Gamma-ray Burst 180324A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Mar 18 04:37:25 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     817345,   Seg_Num: 0
GRB_RA:           76.585d {+05h 06m 20s} (J2000),
                  76.969d {+05h 07m 52s} (current),
                  75.533d {+05h 02m 08s} (1950)
GRB_DEC:         +56.725d {+56d 43' 29"} (J2000),
                 +56.748d {+56d 44' 52"} (current),
                 +56.658d {+56d 39' 27"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       3665 [cnts]    Image_Peak=526 [image_cnts]
TRIGGER_DUR:     0.512 [sec] 
TRIGGER_INDEX:   124     E_range: 25-100 keV
BKG_INTEN:       17389 [cnts]
BKG_TIME:        16619.32 SOD {04:36:59.32} UT
BKG_DUR:         8 [sec]
GRB_DATE:        18201 TJD;    83 DOY;   18/03/24
GRB_TIME:        16629.63 SOD {04:37:09.63} UT
GRB_PHI:         121.83 [deg]
GRB_THETA:        18.04 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     73.98 [sigma]
IMAGE_SIGNIF:    18.63 [sigma]
MERIT_PARAMS:     +1  +0  +0  -1  +2  +6  +0  +1 -17  +0 
SUN_POSTN:         3.21d {+00h 12m 50s}   +1.39d {+01d 23' 22"}
SUN_DIST:         80.00 [deg]   Sun_angle= -4.9 [hr] (East of Sun)
MOON_POSTN:       87.33d {+05h 49m 19s}  +19.70d {+19d 42' 17"}
MOON_DIST:        37.84 [deg]
MOON_ILLUM:      45 [%]
GAL_COORDS:      152.85,  9.50 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       81.20, 33.69 [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 = 111.01,9.01 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Mar 18 04:38:23 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     817345,   Seg_Num: 0
POINT_RA:         76.542d {+05h 06m 10s} (J2000)
POINT_DEC:       +56.715d {+56d 42' 54"} (J2000)
IMG_START_DATE:  18201 TJD;    83 DOY;   18/03/24
IMG_START_TIME:  16697.44 SOD {04:38:17.44} UT,   67.8 [sec] since BAT Trigger Time
COUNTS:          1    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        0    Max_iter_allowed= 4
ERROR_CODE:      1
COMMENTS:        SWIFT-XRT Nack Position.  
COMMENTS:        No source found in the image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Mar 18 04:41:00 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     817345,   Seg_Num: 0
GRB_RA:           76.585d {+05h 06m 20s} (J2000),
                  76.969d {+05h 07m 52s} (current),
                  75.533d {+05h 02m 08s} (1950)
GRB_DEC:         +56.725d {+56d 43' 29"} (J2000),
                 +56.748d {+56d 44' 52"} (current),
                 +56.658d {+56d 39' 27"} (1950)
GRB_DATE:        18201 TJD;    83 DOY;   18/03/24
GRB_TIME:        16629.63 SOD {04:37:09.63} UT
TRIGGER_INDEX:   124
GRB_PHI:         121.83 [deg]
GRB_THETA:        18.04 [deg]
DELTA_TIME:      -70.00 [sec]
TRIGGER_DUR:     0.512 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     73.98 [sigma]
IMAGE_SIGNIF:    18.63 [sigma]
LC_URL:          sw00817345000msb.lc
SUN_POSTN:         3.21d {+00h 12m 51s}   +1.39d {+01d 23' 26"}
SUN_DIST:         80.00 [deg]   Sun_angle= -4.9 [hr] (East of Sun)
MOON_POSTN:       87.37d {+05h 49m 28s}  +19.71d {+19d 42' 27"}
MOON_DIST:        37.84 [deg]
MOON_ILLUM:      45 [%]
GAL_COORDS:      152.85,  9.50 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       81.20, 33.69 [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 = 111.01,9.01 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Mar 18 04:42:01 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     817345,   Seg_Num: 0
GRB_RA:           76.5289d {+05h 06m 06.93s} (J2000),
                  76.9129d {+05h 07m 39.09s} (current),
                  75.4775d {+05h 01m 54.58s} (1950)
GRB_DEC:         +56.7132d {+56d 42' 47.5"} (J2000),
                 +56.7365d {+56d 44' 11.4"} (current),
                 +56.6459d {+56d 38' 45.0"} (1950)
GRB_ERROR:       3.9 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  18201 TJD;    83 DOY;   18/03/24
IMG_START_TIME:  16725.00 SOD {04:38:45.00} UT,   95.4 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:         3.21d {+00h 12m 51s}   +1.39d {+01d 23' 27"}
SUN_DIST:         79.97 [deg]   Sun_angle= -4.9 [hr] (East of Sun)
MOON_POSTN:       87.38d {+05h 49m 30s}  +19.71d {+19d 42' 30"}
MOON_DIST:        37.84 [deg]
MOON_ILLUM:      45 [%]
GAL_COORDS:      152.84,  9.47 [deg] galactic lon,lat of the burst
ECL_COORDS:       81.16, 33.69 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
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:        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:     Sat 24 Mar 18 04:43:06 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     817345,   Seg_Num: 0
POINT_RA:         76.542d {+05h 06m 10s} (J2000)
POINT_DEC:       +56.715d {+56d 42' 55"} (J2000)
POINT_ROLL:      256.734d
IMG_START_DATE:  18201 TJD;    83 DOY;   18/03/24
IMG_START_TIME:  16701.32 SOD {04:38:21.32} UT,   71.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        6.568
N_STARS:         35
X_OFFSET:        314 [pixels]
Y_OFFSET:        663 [pixels]
X_MAX:           1273 [pixels]
Y_MAX:           1622 [pixels]
DET_THRESH:      22
PHOTO_THRESH:    13
SL_URL:          sw00817345000msufc0071.fits
SUN_POSTN:         3.21d {+00h 12m 51s}   +1.39d {+01d 23' 28"}
SUN_DIST:         79.98 [deg]   Sun_angle= -4.9 [hr] (East of Sun)
MOON_POSTN:       87.39d {+05h 49m 33s}  +19.71d {+19d 42' 33"}
MOON_DIST:        37.84 [deg]
MOON_ILLUM:      45 [%]
GAL_COORDS:      152.85,  9.48 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       81.17, 33.69 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Mar 18 04:43:23 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     817345,   Seg_Num: 0
POINT_RA:         76.542d {+05h 06m 10s} (J2000)
POINT_DEC:       +56.715d {+56d 42' 55"} (J2000)
POINT_ROLL:      256.734d
IMG_START_DATE:  18201 TJD;    83 DOY;   18/03/24
IMG_START_TIME:  16701.32 SOD {04:38:21.32} UT,   71.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        6.568
N_STARS:         35
X_OFFSET:        314 [pixels]
Y_OFFSET:        663 [pixels]
X_MAX:           1273 [pixels]
Y_MAX:           1622 [pixels]
DET_THRESH:      22
PHOTO_THRESH:    13
SL_URL:          sw00817345000msufc0071.fits
SUN_POSTN:         3.21d {+00h 12m 51s}   +1.39d {+01d 23' 28"}
SUN_DIST:         79.98 [deg]   Sun_angle= -4.9 [hr] (East of Sun)
MOON_POSTN:       87.39d {+05h 49m 34s}  +19.71d {+19d 42' 34"}
MOON_DIST:        37.84 [deg]
MOON_ILLUM:      45 [%]
GAL_COORDS:      152.85,  9.48 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       81.17, 33.69 [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:     Sat 24 Mar 18 04:44:23 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     817345,   Seg_Num: 0
POINT_RA:         76.542d {+05h 06m 10s} (J2000)
POINT_DEC:       +56.715d {+56d 42' 55"} (J2000)
ROLL:            256.734d
IMG_START_DATE:  18201 TJD;    83 DOY;   18/03/24
IMG_START_TIME:  16701.32 SOD {04:38:21.32} UT,   71.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     543559121
X_OFFSET:        633 [pixels]
Y_OFFSET:        982 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       793
Y_GRB_POS:       1142
BINNING_INDEX:   1
IM_URL:          sw00817345000msuni0092.fits
SUN_POSTN:         3.21d {+00h 12m 51s}   +1.39d {+01d 23' 29"}
SUN_DIST:         79.98 [deg]   Sun_angle= -4.9 [hr] (East of Sun)
MOON_POSTN:       87.40d {+05h 49m 36s}  +19.71d {+19d 42' 37"}
MOON_DIST:        37.84 [deg]
MOON_ILLUM:      45 [%]
GAL_COORDS:      152.85,  9.48 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       81.17, 33.69 [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:     Sat 24 Mar 18 04:44:27 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     817345,   Seg_Num: 0
POINT_RA:         76.542d {+05h 06m 10s} (J2000)
POINT_DEC:       +56.715d {+56d 42' 55"} (J2000)
ROLL:            256.734d
IMG_START_DATE:  18201 TJD;    83 DOY;   18/03/24
IMG_START_TIME:  16701.32 SOD {04:38:21.32} UT,   71.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     543559121
X_OFFSET:        633 [pixels]
Y_OFFSET:        982 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       793
Y_GRB_POS:       1142
BINNING_INDEX:   1
IM_URL:          sw00817345000msuni0092.fits
SUN_POSTN:         3.21d {+00h 12m 51s}   +1.39d {+01d 23' 29"}
SUN_DIST:         79.98 [deg]   Sun_angle= -4.9 [hr] (East of Sun)
MOON_POSTN:       87.40d {+05h 49m 36s}  +19.71d {+19d 42' 37"}
MOON_DIST:        37.84 [deg]
MOON_ILLUM:      45 [%]
GAL_COORDS:      152.85,  9.48 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       81.17, 33.69 [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 NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Mar 18 04:51:51 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     817345,   Seg_Num: 0
POINT_RA:         76.538d {+05h 06m 09s} (J2000)
POINT_DEC:       +56.716d {+56d 42' 58"} (J2000)
POINT_ROLL:      256.731d
IMG_START_DATE:  18201 TJD;    83 DOY;   18/03/24
IMG_START_TIME:  16913.52 SOD {04:41:53.52} UT,   283.9 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.699
N_STARS:         34
X_OFFSET:        74 [pixels]
Y_OFFSET:        423 [pixels]
X_MAX:           1513 [pixels]
Y_MAX:           1862 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00817345000msufc0283.fits
SUN_POSTN:         3.22d {+00h 12m 52s}   +1.39d {+01d 23' 36"}
SUN_DIST:         79.97 [deg]   Sun_angle= -4.9 [hr] (East of Sun)
MOON_POSTN:       87.48d {+05h 49m 55s}  +19.72d {+19d 42' 59"}
MOON_DIST:        37.85 [deg]
MOON_ILLUM:      45 [%]
GAL_COORDS:      152.85,  9.48 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       81.17, 33.69 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Mar 18 04:52:13 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     817345,   Seg_Num: 0
POINT_RA:         76.538d {+05h 06m 09s} (J2000)
POINT_DEC:       +56.716d {+56d 42' 58"} (J2000)
POINT_ROLL:      256.731d
IMG_START_DATE:  18201 TJD;    83 DOY;   18/03/24
IMG_START_TIME:  16913.52 SOD {04:41:53.52} UT,   283.9 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.699
N_STARS:         34
X_OFFSET:        74 [pixels]
Y_OFFSET:        423 [pixels]
X_MAX:           1513 [pixels]
Y_MAX:           1862 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00817345000msufc0283.fits
SUN_POSTN:         3.22d {+00h 12m 52s}   +1.39d {+01d 23' 37"}
SUN_DIST:         79.97 [deg]   Sun_angle= -4.9 [hr] (East of Sun)
MOON_POSTN:       87.48d {+05h 49m 56s}  +19.72d {+19d 42' 60"}
MOON_DIST:        37.85 [deg]
MOON_ILLUM:      45 [%]
GAL_COORDS:      152.85,  9.48 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       81.17, 33.69 [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:     Sat 24 Mar 18 04:52:53 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     817345,   Seg_Num: 0
GRB_RA:           76.5276d {+05h 06m 06.62s} (J2000),
                  76.9116d {+05h 07m 38.78s} (current),
                  75.4762d {+05h 01m 54.27s} (1950)
GRB_DEC:         +56.7135d {+56d 42' 48.6"} (J2000),
                 +56.7368d {+56d 44' 12.5"} (current),
                 +56.6462d {+56d 38' 46.1"} (1950)
GRB_ERROR:       2.2 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  18201 TJD;    83 DOY;   18/03/24
IMG_START_TIME:  16725.00 SOD {04:38:45.00} UT,   95.4 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:         3.22d {+00h 12m 52s}   +1.39d {+01d 23' 37"}
SUN_DIST:         79.96 [deg]   Sun_angle= -4.9 [hr] (East of Sun)
MOON_POSTN:       87.49d {+05h 49m 57s}  +19.72d {+19d 43' 01"}
MOON_DIST:        37.85 [deg]
MOON_ILLUM:      45 [%]
GAL_COORDS:      152.84,  9.47 [deg] galactic lon,lat of the burst
ECL_COORDS:       81.16, 33.69 [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:     Sat 24 Mar 18 04:53:14 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     817345,   Seg_Num: 0
POINT_RA:         76.538d {+05h 06m 09s} (J2000)
POINT_DEC:       +56.716d {+56d 42' 58"} (J2000)
ROLL:            256.731d
IMG_START_DATE:  18201 TJD;    83 DOY;   18/03/24
IMG_START_TIME:  16913.52 SOD {04:41:53.52} UT,   283.9 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     543559334
X_OFFSET:        633 [pixels]
Y_OFFSET:        982 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       793
Y_GRB_POS:       1142
BINNING_INDEX:   1
IM_URL:          sw00817345000msuni0304.fits
SUN_POSTN:         3.22d {+00h 12m 52s}   +1.39d {+01d 23' 38"}
SUN_DIST:         79.97 [deg]   Sun_angle= -4.9 [hr] (East of Sun)
MOON_POSTN:       87.49d {+05h 49m 58s}  +19.72d {+19d 43' 03"}
MOON_DIST:        37.85 [deg]
MOON_ILLUM:      45 [%]
GAL_COORDS:      152.85,  9.48 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       81.17, 33.69 [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:     Sat 24 Mar 18 04:53:28 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     817345,   Seg_Num: 0
POINT_RA:         76.538d {+05h 06m 09s} (J2000)
POINT_DEC:       +56.716d {+56d 42' 58"} (J2000)
ROLL:            256.731d
IMG_START_DATE:  18201 TJD;    83 DOY;   18/03/24
IMG_START_TIME:  16913.52 SOD {04:41:53.52} UT,   283.9 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     543559334
X_OFFSET:        633 [pixels]
Y_OFFSET:        982 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       793
Y_GRB_POS:       1142
BINNING_INDEX:   1
IM_URL:          sw00817345000msuni0304.fits
SUN_POSTN:         3.22d {+00h 12m 52s}   +1.39d {+01d 23' 38"}
SUN_DIST:         79.97 [deg]   Sun_angle= -4.9 [hr] (East of Sun)
MOON_POSTN:       87.50d {+05h 49m 59s}  +19.72d {+19d 43' 03"}
MOON_DIST:        37.85 [deg]
MOON_ILLUM:      45 [%]
GAL_COORDS:      152.85,  9.48 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       81.17, 33.69 [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 #22524
E. Sonbas (Adiyaman Univ.), A. D'Ai (INAF-IASFPA), V. D'Elia (ASDC), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL), M. H. Siegel (PSU) and A. Tohuvavohu (PSU) report on behalf of the Neil Gehrels Swift Observatory Team:
At 04:37:09 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 180324A (trigger=817345). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 76.585, +56.725 which is
```
   RA(J2000) = 05h 06m 20s
   Dec(J2000) = +56d 43' 29"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a small precursor about 5 seconds before the main, short, peak for a total duration of about 6 sec. The peak count rate was ~8000 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 04:38:17.4 UT, 67.8 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 76.52896, 56.71298 which is equivalent to:
```
   RA(J2000)  = 05h 06m 06.95s
   Dec(J2000) = +56d 42' 46.7"
```
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 118 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper. We cannot determine whether the source is fading at the present time.
A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (3.81 x 10^21 cm^-2, Willingale et al. 2013), with an excess column of 7.1 (+6.82/-5.48) x 10^21 cm^-2 (90% confidence).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 71 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 none of the XRT error circle. 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 0.90.
Burst Advocate for this burst is E. Sonbas (edasonbas AT yahoo.com). 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:     Sat 24 Mar 18 04:58:27 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     817345,   Seg_Num: 0
POINT_RA:         76.538d {+05h 06m 09s} (J2000)
POINT_DEC:       +56.716d {+56d 42' 58"} (J2000)
POINT_ROLL:      256.731d
IMG_START_DATE:  18201 TJD;    83 DOY;   18/03/24
IMG_START_TIME:  17493.10 SOD {04:51:33.10} UT,   863.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.317
N_STARS:         176
X_OFFSET:        74 [pixels]
Y_OFFSET:        423 [pixels]
X_MAX:           1513 [pixels]
Y_MAX:           1862 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw00817345000msufc0863.fits
SUN_POSTN:         3.22d {+00h 12m 53s}   +1.40d {+01d 23' 43"}
SUN_DIST:         79.97 [deg]   Sun_angle= -4.9 [hr] (East of Sun)
MOON_POSTN:       87.55d {+05h 50m 11s}  +19.72d {+19d 43' 18"}
MOON_DIST:        37.85 [deg]
MOON_ILLUM:      45 [%]
GAL_COORDS:      152.85,  9.48 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       81.17, 33.69 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Mar 18 04:58:48 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     817345,   Seg_Num: 0
POINT_RA:         76.538d {+05h 06m 09s} (J2000)
POINT_DEC:       +56.716d {+56d 42' 58"} (J2000)
POINT_ROLL:      256.731d
IMG_START_DATE:  18201 TJD;    83 DOY;   18/03/24
IMG_START_TIME:  17493.10 SOD {04:51:33.10} UT,   863.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.317
N_STARS:         176
X_OFFSET:        74 [pixels]
Y_OFFSET:        423 [pixels]
X_MAX:           1513 [pixels]
Y_MAX:           1862 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw00817345000msufc0863.fits
SUN_POSTN:         3.22d {+00h 12m 53s}   +1.40d {+01d 23' 43"}
SUN_DIST:         79.97 [deg]   Sun_angle= -4.9 [hr] (East of Sun)
MOON_POSTN:       87.55d {+05h 50m 12s}  +19.72d {+19d 43' 19"}
MOON_DIST:        37.85 [deg]
MOON_ILLUM:      45 [%]
GAL_COORDS:      152.85,  9.48 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       81.17, 33.69 [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:     Sat 24 Mar 18 05:00:08 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     817345,   Seg_Num: 0
POINT_RA:         76.538d {+05h 06m 09s} (J2000)
POINT_DEC:       +56.716d {+56d 42' 58"} (J2000)
ROLL:            256.731d
IMG_START_DATE:  18201 TJD;    83 DOY;   18/03/24
IMG_START_TIME:  17493.10 SOD {04:51:33.10} UT,   863.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     543559913
X_OFFSET:        633 [pixels]
Y_OFFSET:        982 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       793
Y_GRB_POS:       1142
BINNING_INDEX:   1
IM_URL:          sw00817345000msuni0884.fits
SUN_POSTN:         3.22d {+00h 12m 53s}   +1.40d {+01d 23' 45"}
SUN_DIST:         79.96 [deg]   Sun_angle= -4.9 [hr] (East of Sun)
MOON_POSTN:       87.56d {+05h 50m 16s}  +19.72d {+19d 43' 22"}
MOON_DIST:        37.85 [deg]
MOON_ILLUM:      45 [%]
GAL_COORDS:      152.85,  9.48 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       81.17, 33.69 [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:     Sat 24 Mar 18 05:00:15 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     817345,   Seg_Num: 0
POINT_RA:         76.538d {+05h 06m 09s} (J2000)
POINT_DEC:       +56.716d {+56d 42' 58"} (J2000)
ROLL:            256.731d
IMG_START_DATE:  18201 TJD;    83 DOY;   18/03/24
IMG_START_TIME:  17493.10 SOD {04:51:33.10} UT,   863.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     543559913
X_OFFSET:        633 [pixels]
Y_OFFSET:        982 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       793
Y_GRB_POS:       1142
BINNING_INDEX:   1
IM_URL:          sw00817345000msuni0884.fits
SUN_POSTN:         3.22d {+00h 12m 53s}   +1.40d {+01d 23' 45"}
SUN_DIST:         79.96 [deg]   Sun_angle= -4.9 [hr] (East of Sun)
MOON_POSTN:       87.57d {+05h 50m 16s}  +19.72d {+19d 43' 23"}
MOON_DIST:        37.85 [deg]
MOON_ILLUM:      45 [%]
GAL_COORDS:      152.85,  9.48 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       81.17, 33.69 [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 #22525
P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:
Using promptly downlinked XRT event data for GRB 180324A, we find an enhanced XRT position of the afterglow: RA, Dec: 76.5270, 56.7137 which is equivalent to:
```
   RA (J2000)  = 05 06 06.49
   Dec (J2000) = +56 42 49.2
```
with an uncertainty of 2.0 arcseconds (radius, 90% confidence). Analysis of the promptly available data is online at http://www.swift.ac.uk/sper/817345.
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 #22526
The GRB will run for a few orbits.
At the 08:46 UT Malindi pass we will upload a 1ks observation of ASASSN-18gb.
The following targets in the PPST were lost due to the AT (merit 76) AT observed: 2018-083-09:46:00 - 2018-083-10:04:00 for 1140 secs
```
Merit  TargID Seg Name                           Lost(s) Remain(s)
72      34934 114 OJ 287                           1080         0
72      10556 14  SN2018pv                           60      2040
```
GCN Circular #22527
WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on behalf of the KAIT GRB team:
The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, responded to Swift GRB 180324A (Sonbas et al., GCN 22524) starting at 04:54:12 UT, ~17 minutes after the burst, and lasted ~10 minutes before it reached the physical limit of the telescope. Observations were performed with an automatic sequence in the clear (roughly R), and I filters, and the exposure time was 20 s per image. We do not detect any optical afterglow candidate within the enhanced XRT position error circle (Evans et al., GCN 22525). The typical limiting magnitude of our single clear image is about 19.0 mag calibrated to the APASS catalog.
GCN Circular #22528
FROM: Nat Butler at Az State U
Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jes=FAs Gonz=E1lez (UNAM), Carlos Rom=E1n-Z=FA=F1iga (UNAM), Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki Toy (UMD) report:
We observed the field of GRB 180324A (Sonbas, et al., GCN 22524) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astron=F3mico Nacional on Sierra San Pedro M=E1rtir from 2018/03 24.19 to 2018/03 24.23 UTC (2.4 minutes to 0.92 hours after the BAT trigger), obtaining a total of 0.66 hours exposure in the r and i bands.
We detect a weak source within the Swift-XRT error circle (Evans, et al., GCN 22525) in our first 80 s exposure, i-band image only. In comparison with the USNO-B1 catalog, we find i=3D20.15+/-0.37.
The source is not on the frame in the subsequent image and is not detected in the next possible frame 3.5 minutes later. In our full 0.66 hour exposure time, the source is not detected with the following upper limits (3-sigma):
```
  r > 22.08
  i > 22.04
```
These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. If the detection in the first frame is due to the afterglow, then the afterglow faded rapidly.
We thank the staff of the Observatorio Astron=F3mico Nacional in San Pedro M=E1rtir.
GCN Circular #22529
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team.
Using 2334 s of XRT Photon Counting mode data and 1 UVOT images for GRB 180324A, 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 = 76.52652, +56.71430 which is equivalent to:
```
RA (J2000): 05h 06m 6.37s
Dec (J2000): +56d 42' 51.5"
```
with an uncertainty of 1.7 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 #22530
J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), D.N. Burrows (PSU), A. Tohuvavohu (PSU), S. J. LaPorte (PSU), A.P. Beardmore (U. Leicester) and E. Sonbas report on behalf of the Swift-XRT team:
We have analysed 7.1 ks of XRT data for GRB 180324A (Sonbas et al. GCN Circ. 22524), from 80 s to 13.9 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Goad et al. (GCN Circ. 22525).
The late-time light curve (from T0+5.7 ks) can be modelled with a power-law decay with a decay index of alpha=1.07 (+/-0.16).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.36 (+0.13, -0.12). The best-fitting absorption column is 9.0 (+1.6, -1.4) x 10^21 cm^-2, in excess of the Galactic value of 3.8 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 6.7 x 10^-11 (8.7 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     9.0 (+1.6, -1.4) x 10^21 cm^-2
Galactic foreground: 3.8 x 10^21 cm^-2
Excess significance: 5.9 sigma
Photon index:	     1.36 (+0.13, -0.12)
```
If the light curve continues to decay with a power-law decay index of 1.07, the count rate at T+24 hours will be 0.032 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.2 x 10^-12 (2.8 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/00817345.
This circular is an official product of the Swift-XRT team.
GCN Circular #22531
GRB 180324A: Swift/UVOT Upper Limits
S. J. Laporte (PSU) and E. Sonbas (Adiyaman Univ.) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 180324A 72 s after the BAT trigger (Sonbas et al., GCN Circ. 22524). No optical afterglow consistent with the XRT position (Goad et al. GCN Circ. 22529) or RATIR position (Butler et al. GCN Circ. 22528) 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            72          221          147         >19.8
u_FC               284          534          246         >19.3
white               72        12383         1552         >21.3
v                  614        13894         1172         >19.5
b                  539         8158          549         >20.9
u                  284         7992          814         >20.3
w1                 664         7787          471         >20.2
w2                6970        13290         1082         >21.5
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.90 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #22533
H. A. Krimm (NSF/USRA), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), J. P. Norris (BSU), D. M. Palmer (LANL), T. Sakamoto (AGU), E. Sonbas (Adiyaman Univ.), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 180324A (trigger #817345) (Sonbas et al., GCN Circ. 22524). The BAT ground-calculated position is RA, Dec = 76.581, 56.744 deg which is
```
  RA(J2000)  =  05h 06m 19.4s
  Dec(J2000) = +56d 44' 36.8"
```
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 78%.
The mask-weighted light curve shows a small precursor at ~T-5 s, followed by the main pulse that starts at ~T-0.2, peaks at ~T+0.3 s, and ends at ~T+1 s. There is also some weak emission that lasts till ~T+4 s. T90 (15-350 keV) is 7.2 +- 1.3 sec (estimated error including systematics).
The lag analysis for the main pulse finds a lag of 48 +- 18 ms for the 100-350 keV to 25-100 keV band. This value is consistent with that of a long GRB. In addition, no extended emission is found after ~T+4 s.
The time-averaged spectrum from T-5.4 to T+3.7 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.45 +- 0.14. The fluence in the 15-150 keV band is 5.6 +- 0.5 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-0.13 sec in the 15-150 keV band is 4.4 +- 0.3 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/817345/BA/
GCN Circular #22547
D. Frederiks, S. Golenetskii, R.Aptekar, M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline, on behalf of the Konus-Wind team, report:
GRB 180324A (Swift-BAT trigger 817345: Sonbas et al., GCN 22524; Krimm et al., GCN 22533) triggered Konus-Wind at T0=3D16629.939 s UT (04:37:09.939)
The burst light curve shows a weak pulse, which started at ~T0-0.4 s and peaked at ~T0 s. The total duration of the burst is ~0.7 s. The emission is seen up to ~0.5 MeV.
As observed by Konus-Wind, the burst had a fluence of (7.4 =B1 2.1)x10^-7 erg/cm2 and a 64-ms peak energy flux, measured from T0, of (1.8 =B1 0.5)x10^-6 erg/cm2 (both in the 20 keV - 10 MeV energy range).
The burst spectrum (measured from T0 to T0+0.256 s) is best fit in the 20 keV - 15 MeV range by a cutoff power-law (CPL) function with the following model parameters: the photon index alpha =3D -0.56(-0.71,+1.16), and the peak energy Ep =3D 154(-38,+77) keV, chi2 =3D 22/19 dof. Fitting this spectrum with the GRB (Band) function yields the same alpha and Ep, and an upper limit on beta of ~-2.2
The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB180324_T16629/
All the quoted errors are estimated at the 90% confidence level. All the presented results are preliminary.

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Jochen Greiner, last update: 26-Mar-2018 [Disclaimer]