mito, T. Soyano, (Tokyo Univ.) and Y. Urata (Saitama Univ.) on behalf of EAFON report:
"We have observed the position of X-ray afterglow using Kiso 1.05m Schmited telescope. The observation was started at 10:20 UT September 4, 2006. The combined image from 20 frames taken with 300 sec exposure shows no optical afterglow associated with the X-ray afterglow position brighter than 22.4 (R) mag.
```
  -------------------------------------------
  Start time  Exposure            Limit(SN=3)
  10:20       300 sec x 20 frame  > 22.4
  -------------------------------------------
```
This message may be cited."

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Jochen Greiner, last update: 16-Apr-2007 [Disclaimer]