Gamma-ray Burst 160412A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Apr 16 04:24:18 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     682522,   Seg_Num: 0
GRB_RA:           33.107d {+02h 12m 26s} (J2000),
                  33.195d {+02h 12m 47s} (current),
                  32.837d {+02h 11m 21s} (1950)
GRB_DEC:         -67.645d {-67d 38' 42"} (J2000),
                 -67.569d {-67d 34' 09"} (current),
                 -67.879d {-67d 52' 43"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       3931 [cnts]    Image_Peak=164 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   137     E_range: 15-50 keV
BKG_INTEN:       25226 [cnts]
BKG_TIME:        15815.88 SOD {04:23:35.88} UT
BKG_DUR:         8 [sec]
GRB_DATE:        17490 TJD;   103 DOY;   16/04/12
GRB_TIME:        15834.70 SOD {04:23:54.70} UT
GRB_PHI:         151.11 [deg]
GRB_THETA:        25.35 [deg]
SOLN_STATUS:     0x83
RATE_SIGNIF:     11.57 [sigma]
IMAGE_SIGNIF:    6.80 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +1  -3  +0  +0 -22  +0 
SUN_POSTN:        21.00d {+01h 24m 00s}   +8.83d {+08d 49' 45"}
SUN_DIST:         76.90 [deg]   Sun_angle= -0.8 [hr] (East of Sun)
MOON_POSTN:       87.80d {+05h 51m 12s}  +18.22d {+18d 13' 03"}
MOON_DIST:        94.53 [deg]
MOON_ILLUM:      29 [%]
GAL_COORDS:      291.66,-47.67 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      330.91,-68.62 [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 = 123.30,17.18 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Apr 16 04:25:47 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     682522,   Seg_Num: 0
GRB_RA:           33.0482d {+02h 12m 11.56s} (J2000),
                  33.1368d {+02h 12m 32.82s} (current),
                  32.7773d {+02h 11m 06.55s} (1950)
GRB_DEC:         -67.6266d {-67d 37' 35.7"} (J2000),
                 -67.5507d {-67d 33' 02.4"} (current),
                 -67.8603d {-67d 51' 37.1"} (1950)
GRB_ERROR:       4.7 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       9.17e-09 [erg/cm2/sec]
GRB_SIGNIF:      15.49 [sigma]
IMG_START_DATE:  17490 TJD;   103 DOY;   16/04/12
IMG_START_TIME:  15913.53 SOD {04:25:13.53} UT,   78.8 [sec] since BAT Trigger Time
TAM[0-3]:        327.67 237.21 261.59 243.37
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:        21.00d {+01h 24m 00s}   +8.83d {+08d 49' 47"}
SUN_DIST:         76.88 [deg]   Sun_angle= -0.8 [hr] (East of Sun)
MOON_POSTN:       87.82d {+05h 51m 16s}  +18.22d {+18d 13' 04"}
MOON_DIST:        94.54 [deg]
MOON_ILLUM:      29 [%]
GAL_COORDS:      291.68,-47.70 [deg] galactic lon,lat of the burst
ECL_COORDS:      330.93,-68.59 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 1.75 arcmin from the BAT position.  
COMMENTS:        The object found at this position is either a very bright burst or a cosmic ray hit.  
COMMENTS:        Examine the XRT Image to differentiate (CRs are much more compact); see examples at:  
COMMENTS:        http://www.swift.psu.edu/xrt/XRT_Postage_Stamp_Image_Photo_Gallery.htm .

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Apr 16 04:25:56 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     682522,   Seg_Num: 0
GRB_RA:           33.0482d {+02h 12m 11.5s} (J2000),
                  33.1368d {+02h 12m 32.8s} (current),
                  32.7773d {+02h 11m 06.5s} (1950)
GRB_DEC:         -67.6266d {-67d 37' 35.7"} (J2000),
                 -67.5507d {-67d 33' 02.4"} (current),
                 -67.8603d {-67d 51' 37.1"} (1950)
GRB_ERROR:       4.7 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       240 [cnts]
IMG_START_DATE:  17490 TJD;   103 DOY;   16/04/12
IMG_START_TIME:  15913.53 SOD {04:25:13.53} UT,   78.8 [sec] since BAT Trigger Time
CENTROID_X:      271.85,  raw= 272  [pixels]
CENTROID_Y:      315.84,  raw= 316  [pixels]
ROLL:            347.73 [deg]
GAIN:            4
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   42.54
GRB_POS_XRT_Z:   -78.84
IMAGE_URL:       sw00682522000msxps_rw.img
SUN_POSTN:        21.00d {+01h 24m 00s}   +8.83d {+08d 49' 47"}
SUN_DIST:         76.88 [deg]   Sun_angle= -0.8 [hr] (East of Sun)
MOON_POSTN:       87.82d {+05h 51m 16s}  +18.22d {+18d 13' 04"}
MOON_DIST:        94.54 [deg]
MOON_ILLUM:      29 [%]
GAL_COORDS:      291.68,-47.70 [deg] galactic lon,lat of the burst
ECL_COORDS:      330.93,-68.59 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.  
COMMENTS:        The object found at this position is either a very bright burst or a cosmic ray hit.  
COMMENTS:        Examine the XRT Image to differentiate (CRs are much more compact); see examples at:  
COMMENTS:        http://www.swift.psu.edu/xrt/XRT_Postage_Stamp_Image_Photo_Gallery.htm .

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Apr 16 04:26:02 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     682522,   Seg_Num: 0
GRB_RA:           33.0482d {+02h 12m 11.5s} (J2000),
                  33.1368d {+02h 12m 32.8s} (current),
                  32.7773d {+02h 11m 06.5s} (1950)
GRB_DEC:         -67.6266d {-67d 37' 35.7"} (J2000),
                 -67.5507d {-67d 33' 02.4"} (current),
                 -67.8603d {-67d 51' 37.1"} (1950)
GRB_ERROR:       4.7 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       240 [cnts]
IMG_START_DATE:  17490 TJD;   103 DOY;   16/04/12
IMG_START_TIME:  15913.53 SOD {04:25:13.53} UT,   78.8 [sec] since BAT Trigger Time
CENTROID_X:      271.85,  raw= 272  [pixels]
CENTROID_Y:      315.84,  raw= 316  [pixels]
ROLL:            347.73 [deg]
GAIN:            4
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   42.54
GRB_POS_XRT_Z:   -78.84
IMAGE_URL:       sw00682522000msxps_rw.img
SUN_POSTN:        21.00d {+01h 24m 00s}   +8.83d {+08d 49' 47"}
SUN_DIST:         76.88 [deg]   Sun_angle= -0.8 [hr] (East of Sun)
MOON_POSTN:       87.82d {+05h 51m 17s}  +18.22d {+18d 13' 05"}
MOON_DIST:        94.55 [deg]
MOON_ILLUM:      29 [%]
GAL_COORDS:      291.68,-47.70 [deg] galactic lon,lat of the burst
ECL_COORDS:      330.93,-68.59 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.  
COMMENTS:        The object found at this position is either a very bright burst or a cosmic ray hit.  
COMMENTS:        Examine the XRT Image to differentiate (CRs are much more compact); see examples at:  
COMMENTS:        http://www.swift.psu.edu/xrt/XRT_Postage_Stamp_Image_Photo_Gallery.htm .

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Apr 16 04:27:25 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     682522,   Seg_Num: 0
GRB_RA:           33.107d {+02h 12m 26s} (J2000),
                  33.195d {+02h 12m 47s} (current),
                  32.837d {+02h 11m 21s} (1950)
GRB_DEC:         -67.645d {-67d 38' 42"} (J2000),
                 -67.569d {-67d 34' 09"} (current),
                 -67.879d {-67d 52' 43"} (1950)
GRB_DATE:        17490 TJD;   103 DOY;   16/04/12
GRB_TIME:        15834.70 SOD {04:23:54.70} UT
TRIGGER_INDEX:   137
GRB_PHI:         151.11 [deg]
GRB_THETA:        25.35 [deg]
DELTA_TIME:      39.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x83
RATE_SIGNIF:     11.57 [sigma]
IMAGE_SIGNIF:    6.80 [sigma]
LC_URL:          sw00682522000msb.lc
SUN_POSTN:        21.00d {+01h 24m 00s}   +8.83d {+08d 49' 48"}
SUN_DIST:         76.90 [deg]   Sun_angle= -0.8 [hr] (East of Sun)
MOON_POSTN:       87.83d {+05h 51m 20s}  +18.22d {+18d 13' 06"}
MOON_DIST:        94.54 [deg]
MOON_ILLUM:      29 [%]
GAL_COORDS:      291.66,-47.67 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      330.91,-68.62 [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:        Since the IMAGE_SIGNIF is less than 7 sigma, this is a questionable detection.  
COMMENTS:        This trigger occurred at longitude,latitude = 123.30,17.18 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Apr 16 04:30:40 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     682522,   Seg_Num: 0
POINT_RA:         33.091d {+02h 12m 22s} (J2000)
POINT_DEC:       -67.645d {-67d 38' 42"} (J2000)
POINT_ROLL:      347.726d
IMG_START_DATE:  17490 TJD;   103 DOY;   16/04/12
IMG_START_TIME:  15925.21 SOD {04:25:25.21} UT,   90.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        7.376
N_STARS:         17
X_OFFSET:        561 [pixels]
Y_OFFSET:        400 [pixels]
X_MAX:           1520 [pixels]
Y_MAX:           1359 [pixels]
DET_THRESH:      23
PHOTO_THRESH:    14
SL_URL:          sw00682522000msufc0090.fits
SUN_POSTN:        21.00d {+01h 24m 01s}   +8.83d {+08d 49' 51"}
SUN_DIST:         76.90 [deg]   Sun_angle= -0.8 [hr] (East of Sun)
MOON_POSTN:       87.87d {+05h 51m 28s}  +18.22d {+18d 13' 08"}
MOON_DIST:        94.56 [deg]
MOON_ILLUM:      29 [%]
GAL_COORDS:      291.67,-47.67 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      330.90,-68.61 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Apr 16 04:30:58 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     682522,   Seg_Num: 0
POINT_RA:         33.091d {+02h 12m 22s} (J2000)
POINT_DEC:       -67.645d {-67d 38' 42"} (J2000)
POINT_ROLL:      347.726d
IMG_START_DATE:  17490 TJD;   103 DOY;   16/04/12
IMG_START_TIME:  15925.21 SOD {04:25:25.21} UT,   90.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        7.376
N_STARS:         17
X_OFFSET:        561 [pixels]
Y_OFFSET:        400 [pixels]
X_MAX:           1520 [pixels]
Y_MAX:           1359 [pixels]
DET_THRESH:      23
PHOTO_THRESH:    14
SL_URL:          sw00682522000msufc0090.fits
SUN_POSTN:        21.00d {+01h 24m 01s}   +8.83d {+08d 49' 51"}
SUN_DIST:         76.90 [deg]   Sun_angle= -0.8 [hr] (East of Sun)
MOON_POSTN:       87.87d {+05h 51m 29s}  +18.22d {+18d 13' 08"}
MOON_DIST:        94.56 [deg]
MOON_ILLUM:      29 [%]
GAL_COORDS:      291.67,-47.67 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      330.90,-68.61 [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:     Tue 12 Apr 16 04:33:07 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     682522,   Seg_Num: 0
POINT_RA:         33.091d {+02h 12m 22s} (J2000)
POINT_DEC:       -67.645d {-67d 38' 42"} (J2000)
ROLL:            347.726d
IMG_START_DATE:  17490 TJD;   103 DOY;   16/04/12
IMG_START_TIME:  15925.21 SOD {04:25:25.21} UT,   90.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     482127941
X_OFFSET:        881 [pixels]
Y_OFFSET:        720 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1041
Y_GRB_POS:       880
BINNING_INDEX:   1
IM_URL:          sw00682522000msuni0107.fits
SUN_POSTN:        21.00d {+01h 24m 01s}   +8.83d {+08d 49' 53"}
SUN_DIST:         76.90 [deg]   Sun_angle= -0.8 [hr] (East of Sun)
MOON_POSTN:       87.89d {+05h 51m 34s}  +18.22d {+18d 13' 10"}
MOON_DIST:        94.57 [deg]
MOON_ILLUM:      29 [%]
GAL_COORDS:      291.67,-47.67 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      330.90,-68.61 [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:     Tue 12 Apr 16 04:33:19 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     682522,   Seg_Num: 0
POINT_RA:         33.091d {+02h 12m 22s} (J2000)
POINT_DEC:       -67.645d {-67d 38' 42"} (J2000)
ROLL:            347.726d
IMG_START_DATE:  17490 TJD;   103 DOY;   16/04/12
IMG_START_TIME:  15925.21 SOD {04:25:25.21} UT,   90.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     482127941
X_OFFSET:        881 [pixels]
Y_OFFSET:        720 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1041
Y_GRB_POS:       880
BINNING_INDEX:   1
IM_URL:          sw00682522000msuni0107.fits
SUN_POSTN:        21.00d {+01h 24m 01s}   +8.83d {+08d 49' 54"}
SUN_DIST:         76.90 [deg]   Sun_angle= -0.8 [hr] (East of Sun)
MOON_POSTN:       87.89d {+05h 51m 34s}  +18.22d {+18d 13' 10"}
MOON_DIST:        94.57 [deg]
MOON_ILLUM:      29 [%]
GAL_COORDS:      291.67,-47.67 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      330.90,-68.61 [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 Circular #19298
S. L. Gibson (U Leicester), A. Y. Lien (GSFC/UMBC), K. L. Page (U Leicester), D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the Swift Team:
At 04:23:54 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 160412A (trigger=682522). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 33.107, -67.645 which is
```
   RA(J2000) = 02h 12m 26s
   Dec(J2000) = -67d 38' 42"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex peak structure with a duration of about 80 sec. The peak count rate was ~1800 counts/sec (15-350 keV), at ~13 sec after the trigger.
The XRT began observing the field at 04:25:13.5 UT, 78.8 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 33.0482, -67.6266 which is equivalent to:
```
   RA(J2000)  = +02h 12m 11.57s
   Dec(J2000) = -67d 37' 35.8"
```
with an uncertainty of 4.7 arcseconds (radius, 90% containment). This location is 104 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 9.17e-09 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 90 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 0.04.
Burst Advocate for this burst is S. L. Gibson (slg44 AT le.ac.uk). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Apr 16 04:38:18 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     682522,   Seg_Num: 0
POINT_RA:         33.093d {+02h 12m 22s} (J2000)
POINT_DEC:       -67.644d {-67d 38' 37"} (J2000)
POINT_ROLL:      347.723d
IMG_START_DATE:  17490 TJD;   103 DOY;   16/04/12
IMG_START_TIME:  16137.34 SOD {04:28:57.34} UT,   302.6 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        3.028
N_STARS:         13
X_OFFSET:        561 [pixels]
Y_OFFSET:        400 [pixels]
X_MAX:           1520 [pixels]
Y_MAX:           1359 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    8
SL_URL:          sw00682522000msufc0302.fits
SUN_POSTN:        21.01d {+01h 24m 02s}   +8.83d {+08d 49' 58"}
SUN_DIST:         76.90 [deg]   Sun_angle= -0.8 [hr] (East of Sun)
MOON_POSTN:       87.94d {+05h 51m 47s}  +18.22d {+18d 13' 14"}
MOON_DIST:        94.58 [deg]
MOON_ILLUM:      29 [%]
GAL_COORDS:      291.67,-47.68 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      330.90,-68.61 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Apr 16 04:38:39 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     682522,   Seg_Num: 0
POINT_RA:         33.093d {+02h 12m 22s} (J2000)
POINT_DEC:       -67.644d {-67d 38' 37"} (J2000)
POINT_ROLL:      347.723d
IMG_START_DATE:  17490 TJD;   103 DOY;   16/04/12
IMG_START_TIME:  16137.34 SOD {04:28:57.34} UT,   302.6 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        3.028
N_STARS:         13
X_OFFSET:        561 [pixels]
Y_OFFSET:        400 [pixels]
X_MAX:           1520 [pixels]
Y_MAX:           1359 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    8
SL_URL:          sw00682522000msufc0302.fits
SUN_POSTN:        21.01d {+01h 24m 02s}   +8.83d {+08d 49' 58"}
SUN_DIST:         76.90 [deg]   Sun_angle= -0.8 [hr] (East of Sun)
MOON_POSTN:       87.95d {+05h 51m 47s}  +18.22d {+18d 13' 14"}
MOON_DIST:        94.58 [deg]
MOON_ILLUM:      29 [%]
GAL_COORDS:      291.67,-47.68 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      330.90,-68.61 [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:     Tue 12 Apr 16 04:39:39 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     682522,   Seg_Num: 0
POINT_RA:         33.093d {+02h 12m 22s} (J2000)
POINT_DEC:       -67.644d {-67d 38' 37"} (J2000)
ROLL:            347.723d
IMG_START_DATE:  17490 TJD;   103 DOY;   16/04/12
IMG_START_TIME:  16137.34 SOD {04:28:57.34} UT,   302.6 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     482128153
X_OFFSET:        881 [pixels]
Y_OFFSET:        720 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1041
Y_GRB_POS:       880
BINNING_INDEX:   1
IM_URL:          sw00682522000msuni0319.fits
SUN_POSTN:        21.01d {+01h 24m 02s}   +8.83d {+08d 49' 59"}
SUN_DIST:         76.90 [deg]   Sun_angle= -0.8 [hr] (East of Sun)
MOON_POSTN:       87.96d {+05h 51m 50s}  +18.22d {+18d 13' 15"}
MOON_DIST:        94.59 [deg]
MOON_ILLUM:      29 [%]
GAL_COORDS:      291.67,-47.68 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      330.90,-68.61 [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:     Tue 12 Apr 16 04:39:58 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     682522,   Seg_Num: 0
POINT_RA:         33.093d {+02h 12m 22s} (J2000)
POINT_DEC:       -67.644d {-67d 38' 37"} (J2000)
ROLL:            347.723d
IMG_START_DATE:  17490 TJD;   103 DOY;   16/04/12
IMG_START_TIME:  16137.34 SOD {04:28:57.34} UT,   302.6 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     482128153
X_OFFSET:        881 [pixels]
Y_OFFSET:        720 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1041
Y_GRB_POS:       880
BINNING_INDEX:   1
IM_URL:          sw00682522000msuni0319.fits
SUN_POSTN:        21.01d {+01h 24m 02s}   +8.83d {+08d 49' 60"}
SUN_DIST:         76.90 [deg]   Sun_angle= -0.8 [hr] (East of Sun)
MOON_POSTN:       87.96d {+05h 51m 51s}  +18.22d {+18d 13' 15"}
MOON_DIST:        94.59 [deg]
MOON_ILLUM:      29 [%]
GAL_COORDS:      291.67,-47.68 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      330.90,-68.61 [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:     Tue 12 Apr 16 04:41:57 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     682522,   Seg_Num: 0
POINT_RA:         33.093d {+02h 12m 22s} (J2000)
POINT_DEC:       -67.644d {-67d 38' 37"} (J2000)
POINT_ROLL:      347.722d
IMG_START_DATE:  17490 TJD;   103 DOY;   16/04/12
IMG_START_TIME:  16693.13 SOD {04:38:13.13} UT,   858.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        6.533
N_STARS:         94
X_OFFSET:        321 [pixels]
Y_OFFSET:        160 [pixels]
X_MAX:           1760 [pixels]
Y_MAX:           1599 [pixels]
DET_THRESH:      22
PHOTO_THRESH:    13
SL_URL:          sw00682522000msufc0858.fits
SUN_POSTN:        21.01d {+01h 24m 02s}   +8.83d {+08d 50' 01"}
SUN_DIST:         76.90 [deg]   Sun_angle= -0.8 [hr] (East of Sun)
MOON_POSTN:       87.98d {+05h 51m 55s}  +18.22d {+18d 13' 17"}
MOON_DIST:        94.59 [deg]
MOON_ILLUM:      29 [%]
GAL_COORDS:      291.67,-47.67 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      330.90,-68.61 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Apr 16 04:42:26 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     682522,   Seg_Num: 0
POINT_RA:         33.093d {+02h 12m 22s} (J2000)
POINT_DEC:       -67.644d {-67d 38' 37"} (J2000)
POINT_ROLL:      347.722d
IMG_START_DATE:  17490 TJD;   103 DOY;   16/04/12
IMG_START_TIME:  16693.13 SOD {04:38:13.13} UT,   858.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        6.533
N_STARS:         94
X_OFFSET:        321 [pixels]
Y_OFFSET:        160 [pixels]
X_MAX:           1760 [pixels]
Y_MAX:           1599 [pixels]
DET_THRESH:      22
PHOTO_THRESH:    13
SL_URL:          sw00682522000msufc0858.fits
SUN_POSTN:        21.01d {+01h 24m 02s}   +8.83d {+08d 50' 02"}
SUN_DIST:         76.90 [deg]   Sun_angle= -0.8 [hr] (East of Sun)
MOON_POSTN:       87.99d {+05h 51m 57s}  +18.22d {+18d 13' 17"}
MOON_DIST:        94.60 [deg]
MOON_ILLUM:      29 [%]
GAL_COORDS:      291.67,-47.67 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      330.90,-68.61 [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:     Tue 12 Apr 16 04:43:29 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     682522,   Seg_Num: 0
POINT_RA:         33.093d {+02h 12m 22s} (J2000)
POINT_DEC:       -67.644d {-67d 38' 37"} (J2000)
ROLL:            347.722d
IMG_START_DATE:  17490 TJD;   103 DOY;   16/04/12
IMG_START_TIME:  16693.13 SOD {04:38:13.13} UT,   858.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     482128709
X_OFFSET:        880 [pixels]
Y_OFFSET:        719 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1040
Y_GRB_POS:       879
BINNING_INDEX:   1
IM_URL:          sw00682522000msuni0875.fits
SUN_POSTN:        21.01d {+01h 24m 03s}   +8.83d {+08d 50' 03"}
SUN_DIST:         76.90 [deg]   Sun_angle= -0.8 [hr] (East of Sun)
MOON_POSTN:       88.00d {+05h 51m 59s}  +18.22d {+18d 13' 18"}
MOON_DIST:        94.60 [deg]
MOON_ILLUM:      29 [%]
GAL_COORDS:      291.67,-47.67 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      330.90,-68.61 [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:     Tue 12 Apr 16 04:43:44 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     682522,   Seg_Num: 0
POINT_RA:         33.093d {+02h 12m 22s} (J2000)
POINT_DEC:       -67.644d {-67d 38' 37"} (J2000)
ROLL:            347.722d
IMG_START_DATE:  17490 TJD;   103 DOY;   16/04/12
IMG_START_TIME:  16693.13 SOD {04:38:13.13} UT,   858.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     482128709
X_OFFSET:        880 [pixels]
Y_OFFSET:        719 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1040
Y_GRB_POS:       879
BINNING_INDEX:   1
IM_URL:          sw00682522000msuni0875.fits
SUN_POSTN:        21.01d {+01h 24m 03s}   +8.83d {+08d 50' 03"}
SUN_DIST:         76.90 [deg]   Sun_angle= -0.8 [hr] (East of Sun)
MOON_POSTN:       88.00d {+05h 52m 00s}  +18.22d {+18d 13' 18"}
MOON_DIST:        94.60 [deg]
MOON_ILLUM:      29 [%]
GAL_COORDS:      291.67,-47.67 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      330.90,-68.61 [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 #19299
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team.
Using 2983 s of XRT Photon Counting mode data and 4 UVOT images for GRB 160412A, 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 = 33.04586, -67.62664 which is equivalent to:
```
RA (J2000): 02h 12m 11.01s
Dec (J2000): -67d 37' 35.9"
```
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 #19301
T. N. Ukwatta (LANL) S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), S. L. Gibson (U Leicester), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), (i.e. the Swift-BAT team):
Using the data set from T-61 to T+242 sec from the recent telemetry downlink, we report further analysis of BAT GRB 160412A (trigger #682522) (Gibson, et al., GCN Circ. 19298). The BAT ground-calculated position is RA, Dec = 33.074, -67.636 deg, which is
```
   RA(J2000)  =  02h 12m 17.7s 
   Dec(J2000) = -67d 38' 08.8" 
```
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 75%.
The mask-weighted light curves shows several overlapping peaks starting at ~T-10 sec, peaking at ~T+15 sec, and ending at ~T+70 sec. T90 (15-350 keV) is 31.6 +- 4.0 sec (estimated error including systematics).
The time-averaged spectrum from T-3.35 to T+40.18 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.88 +- 0.08. The fluence in the 15-150 keV band is 1.9 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+14.40 sec in the 15-150 keV band is 1.6 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/682522/BA/
GCN Circular #19303
P.A. Evans (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A. Maselli (INAF-IASFPA), L.M. McCauley (PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), J.P. Osborne (U. Leicester) and S.L. Gibson report on behalf of the Swift-XRT team:
We have analysed 6.1 ks of XRT data for GRB 160412A (Gibson et al. GCN Circ. 19298), from 68 s to 30.8 ks after the BAT trigger. The data comprise 267 s in Windowed Timing (WT) mode (the first 9 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Goad et al. (GCN Circ. 19299).
The light curve can be modelled with a series of power-law decays. The initial decay index is alpha=3.14 (+0.20, -0.25). At T+107 s the decay steepens to an alpha of 5.67 (+0.18, -0.19) before breaking again at T+377 s to a final decay with index alpha=0.26 (+/-0.08).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 3.05 (+0.11, -0.10). The best-fitting absorption column is 4.4 (+/-0.3) x 10^21 cm^-2, in excess of the Galactic value of 4.4 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 2.4 (+0.4, -0.3) and a best-fitting absorption column of 2.6 (+1.3, -1.0) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 2.9 x 10^-11 (5.2 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     2.6 (+1.3, -1.0) x 10^21 cm^-2
Galactic foreground: 4.4 x 10^20 cm^-2
Excess significance: 3.4 sigma
Photon index:	     2.4 (+0.4, -0.3)
```
If the light curve continues to decay with a power-law decay index of 0.26, the count rate at T+24 hours will be 0.023 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 6.6 x 10^-13 (1.2 x 10^-12) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00682522.
This circular is an official product of the Swift-XRT team.
GCN Circular #19308
F. E. Marshall (NASA/GSFC) and S. L. Gibson (U. Leicester) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 160412A 90 s after the BAT trigger (Gibson et al., GCN Circ. 19298). No optical afterglow consistent with the enhanced XRT position (Goad et al. GCN Circ. 19299) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC            90          240          147         >20.4
u_FC               303          552          246         >19.1
white               90         1878          431         >21.1
v                  633         2101          175         >19.3
b                  558         2026          156         >19.7
u                  303         2001          362         >19.5
w1                 682         2150          156         >19.8
m2                1063         2125           97         >19.2
w2                 608         2076          175         >19.7
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.04 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #19314
J. Bolmer, T. Schweyer and J. Greiner (all MPE Garching) report on behalf of the GROND Team:
We observed the field of GRB 160412A (Swift trigger 682522; Gibson et al., GCN #19298) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2m MPG telescope at the ESO La Silla Observatory (Chile).
Observations started at 23:11 UT on 2016-04-12, 18.8 h after the GRB trigger. They were performed at an average seeing of 2.5" and at an average airmass of 2.3.
We detect no source within or close to the Swift-XRT error circle reported by Goad et al. (GCN #19299).
Based on 36 min of exposure in g'r'i'z' and 37 min in JHK, at a mid-time of 023:35 UT, we derive the following preliminary upper limits (in AB system):
```
g' > 23.5 mag,
r' > 23.6 mag,
i' > 22.9 mag,
z' > 22.7 mag,
J > 20.2 mag,
H > 19.6 mag, and
K_s > 19.7 mag.
```
Given upper limits are calibrated against GROND zeropoints (g'r'i'z') as well as 2MASS field stars (JHK_s). No correction for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V)=3D0.03 mag in the direction of the burst (Schlafly & Finkbeiner 2011) has been applied.

Back to JG's homepage

Jochen Greiner, last update: 14-Apr-2016 [Disclaimer]