Gamma-ray Burst 120401A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 01 Apr 12 05:25:41 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     519043,   Seg_Num: 0
GRB_RA:           58.068d {+03h 52m 16s} (J2000),
                  58.207d {+03h 52m 50s} (current),
                  57.503d {+03h 50m 01s} (1950)
GRB_DEC:         -17.671d {-17d 40' 15"} (J2000),
                 -17.635d {-17d 38' 05"} (current),
                 -17.819d {-17d 49' 09"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       0 [cnts]    Image_Peak=1570 [image_cnts]
TRIGGER_DUR:     64.000 [sec] 
TRIGGER_INDEX:   20000     E_range: 15-50 keV
BKG_INTEN:       0 [cnts]
BKG_TIME:        0.00 SOD {00:00:00.00} UT
BKG_DUR:         0 [sec]
GRB_DATE:        16018 TJD;    92 DOY;   12/04/01
GRB_TIME:        19455.94 SOD {05:24:15.94} UT
GRB_PHI:         141.11 [deg]
GRB_THETA:         1.79 [deg]
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    7.99 [sigma]
MERIT_PARAMS:     +1  +0  +0  +6  +1  -2  +0  +0 -62  +0 
SUN_POSTN:        10.94d {+00h 43m 45s}   +4.70d {+04d 42' 03"}
SUN_DIST:         51.71 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      119.46d {+07h 57m 51s}  +16.54d {+16d 32' 26"}
MOON_DIST:        69.32 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      209.89,-47.38 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       50.95,-36.88 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This is an image trigger.  (The RATE_SIGNIF & BKG_{INTEN, TIME, DUR} are undefined.)  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 119.20,-1.34 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 01 Apr 12 05:26:58 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     519043,   Seg_Num: 0
GRB_RA:           58.0835d {+03h 52m 20.04s} (J2000),
                  58.2220d {+03h 52m 53.29s} (current),
                  57.5182d {+03h 50m 04.36s} (1950)
GRB_DEC:         -17.6349d {-17d 38' 05.6"} (J2000),
                 -17.5989d {-17d 35' 56.1"} (current),
                 -17.7833d {-17d 46' 59.7"} (1950)
GRB_ERROR:       5.4 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.35e-09 [erg/cm2/sec]
GRB_SIGNIF:      7.21 [sigma]
IMG_START_DATE:  16018 TJD;    92 DOY;   12/04/01
IMG_START_TIME:  19574.19 SOD {05:26:14.19} UT,   118.2 [sec] since BAT Trigger Time
TAM[0-3]:        327.67 237.22 261.58 243.67
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:        10.94d {+00h 43m 45s}   +4.70d {+04d 42' 05"}
SUN_DIST:         51.71 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      119.47d {+07h 57m 54s}  +16.54d {+16d 32' 16"}
MOON_DIST:        69.30 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      209.85,-47.35 [deg] galactic lon,lat of the burst
ECL_COORDS:       50.98,-36.85 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 2.33 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 01 Apr 12 05:27:09 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     519043,   Seg_Num: 0
GRB_RA:           58.0835d {+03h 52m 20.0s} (J2000),
                  58.2220d {+03h 52m 53.2s} (current),
                  57.5182d {+03h 50m 04.3s} (1950)
GRB_DEC:         -17.6349d {-17d 38' 05.6"} (J2000),
                 -17.5989d {-17d 35' 56.1"} (current),
                 -17.7833d {-17d 46' 59.7"} (1950)
GRB_ERROR:       5.0 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       52 [cnts]
IMG_START_DATE:  16018 TJD;    92 DOY;   12/04/01
IMG_START_TIME:  19574.19 SOD {05:26:14.19} UT,   118.2 [sec] since BAT Trigger Time
CENTROID_X:      297.97,  raw= 298  [pixels]
CENTROID_Y:      240.82,  raw= 241  [pixels]
ROLL:            291.24 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -134.77
GRB_POS_XRT_Z:   -13.50
IMAGE_URL:       sw00519043000msxps_rw.img
SUN_POSTN:        10.94d {+00h 43m 45s}   +4.70d {+04d 42' 05"}
SUN_DIST:         51.71 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      119.48d {+07h 57m 54s}  +16.54d {+16d 32' 14"}
MOON_DIST:        69.31 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      209.85,-47.35 [deg] galactic lon,lat of the burst
ECL_COORDS:       50.98,-36.85 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 01 Apr 12 05:27:22 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     519043,   Seg_Num: 0
GRB_RA:           58.0835d {+03h 52m 20.0s} (J2000),
                  58.2220d {+03h 52m 53.2s} (current),
                  57.5182d {+03h 50m 04.3s} (1950)
GRB_DEC:         -17.6349d {-17d 38' 05.6"} (J2000),
                 -17.5989d {-17d 35' 56.1"} (current),
                 -17.7833d {-17d 46' 59.7"} (1950)
GRB_ERROR:       5.0 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       52 [cnts]
IMG_START_DATE:  16018 TJD;    92 DOY;   12/04/01
IMG_START_TIME:  19574.19 SOD {05:26:14.19} UT,   118.2 [sec] since BAT Trigger Time
CENTROID_X:      297.97,  raw= 298  [pixels]
CENTROID_Y:      240.82,  raw= 241  [pixels]
ROLL:            291.24 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -134.77
GRB_POS_XRT_Z:   -13.50
IMAGE_URL:       sw00519043000msxps_rw.img
SUN_POSTN:        10.94d {+00h 43m 45s}   +4.70d {+04d 42' 05"}
SUN_DIST:         51.71 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      119.48d {+07h 57m 55s}  +16.54d {+16d 32' 13"}
MOON_DIST:        69.31 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      209.85,-47.35 [deg] galactic lon,lat of the burst
ECL_COORDS:       50.98,-36.85 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 01 Apr 12 05:28:17 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     519043,   Seg_Num: 0
GRB_RA:           58.068d {+03h 52m 16s} (J2000),
                  58.207d {+03h 52m 50s} (current),
                  57.503d {+03h 50m 01s} (1950)
GRB_DEC:         -17.671d {-17d 40' 15"} (J2000),
                 -17.635d {-17d 38' 05"} (current),
                 -17.819d {-17d 49' 09"} (1950)
GRB_DATE:        16018 TJD;    92 DOY;   12/04/01
GRB_TIME:        19455.94 SOD {05:24:15.94} UT
TRIGGER_INDEX:   20000
GRB_PHI:         141.11 [deg]
GRB_THETA:         1.79 [deg]
DELTA_TIME:      0.00 [sec]
TRIGGER_DUR:     64.000 [sec] 
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    7.99 [sigma]
LC_URL:          sw00519043000msb.lc
SUN_POSTN:        10.94d {+00h 43m 45s}   +4.70d {+04d 42' 06"}
SUN_DIST:         51.71 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      119.49d {+07h 57m 57s}  +16.53d {+16d 32' 05"}
MOON_DIST:        69.34 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      209.89,-47.38 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       50.95,-36.88 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Lightcurve.  
COMMENTS:           
COMMENTS:        The next comments were copied from the BAT_POS Notice:  
COMMENTS:        This is an image trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 119.20,-1.34 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 01 Apr 12 05:29:18 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     519043,   Seg_Num: 0
POINT_RA:         58.073d {+03h 52m 17s} (J2000)
POINT_DEC:       -17.671d {-17d 40' 14"} (J2000)
POINT_ROLL:      291.236d
IMG_START_DATE:  16018 TJD;    92 DOY;   12/04/01
IMG_START_TIME:  19583.07 SOD {05:26:23.07} UT,   127.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.056
N_STARS:         25
X_OFFSET:        496 [pixels]
Y_OFFSET:        536 [pixels]
X_MAX:           1455 [pixels]
Y_MAX:           1495 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    8
SL_URL:          sw00519043000msufc0127.fits
SUN_POSTN:        10.94d {+00h 43m 45s}   +4.70d {+04d 42' 07"}
SUN_DIST:         51.71 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      119.50d {+07h 57m 59s}  +16.53d {+16d 31' 57"}
MOON_DIST:        69.35 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      209.89,-47.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       50.95,-36.88 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 01 Apr 12 05:29:45 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     519043,   Seg_Num: 0
POINT_RA:         58.073d {+03h 52m 17s} (J2000)
POINT_DEC:       -17.671d {-17d 40' 14"} (J2000)
POINT_ROLL:      291.236d
IMG_START_DATE:  16018 TJD;    92 DOY;   12/04/01
IMG_START_TIME:  19583.07 SOD {05:26:23.07} UT,   127.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.056
N_STARS:         25
X_OFFSET:        496 [pixels]
Y_OFFSET:        536 [pixels]
X_MAX:           1455 [pixels]
Y_MAX:           1495 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    8
SL_URL:          sw00519043000msufc0127.fits
SUN_POSTN:        10.94d {+00h 43m 45s}   +4.70d {+04d 42' 07"}
SUN_DIST:         51.71 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      119.50d {+07h 58m 00s}  +16.53d {+16d 31' 53"}
MOON_DIST:        69.35 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      209.89,-47.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       50.95,-36.88 [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:     Sun 01 Apr 12 05:31:01 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     519043,   Seg_Num: 0
POINT_RA:         58.073d {+03h 52m 17s} (J2000)
POINT_DEC:       -17.671d {-17d 40' 14"} (J2000)
ROLL:            291.236d
IMG_START_DATE:  16018 TJD;    92 DOY;   12/04/01
IMG_START_TIME:  19583.07 SOD {05:26:23.07} UT,   127.1 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     354950791
X_OFFSET:        947 [pixels]
Y_OFFSET:        1097 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1107
Y_GRB_POS:       1257
BINNING_INDEX:   1
IM_URL:          sw00519043000msuni0136.fits
SUN_POSTN:        10.94d {+00h 43m 45s}   +4.70d {+04d 42' 08"}
SUN_DIST:         51.71 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      119.51d {+07h 58m 03s}  +16.53d {+16d 31' 43"}
MOON_DIST:        69.36 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      209.89,-47.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       50.95,-36.88 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 01 Apr 12 05:31:13 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     519043,   Seg_Num: 0
POINT_RA:         58.073d {+03h 52m 17s} (J2000)
POINT_DEC:       -17.671d {-17d 40' 14"} (J2000)
ROLL:            291.236d
IMG_START_DATE:  16018 TJD;    92 DOY;   12/04/01
IMG_START_TIME:  19583.07 SOD {05:26:23.07} UT,   127.1 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     354950791
X_OFFSET:        947 [pixels]
Y_OFFSET:        1097 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1107
Y_GRB_POS:       1257
BINNING_INDEX:   1
IM_URL:          sw00519043000msuni0136.fits
SUN_POSTN:        10.94d {+00h 43m 45s}   +4.70d {+04d 42' 09"}
SUN_DIST:         51.71 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      119.51d {+07h 58m 03s}  +16.53d {+16d 31' 42"}
MOON_DIST:        69.36 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      209.89,-47.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       50.95,-36.88 [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 #13182
A. P. Beardmore (U Leicester), W. H. Baumgartner (GSFC/UMBC), V. D'Elia (ASDC), A. Maselli (INAF-IASFPA), C. J. Mountford (U Leicester), C. Pagani (U Leicester), K. L. Page (U Leicester), D. M. Palmer (LANL), T. Sakamoto (NASA/UMBC), M. H. Siegel (PSU), R. L. C. Starling (U Leicester) and B.-B. Zhang (PSU) report on behalf of the Swift Team:
At 05:24:15 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 120401A (trigger=519043). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 58.068, -17.671 which is
```
   RA(J2000) = 03h 52m 16s
   Dec(J2000) = -17d 40' 15"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). As is typical for an image trigger, no activity is apparent in the immediately available light curve.
The XRT began observing the field at 05:26:14.1 UT, 118.3 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 58.0835, -17.6349 which is equivalent to:
```
   RA(J2000)  = +03h 52m 20.04s
   Dec(J2000) = -17d 38' 05.6"
```
with an uncertainty of 5.4 arcseconds (radius, 90% containment). This location is 140 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy.
The initial flux in the 2.5 s image was 1.35e-09 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 127 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 0.05.
Burst Advocate for this burst is A. P. Beardmore (apb AT star.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:     Sun 01 Apr 12 05:35:37 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     519043,   Seg_Num: 0
POINT_RA:         58.073d {+03h 52m 18s} (J2000)
POINT_DEC:       -17.671d {-17d 40' 13"} (J2000)
POINT_ROLL:      291.234d
IMG_START_DATE:  16018 TJD;    92 DOY;   12/04/01
IMG_START_TIME:  19742.24 SOD {05:29:02.24} UT,   286.3 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.795
N_STARS:         6
X_OFFSET:        627 [pixels]
Y_OFFSET:        777 [pixels]
X_MAX:           1586 [pixels]
Y_MAX:           1736 [pixels]
DET_THRESH:      8
PHOTO_THRESH:    3
SL_URL:          sw00519043000msufc0286.fits
SUN_POSTN:        10.94d {+00h 43m 46s}   +4.70d {+04d 42' 13"}
SUN_DIST:         51.71 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      119.55d {+07h 58m 13s}  +16.52d {+16d 31' 06"}
MOON_DIST:        69.39 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      209.89,-47.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       50.95,-36.88 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 01 Apr 12 05:35:52 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     519043,   Seg_Num: 0
POINT_RA:         58.073d {+03h 52m 18s} (J2000)
POINT_DEC:       -17.671d {-17d 40' 13"} (J2000)
POINT_ROLL:      291.234d
IMG_START_DATE:  16018 TJD;    92 DOY;   12/04/01
IMG_START_TIME:  19742.24 SOD {05:29:02.24} UT,   286.3 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.795
N_STARS:         6
X_OFFSET:        627 [pixels]
Y_OFFSET:        777 [pixels]
X_MAX:           1586 [pixels]
Y_MAX:           1736 [pixels]
DET_THRESH:      8
PHOTO_THRESH:    3
SL_URL:          sw00519043000msufc0286.fits
SUN_POSTN:        10.94d {+00h 43m 46s}   +4.70d {+04d 42' 13"}
SUN_DIST:         51.71 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      119.56d {+07h 58m 13s}  +16.52d {+16d 31' 04"}
MOON_DIST:        69.39 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      209.89,-47.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       50.95,-36.88 [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:     Sun 01 Apr 12 05:36:57 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     519043,   Seg_Num: 0
POINT_RA:         58.073d {+03h 52m 18s} (J2000)
POINT_DEC:       -17.671d {-17d 40' 13"} (J2000)
ROLL:            291.234d
IMG_START_DATE:  16018 TJD;    92 DOY;   12/04/01
IMG_START_TIME:  19742.24 SOD {05:29:02.24} UT,   286.3 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     354950950
X_OFFSET:        947 [pixels]
Y_OFFSET:        1097 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1107
Y_GRB_POS:       1257
BINNING_INDEX:   1
IM_URL:          sw00519043000msuni0295.fits
SUN_POSTN:        10.94d {+00h 43m 46s}   +4.70d {+04d 42' 14"}
SUN_DIST:         51.71 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      119.57d {+07h 58m 16s}  +16.52d {+16d 30' 55"}
MOON_DIST:        69.40 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      209.89,-47.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       50.95,-36.88 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 01 Apr 12 05:37:15 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     519043,   Seg_Num: 0
POINT_RA:         58.073d {+03h 52m 18s} (J2000)
POINT_DEC:       -17.671d {-17d 40' 13"} (J2000)
ROLL:            291.234d
IMG_START_DATE:  16018 TJD;    92 DOY;   12/04/01
IMG_START_TIME:  19742.24 SOD {05:29:02.24} UT,   286.3 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     354950950
X_OFFSET:        947 [pixels]
Y_OFFSET:        1097 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1107
Y_GRB_POS:       1257
BINNING_INDEX:   1
IM_URL:          sw00519043000msuni0295.fits
SUN_POSTN:        10.94d {+00h 43m 46s}   +4.70d {+04d 42' 14"}
SUN_DIST:         51.71 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      119.57d {+07h 58m 16s}  +16.51d {+16d 30' 53"}
MOON_DIST:        69.40 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      209.89,-47.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       50.95,-36.88 [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:     Sun 01 Apr 12 05:42:53 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     519043,   Seg_Num: 0
POINT_RA:         58.073d {+03h 52m 18s} (J2000)
POINT_DEC:       -17.671d {-17d 40' 13"} (J2000)
POINT_ROLL:      291.234d
IMG_START_DATE:  16018 TJD;    92 DOY;   12/04/01
IMG_START_TIME:  20323.83 SOD {05:38:43.83} UT,   867.9 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.462
N_STARS:         144
X_OFFSET:        387 [pixels]
Y_OFFSET:        537 [pixels]
X_MAX:           1826 [pixels]
Y_MAX:           1976 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw00519043000msufc0867.fits
SUN_POSTN:        10.95d {+00h 43m 47s}   +4.71d {+04d 42' 20"}
SUN_DIST:         51.71 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      119.62d {+07h 58m 29s}  +16.50d {+16d 30' 07"}
MOON_DIST:        69.44 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      209.89,-47.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       50.95,-36.88 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 01 Apr 12 05:43:06 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     519043,   Seg_Num: 0
POINT_RA:         58.073d {+03h 52m 18s} (J2000)
POINT_DEC:       -17.671d {-17d 40' 13"} (J2000)
POINT_ROLL:      291.234d
IMG_START_DATE:  16018 TJD;    92 DOY;   12/04/01
IMG_START_TIME:  20323.83 SOD {05:38:43.83} UT,   867.9 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.462
N_STARS:         144
X_OFFSET:        387 [pixels]
Y_OFFSET:        537 [pixels]
X_MAX:           1826 [pixels]
Y_MAX:           1976 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw00519043000msufc0867.fits
SUN_POSTN:        10.95d {+00h 43m 47s}   +4.71d {+04d 42' 20"}
SUN_DIST:         51.71 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      119.62d {+07h 58m 29s}  +16.50d {+16d 30' 05"}
MOON_DIST:        69.44 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      209.89,-47.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       50.95,-36.88 [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:     Sun 01 Apr 12 05:43:35 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     519043,   Seg_Num: 0
GRB_RA:           58.0820d {+03h 52m 19.68s} (J2000),
                  58.2205d {+03h 52m 52.93s} (current),
                  57.5167d {+03h 50m 04.01s} (1950)
GRB_DEC:         -17.6358d {-17d 38' 08.8"} (J2000),
                 -17.5998d {-17d 35' 59.3"} (current),
                 -17.7842d {-17d 47' 02.9"} (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:  16018 TJD;    92 DOY;   12/04/01
IMG_START_TIME:  20088.00 SOD {05:34:48.00} UT,   632.1 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:        10.95d {+00h 43m 47s}   +4.71d {+04d 42' 21"}
SUN_DIST:         51.70 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      119.63d {+07h 58m 30s}  +16.50d {+16d 30' 02"}
MOON_DIST:        69.42 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      209.85,-47.35 [deg] galactic lon,lat of the burst
ECL_COORDS:       50.97,-36.85 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        This is an Update Notice -- the RA,Dec values herein supersede the previous XRT_POS Notice.  
COMMENTS:        TAM values, flux and significance fields are not valid.  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.  
COMMENTS:        This position was enhanced using UVOT field astrometry.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.58% < P(seren) < 1.1%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 01 Apr 12 05:44:32 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     519043,   Seg_Num: 0
POINT_RA:         58.073d {+03h 52m 18s} (J2000)
POINT_DEC:       -17.671d {-17d 40' 13"} (J2000)
ROLL:            291.234d
IMG_START_DATE:  16018 TJD;    92 DOY;   12/04/01
IMG_START_TIME:  20323.83 SOD {05:38:43.83} UT,   867.9 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     354951531
X_OFFSET:        946 [pixels]
Y_OFFSET:        1096 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1106
Y_GRB_POS:       1256
BINNING_INDEX:   1
IM_URL:          sw00519043000msuni0876.fits
SUN_POSTN:        10.95d {+00h 43m 47s}   +4.71d {+04d 42' 21"}
SUN_DIST:         51.71 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      119.63d {+07h 58m 32s}  +16.50d {+16d 29' 54"}
MOON_DIST:        69.45 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      209.89,-47.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       50.95,-36.88 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 01 Apr 12 05:44:47 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     519043,   Seg_Num: 0
POINT_RA:         58.073d {+03h 52m 18s} (J2000)
POINT_DEC:       -17.671d {-17d 40' 13"} (J2000)
ROLL:            291.234d
IMG_START_DATE:  16018 TJD;    92 DOY;   12/04/01
IMG_START_TIME:  20323.83 SOD {05:38:43.83} UT,   867.9 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     354951531
X_OFFSET:        946 [pixels]
Y_OFFSET:        1096 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1106
Y_GRB_POS:       1256
BINNING_INDEX:   1
IM_URL:          sw00519043000msuni0876.fits
SUN_POSTN:        10.95d {+00h 43m 48s}   +4.71d {+04d 42' 22"}
SUN_DIST:         51.71 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      119.64d {+07h 58m 33s}  +16.50d {+16d 29' 52"}
MOON_DIST:        69.45 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      209.89,-47.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       50.95,-36.88 [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 #13183
P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:
Using promptly downlinked XRT event data for GRB 120401A, we find an enhanced XRT position of the afterglow: RA, Dec: 58.0819, -17.6359 which is equivalent to:
```
   RA (J2000)  = 03 52 19.67
   Dec (J2000) = -17 38 09.2
```
with an uncertainty of 2.1 arcseconds (radius, 90% confidence). Analysis of the promptly available data is online at http://www.swift.ac.uk/sper/519043.
Position enhancement is is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177).
This circular is an official product of the Swift-XRT team.
GCN Circular #13184
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team.
Using 2418 s of XRT Photon Counting mode data and 3 UVOT images for GRB 120401A, 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 = 58.08251, -17.63577 which is equivalent to:
```
RA (J2000): 03h 52m 19.80s
Dec (J2000): -17d 38' 08.8"
```
with an uncertainty of 1.6 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 #13186
D. M. Palmer (LANL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from recent telemetry downlinks, we report further analysis of BAT GRB 120401A (trigger #519043) (Beardmore, et al., GCN Circ. 13182). The BAT ground-calculated position is RA, Dec = 58.057, -17.658 deg, which is
```
   RA(J2000)  =  03h 52m 13.8s 
   Dec(J2000) = -17d 39' 29.6" 
```
with an uncertainty of 2.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%.
The mask-weighted light curve shows the burst was occuring when the location came into the BAT FoV at T-100 sec during a preplanned slew. There was a decline, then a increase around T+0, and the a decline again returning to baseline around T+180 sec. We are not quoting a T90 because we did not observe the burst in its entirety.
The time-averaged spectrum from T-92.97 to T+52.72 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.66 +- 0.23. The fluence in the 15-150 keV band is 9.1 +- 1.4 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-85 sec in the 15-150 keV band is 0.12 +- 0.04 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/519043/BA/
GCN Circular #13187
P.A. Evans (U. Leicester), O.M. Littlejohns (U. Leicester), A. Maselli (INAF-IASFPA), V. Mangano (INAF-IASFPA), A. Melandri (INAF-OAB), J.A. Kennea (PSU), M.C. Stroh (PSU), D.N. Burrows (PSU) and A.P. Beardmore report on behalf of the Swift-XRT team:
We have analysed 10 ks of XRT data for GRB 120401A (Beardmore et al. GCN Circ. 13182), from 124 s to 24.8 ks after the BAT trigger. The data comprise 519 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN. Circ 13183).
The late-time light curve (from T0+5.0 ks) can be modelled with a power-law decay with a decay index of alpha=1.2 (+0.4, -0.3).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.29 (+0.07, -0.06). The best-fitting absorption column is 1.27 (+0.13, -0.12) x 10^21 cm^-2, in excess of the Galactic value of 3.2 x 10^20 cm^-2 (Kalberla et al. 2005). The PC mode spectrum has a photon index of 1.75 (+0.11, -0.10) and a best-fitting absorption column consistent with the Galactic value. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.0 x 10^-11 (4.3 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     0 (+1.5, -0) x 10^20 cm^-2
Galactic foreground: 3.2 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:	     1.75 (+0.11, -0.10)
```
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00519043.
This circular is an official product of the Swift-XRT team.
GCN Circular #13219
V. Sudilovsky, J. Elliott, J. Greiner (all MPE Garching), T. Kruehler (DARK) and A. Rau (also MPE Garching), report on behalf of the GROND team:
We observed the field of GRB120401A (Swift trigger 519043; Beardmore et al., GCN #13182) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG/ESO telescope at La Silla Observatory (Chile).
First observations started at 23:32 UT on 2012-04-01, 18.1 hours after the GRB trigger. For an exposure time of 18.76 min in g'r'i'z' and 15 min in JHK performed at an average seeing of 1".8 and at an average airmass of 2.1, we find a single point source within the 1".6 enhanced Swift-XRT error circle reported by Evans et al. (GCN #13184) at
```
RA (J2000.0)   =  03:52:19.82 =  58.08258
Dec. (J2000.0) = -17:38:08.5  = -17.63569
```
with an uncertainty of 0.3" in each coordinate.
We estimate preliminary magnitudes (all in AB) of
```
g' > 23,
r' = 22.7 +/- 0.2
i' = 21.5 +/- 0.1
z' = 21.0 +/- 0.1
J  = 20.7 +/- 0.2,
H  > 20.7, and
K  > 18.5
```
The SED, constructed from the Galactic foreground extinction (E_(B-V)=0.053 mag, Schlegel et al. 1998) corrected magnitudes of the object gives a photometric redshift of z=4.5 +- 0.5, while intrinsic or host galaxy extinction alone cannot account for the r'-i' colour.
A second observation began at 23:29 UT on 2012-04-02, 1.75 days after the GRB trigger. Due to telescope pointing problems, JHK were the only filters to cover the GRB location. For an exposure time of 38.3 min in JHK at an average seeing of 1".4 and at an average airmass of 2.0, we do not detect the source. With an upper limit of J (AB) > 21.4, it suggests a decay of at least 0.7 mag.
Given magnitudes are calibrated against GROND zeropoints as well as 2MASS field stars.

Back to JG's homepage

Jochen Greiner, last update: 05-Apr-2012 [Disclaimer]