Gamma-ray Burst 150323A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

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Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 23 Mar 15 02:50:30 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     635887,   Seg_Num: 0
GRB_RA:          128.191d {+08h 32m 46s} (J2000),
                 128.454d {+08h 33m 49s} (current),
                 127.327d {+08h 29m 18s} (1950)
GRB_DEC:         +45.434d {+45d 26' 03"} (J2000),
                 +45.382d {+45d 22' 54"} (current),
                 +45.605d {+45d 36' 17"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       0 [cnts]    Image_Peak=1334 [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:        17104 TJD;    82 DOY;   15/03/23
GRB_TIME:        10154.65 SOD {02:49:14.65} UT
GRB_PHI:         -139.78 [deg]
GRB_THETA:        42.14 [deg]
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    10.18 [sigma]
MERIT_PARAMS:     +1  +0  +0  +6  +1  +0  +0  +0 +40  +0 
SUN_POSTN:         1.98d {+00h 07m 55s}   +0.86d {+00d 51' 30"}
SUN_DIST:        114.00 [deg]   Sun_angle= -8.4 [hr] (East of Sun)
MOON_POSTN:       38.29d {+02h 33m 10s}  +12.34d {+12d 20' 34"}
MOON_DIST:        81.36 [deg]
MOON_ILLUM:      11 [%]
GAL_COORDS:      174.84, 36.30 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      118.79, 25.74 [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 = 314.13,20.43 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 23 Mar 15 02:52:08 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     635887,   Seg_Num: 0
GRB_RA:          128.1817d {+08h 32m 43.60s} (J2000),
                 128.4442d {+08h 33m 46.61s} (current),
                 127.3168d {+08h 29m 16.02s} (1950)
GRB_DEC:         +45.4644d {+45d 27' 51.8"} (J2000),
                 +45.4119d {+45d 24' 42.7"} (current),
                 +45.6348d {+45d 38' 05.4"} (1950)
GRB_ERROR:       5.4 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       3.25e-08 [erg/cm2/sec]
GRB_SIGNIF:      7.21 [sigma]
IMG_START_DATE:  17104 TJD;    82 DOY;   15/03/23
IMG_START_TIME:  10301.20 SOD {02:51:41.20} UT,   146.6 [sec] since BAT Trigger Time
TAM[0-3]:        327.65 237.22 261.52 243.73
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:         1.98d {+00h 07m 56s}   +0.86d {+00d 51' 32"}
SUN_DIST:        113.98 [deg]   Sun_angle= -8.4 [hr] (East of Sun)
MOON_POSTN:       38.31d {+02h 33m 13s}  +12.35d {+12d 20' 48"}
MOON_DIST:        81.34 [deg]
MOON_ILLUM:      11 [%]
GAL_COORDS:      174.80, 36.30 [deg] galactic lon,lat of the burst
ECL_COORDS:      118.78, 25.77 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 1.85 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 23 Mar 15 02:52:19 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     635887,   Seg_Num: 0
GRB_RA:          128.1817d {+08h 32m 43.6s} (J2000),
                 128.4442d {+08h 33m 46.6s} (current),
                 127.3168d {+08h 29m 16.0s} (1950)
GRB_DEC:         +45.4644d {+45d 27' 51.8"} (J2000),
                 +45.4119d {+45d 24' 42.7"} (current),
                 +45.6348d {+45d 38' 05.4"} (1950)
GRB_ERROR:       5.0 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       52 [cnts]
IMG_START_DATE:  17104 TJD;    82 DOY;   15/03/23
IMG_START_TIME:  10301.20 SOD {02:51:41.20} UT,   146.6 [sec] since BAT Trigger Time
CENTROID_X:      261.42,  raw= 261  [pixels]
CENTROID_Y:      270.65,  raw= 271  [pixels]
ROLL:            298.14 [deg]
GAIN:            1
MODE:            2, Short Image mode
WAVEFORM:        134
EXPO_TIME:       0.10 [sec]
GRB_POS_XRT_Y:   -63.99
GRB_POS_XRT_Z:   -103.43
IMAGE_URL:       sw00635887000msxps_rw.img
SUN_POSTN:         1.98d {+00h 07m 56s}   +0.86d {+00d 51' 32"}
SUN_DIST:        113.98 [deg]   Sun_angle= -8.4 [hr] (East of Sun)
MOON_POSTN:       38.31d {+02h 33m 14s}  +12.35d {+12d 20' 50"}
MOON_DIST:        81.34 [deg]
MOON_ILLUM:      11 [%]
GAL_COORDS:      174.80, 36.30 [deg] galactic lon,lat of the burst
ECL_COORDS:      118.78, 25.77 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 23 Mar 15 02:52:25 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     635887,   Seg_Num: 0
GRB_RA:          128.1817d {+08h 32m 43.6s} (J2000),
                 128.4442d {+08h 33m 46.6s} (current),
                 127.3168d {+08h 29m 16.0s} (1950)
GRB_DEC:         +45.4644d {+45d 27' 51.8"} (J2000),
                 +45.4119d {+45d 24' 42.7"} (current),
                 +45.6348d {+45d 38' 05.4"} (1950)
GRB_ERROR:       5.0 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       52 [cnts]
IMG_START_DATE:  17104 TJD;    82 DOY;   15/03/23
IMG_START_TIME:  10301.20 SOD {02:51:41.20} UT,   146.6 [sec] since BAT Trigger Time
CENTROID_X:      261.42,  raw= 261  [pixels]
CENTROID_Y:      270.65,  raw= 271  [pixels]
ROLL:            298.14 [deg]
GAIN:            1
MODE:            2, Short Image mode
WAVEFORM:        134
EXPO_TIME:       0.10 [sec]
GRB_POS_XRT_Y:   -63.99
GRB_POS_XRT_Z:   -103.43
IMAGE_URL:       sw00635887000msxps_rw.img
SUN_POSTN:         1.98d {+00h 07m 56s}   +0.86d {+00d 51' 32"}
SUN_DIST:        113.98 [deg]   Sun_angle= -8.4 [hr] (East of Sun)
MOON_POSTN:       38.31d {+02h 33m 14s}  +12.35d {+12d 20' 51"}
MOON_DIST:        81.33 [deg]
MOON_ILLUM:      11 [%]
GAL_COORDS:      174.80, 36.30 [deg] galactic lon,lat of the burst
ECL_COORDS:      118.78, 25.77 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 23 Mar 15 02:53:09 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     635887,   Seg_Num: 0
GRB_RA:          128.191d {+08h 32m 46s} (J2000),
                 128.454d {+08h 33m 49s} (current),
                 127.327d {+08h 29m 18s} (1950)
GRB_DEC:         +45.434d {+45d 26' 03"} (J2000),
                 +45.382d {+45d 22' 54"} (current),
                 +45.605d {+45d 36' 17"} (1950)
GRB_DATE:        17104 TJD;    82 DOY;   15/03/23
GRB_TIME:        10154.65 SOD {02:49:14.65} UT
TRIGGER_INDEX:   20000
GRB_PHI:         -139.78 [deg]
GRB_THETA:        42.14 [deg]
DELTA_TIME:      0.00 [sec]
TRIGGER_DUR:     64.000 [sec] 
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    10.18 [sigma]
LC_URL:          sw00635887000msb.lc
SUN_POSTN:         1.98d {+00h 07m 56s}   +0.86d {+00d 51' 33"}
SUN_DIST:        114.00 [deg]   Sun_angle= -8.4 [hr] (East of Sun)
MOON_POSTN:       38.32d {+02h 33m 16s}  +12.35d {+12d 20' 57"}
MOON_DIST:        81.34 [deg]
MOON_ILLUM:      11 [%]
GAL_COORDS:      174.84, 36.30 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      118.79, 25.74 [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 = 314.13,20.43 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 23 Mar 15 02:54:43 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     635887,   Seg_Num: 0
POINT_RA:        128.203d {+08h 32m 49s} (J2000)
POINT_DEC:       +45.435d {+45d 26' 06"} (J2000)
POINT_ROLL:      298.133d
IMG_START_DATE:  17104 TJD;    82 DOY;   15/03/23
IMG_START_TIME:  10310.69 SOD {02:51:50.69} UT,   156.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.110
N_STARS:         31
X_OFFSET:        512 [pixels]
Y_OFFSET:        488 [pixels]
X_MAX:           1471 [pixels]
Y_MAX:           1447 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00635887000msufc0156.fits
SUN_POSTN:         1.98d {+00h 07m 56s}   +0.86d {+00d 51' 35"}
SUN_DIST:        114.01 [deg]   Sun_angle= -8.4 [hr] (East of Sun)
MOON_POSTN:       38.33d {+02h 33m 20s}  +12.35d {+12d 21' 10"}
MOON_DIST:        81.33 [deg]
MOON_ILLUM:      11 [%]
GAL_COORDS:      174.84, 36.31 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      118.80, 25.74 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 23 Mar 15 02:55:00 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     635887,   Seg_Num: 0
POINT_RA:        128.203d {+08h 32m 49s} (J2000)
POINT_DEC:       +45.435d {+45d 26' 06"} (J2000)
POINT_ROLL:      298.133d
IMG_START_DATE:  17104 TJD;    82 DOY;   15/03/23
IMG_START_TIME:  10310.69 SOD {02:51:50.69} UT,   156.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.110
N_STARS:         31
X_OFFSET:        512 [pixels]
Y_OFFSET:        488 [pixels]
X_MAX:           1471 [pixels]
Y_MAX:           1447 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00635887000msufc0156.fits
SUN_POSTN:         1.98d {+00h 07m 56s}   +0.86d {+00d 51' 35"}
SUN_DIST:        114.01 [deg]   Sun_angle= -8.4 [hr] (East of Sun)
MOON_POSTN:       38.33d {+02h 33m 20s}  +12.35d {+12d 21' 12"}
MOON_DIST:        81.33 [deg]
MOON_ILLUM:      11 [%]
GAL_COORDS:      174.84, 36.31 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      118.80, 25.74 [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:     Mon 23 Mar 15 02:56:08 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     635887,   Seg_Num: 0
POINT_RA:        128.203d {+08h 32m 49s} (J2000)
POINT_DEC:       +45.435d {+45d 26' 06"} (J2000)
ROLL:            298.133d
IMG_START_DATE:  17104 TJD;    82 DOY;   15/03/23
IMG_START_TIME:  10310.69 SOD {02:51:50.69} UT,   156.0 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     448771924
X_OFFSET:        1041 [pixels]
Y_OFFSET:        887 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1201
Y_GRB_POS:       1047
BINNING_INDEX:   1
IM_URL:          sw00635887000msuni0170.fits
SUN_POSTN:         1.98d {+00h 07m 56s}   +0.86d {+00d 51' 36"}
SUN_DIST:        114.01 [deg]   Sun_angle= -8.4 [hr] (East of Sun)
MOON_POSTN:       38.35d {+02h 33m 23s}  +12.36d {+12d 21' 22"}
MOON_DIST:        81.32 [deg]
MOON_ILLUM:      11 [%]
GAL_COORDS:      174.84, 36.31 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      118.80, 25.74 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 23 Mar 15 02:56:37 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     635887,   Seg_Num: 0
POINT_RA:        128.203d {+08h 32m 49s} (J2000)
POINT_DEC:       +45.435d {+45d 26' 06"} (J2000)
ROLL:            298.133d
IMG_START_DATE:  17104 TJD;    82 DOY;   15/03/23
IMG_START_TIME:  10310.69 SOD {02:51:50.69} UT,   156.0 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     448771924
X_OFFSET:        1041 [pixels]
Y_OFFSET:        887 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1201
Y_GRB_POS:       1047
BINNING_INDEX:   1
IM_URL:          sw00635887000msuni0170.fits
SUN_POSTN:         1.99d {+00h 07m 56s}   +0.86d {+00d 51' 36"}
SUN_DIST:        114.01 [deg]   Sun_angle= -8.4 [hr] (East of Sun)
MOON_POSTN:       38.35d {+02h 33m 24s}  +12.36d {+12d 21' 26"}
MOON_DIST:        81.32 [deg]
MOON_ILLUM:      11 [%]
GAL_COORDS:      174.84, 36.31 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      118.80, 25.74 [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:     Mon 23 Mar 15 03:02:01 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     635887,   Seg_Num: 0
POINT_RA:        128.206d {+08h 32m 49s} (J2000)
POINT_DEC:       +45.435d {+45d 26' 07"} (J2000)
POINT_ROLL:      298.137d
IMG_START_DATE:  17104 TJD;    82 DOY;   15/03/23
IMG_START_TIME:  10468.72 SOD {02:54:28.72} UT,   314.1 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.569
N_STARS:         24
X_OFFSET:        721 [pixels]
Y_OFFSET:        567 [pixels]
X_MAX:           1680 [pixels]
Y_MAX:           1526 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw00635887000msufc0314.fits
SUN_POSTN:         1.99d {+00h 07m 57s}   +0.86d {+00d 51' 42"}
SUN_DIST:        114.01 [deg]   Sun_angle= -8.4 [hr] (East of Sun)
MOON_POSTN:       38.40d {+02h 33m 37s}  +12.37d {+12d 22' 12"}
MOON_DIST:        81.27 [deg]
MOON_ILLUM:      11 [%]
GAL_COORDS:      174.84, 36.31 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      118.80, 25.74 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN Circular #17611
A. Amaral-Rogers (U Leicester), S. D. Barthelmy (GSFC), F. E. Marshall (NASA/GSFC), C. J. Mountford (U Leicester), D. M. Palmer (LANL), B. Sbarufatti (INAF-OAB/PSU) and M. H. Siegel (PSU) report on behalf of the Swift Team:
At 02:49:14 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 150323A (trigger=635887). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 128.191, +45.434 which is
```
   RA(J2000) = 08h 32m 46s
   Dec(J2000) = +45d 26' 03"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a small peak at the time of the trigger, followed by a much larger peak at T+130 s, for a total duration of at least 170 sec. The peak count rate was ~5600 counts/sec (15-350 keV), at ~130 sec after the trigger.
The XRT began observing the field at 02:51:41.2 UT, 146.6 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source located at RA, Dec 128.17951, 45.46355 which is equivalent to:
```
   RA(J2000)  = 08h 32m 43.08s
   Dec(J2000) = +45d 27' 48.8"
```
with an uncertainty of 3.8 arcseconds (radius, 90% containment). This location is 110 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.
A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 3.05 x 10^20 cm^-2 (Willingale et al. 2013).
The initial flux in the 0.1 s image was 3.25e-08 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 156 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 0.03.
Burst Advocate for this burst is A. Amaral-Rogers (aar14 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:     Mon 23 Mar 15 03:02:12 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     635887,   Seg_Num: 0
POINT_RA:        128.206d {+08h 32m 49s} (J2000)
POINT_DEC:       +45.435d {+45d 26' 07"} (J2000)
POINT_ROLL:      298.137d
IMG_START_DATE:  17104 TJD;    82 DOY;   15/03/23
IMG_START_TIME:  10468.72 SOD {02:54:28.72} UT,   314.1 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.569
N_STARS:         24
X_OFFSET:        721 [pixels]
Y_OFFSET:        567 [pixels]
X_MAX:           1680 [pixels]
Y_MAX:           1526 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw00635887000msufc0314.fits
SUN_POSTN:         1.99d {+00h 07m 57s}   +0.86d {+00d 51' 42"}
SUN_DIST:        114.01 [deg]   Sun_angle= -8.4 [hr] (East of Sun)
MOON_POSTN:       38.41d {+02h 33m 37s}  +12.37d {+12d 22' 14"}
MOON_DIST:        81.27 [deg]
MOON_ILLUM:      11 [%]
GAL_COORDS:      174.84, 36.31 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      118.80, 25.74 [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:     Mon 23 Mar 15 03:03:25 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     635887,   Seg_Num: 0
POINT_RA:        128.206d {+08h 32m 49s} (J2000)
POINT_DEC:       +45.435d {+45d 26' 07"} (J2000)
ROLL:            298.137d
IMG_START_DATE:  17104 TJD;    82 DOY;   15/03/23
IMG_START_TIME:  10468.72 SOD {02:54:28.72} UT,   314.1 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     448772082
X_OFFSET:        1041 [pixels]
Y_OFFSET:        887 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1201
Y_GRB_POS:       1047
BINNING_INDEX:   1
IM_URL:          sw00635887000msuni0328.fits
SUN_POSTN:         1.99d {+00h 07m 57s}   +0.86d {+00d 51' 43"}
SUN_DIST:        114.01 [deg]   Sun_angle= -8.4 [hr] (East of Sun)
MOON_POSTN:       38.42d {+02h 33m 40s}  +12.37d {+12d 22' 24"}
MOON_DIST:        81.26 [deg]
MOON_ILLUM:      11 [%]
GAL_COORDS:      174.84, 36.31 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      118.80, 25.74 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 23 Mar 15 03:03:38 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     635887,   Seg_Num: 0
POINT_RA:        128.206d {+08h 32m 49s} (J2000)
POINT_DEC:       +45.435d {+45d 26' 07"} (J2000)
ROLL:            298.137d
IMG_START_DATE:  17104 TJD;    82 DOY;   15/03/23
IMG_START_TIME:  10468.72 SOD {02:54:28.72} UT,   314.1 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     448772082
X_OFFSET:        1041 [pixels]
Y_OFFSET:        887 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1201
Y_GRB_POS:       1047
BINNING_INDEX:   1
IM_URL:          sw00635887000msuni0328.fits
SUN_POSTN:         1.99d {+00h 07m 57s}   +0.86d {+00d 51' 43"}
SUN_DIST:        114.01 [deg]   Sun_angle= -8.4 [hr] (East of Sun)
MOON_POSTN:       38.42d {+02h 33m 41s}  +12.37d {+12d 22' 26"}
MOON_DIST:        81.26 [deg]
MOON_ILLUM:      11 [%]
GAL_COORDS:      174.84, 36.31 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      118.80, 25.74 [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:     Mon 23 Mar 15 03:17:08 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     635887,   Seg_Num: 0
GRB_RA:          128.1790d {+08h 32m 42.96s} (J2000),
                 128.4415d {+08h 33m 45.97s} (current),
                 127.3141d {+08h 29m 15.37s} (1950)
GRB_DEC:         +45.4637d {+45d 27' 49.3"} (J2000),
                 +45.4112d {+45d 24' 40.1"} (current),
                 +45.6341d {+45d 38' 02.8"} (1950)
GRB_ERROR:       3.6 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  17104 TJD;    82 DOY;   15/03/23
IMG_START_TIME:  10476.00 SOD {02:54:36.00} UT,   321.4 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:         2.00d {+00h 08m 00s}   +0.87d {+00d 51' 57"}
SUN_DIST:        113.97 [deg]   Sun_angle= -8.4 [hr] (East of Sun)
MOON_POSTN:       38.55d {+02h 34m 13s}  +12.41d {+12d 24' 20"}
MOON_DIST:        81.12 [deg]
MOON_ILLUM:      11 [%]
GAL_COORDS:      174.80, 36.30 [deg] galactic lon,lat of the burst
ECL_COORDS:      118.78, 25.77 [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:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.58% < P(seren) < 1.1%.

GCN Circular #17612
S. B. Cenko (NASA/GSFC) and D. A. Perley (Caltech) report on behalf of a larger collaboration:
We observed the location of the Swift GRB150323A (Amaral-Rogers et al., GCN 17611) with the robotic Palomar 60 inch telescope. Observations began at 2:57 UT (~ 8 minutes after the Swift trigger) and were obtained in the Sloan r, i, and z filters. In a stacked r-band image with a mid-point of 3:07 UT, we detect a source at the edge of the XRT error circle, with coordinates:
RA: 08:32:42.83 Dec: +45:27:53.5 (J2000.0)
At this time, we measure an r-band magnitude of ~ 20.6 (photometric calibration performed with respect to nearby point sources from SDSS). Given the lack of a quiescent counterpart in SDSS at this location, we consider this likely to be the afterglow of GRB150323A.
Observations are ongoing.
GCN Circular #17613
Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos=E9 A. de Diego (UNAM), Leonid Georgiev (UNAM), Jes=FAs Gonz=E1lez (UNAM), Carlos Rom=E1n-Z=FA=F1iga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report:
We observed the field of GRB 150323A (Amaral-Rogers, et al., GCN 17611) 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 2015/03 23.12 to 2015/03 23.16 UTC (9.6 to 58.8 minutes after the BAT trigger), obtaining a total of 42.6 minutes exposure in the r, i, and z bands.
For the source on the edge of the Swift-XRT error circle (Cenko et al., GCN 17612), in comparison with the SDSS DR9, we obtain the following measurements and upper-limit (3-sigma):
```
  r =3D 21.16 +/- 0.11
  i =3D 20.39 +/- 0.05
  z > 19.30
```
These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. We note that this source appears to be fading during our observation.
We thank the staff of the Observatorio Astron=F3mico Nacional in San Pedro M=E1rtir.
GCN Circular #17615
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team.
Using 1311 s of XRT Photon Counting mode data and 2 UVOT images for GRB 150323A, 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 = 128.17800, +45.46464 which is equivalent to:
```
RA (J2000): 08h 32m 42.72s
Dec (J2000): +45d 27' 52.7"
```
with an uncertainty of 1.9 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 #17616
D. A. Perley (Caltech) and S. B. Cenko (GSFC) report:
Using the Low Resolution Imaging Spectrometer (LRIS) on the Keck I 10m telescope, we acquired a single 900s spectrum of the optical afterglow (Cenko et al., GCN 17612) of GRB 150323A (Amaral-Roger et al., GCN 17611) beginning at 06:11 UT, at the end of evening twilight.
A number of absorption and emission lines are detected in the 1D spectrum, including e.g. Fe II (2344,2374,2383,2585,2599), Mg II (2796,2803), Mg I (2853), OII (3727), OIII (4959, 5007), and H-beta at a common redshift of z=0.593.
We acknowledge S. Kulkarni for the observing time.
GCN Circular #17617
N. P. M. Kuin (UCL-MSSL) and Amaral-Rogers (U Leicester) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 150323A 156 s after the BAT trigger (Amaral-Rogers et al., GCN Circ. 17611). A weak optical afterglow consistent with the XRT position (Goad et al., GCN Circ. 17615) or the P60 position (GCN Circ. 17612) is be present 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           156          306          147         20.53+/-0.30
u_FC               314          564          246         >20.0
white             4066         5702         1635         20.96+/-0.33
v                 5912         6112          197         18.93+/-0.29
u                  314         5291          442         >20.7
u                 4991         5191          197         19.86+/-0.35
w1                4887         5086          197         >20.2
m2                4682         4881          197         >20.9
w2                4272         4472          197         >20.4
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.03 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #17618
A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), J.A. Kennea (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester) and A. Amaral-Rogers report on behalf of the Swift-XRT team:
We have analysed 6.5 ks of XRT data for GRB 150323A (Amaral-Rogers et al. GCN Circ. 17611), from 136 s to 29.5 ks after the BAT trigger. The data comprise 169 s in Windowed Timing (WT) mode (the first 8 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. 17615).
The late-time light curve (from T0+4.1 ks) can be modelled with a power-law decay with a decay index of alpha=0.72 (+0.19, -0.16).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.26 (+0.06, -0.05). The best-fitting absorption column is 6.2 (+/-0.5) x 10^21 cm^-2, at a redshift of 0.593, in addition to the Galactic value of 3.0 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 2.03 (+0.20, -0.19) and a best-fitting absorption column of 4.6 (+1.8, -1.6) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.4 x 10^-11 (4.7 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Galactic foreground: 3.0 x 10^20 cm^-2
Intrinsic column:    4.6 (+1.8, -1.6) x 10^21 cm^-2 at z=0.593
Photon index:	     2.03 (+0.20, -0.19)
```
If the light curve continues to decay with a power-law decay index of 0.72, the count rate at T+24 hours will be 0.012 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.3 x 10^-13 (5.9 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00635887.
This circular is an official product of the Swift-XRT team.
GCN Circular #17626
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 150323A (Amaral-Rogers et al., GCN 17611) starting at 03:23:43 UT, ~34 minutes after the burst. Observations were performed with an automatic sequence in the clear (roughly R), V, and I filters, and the exposure time was 20 s per image. The afterglow reported by Cenko & Perley (GCN 17612) was not detected in any single image, but was marginally detected in the co-add image of 20 clear band images. We estimated the brightness is R~20.3 +/- 0.3 at a mean time of 71.2 minutes after the burst.
GCN Circular #17628
C. B. Markwardt (GSFC), A. Amaral-Rogers (U Leicester), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-235 to T+967 sec from the recent telemetry downlink, we report further analysis of BAT GRB 150323A (trigger #635887) (Amaral-Rogers, et al., GCN Circ. 17611). The BAT ground-calculated position is RA, Dec = 128.173, 45.442 deg which is
```
  RA(J2000)  =  08h 32m 41.52s
  Dec(J2000) =  +45d 26' 29.76"
```
with an uncertainty of 2.07 arcmin, (radius, sys+stat, 90% containment). The partial coding was 32%.
The mask-weighted light curve shows a multi-peaked structure with two main pulses. The first weaker pulse starts at ~ T0, peaks at ~ T+7 s, and ends at ~ T+25 s. The second brighter pulse starts at ~ T+125 s , peaks at ~ T+135 s, and ends at ~ T+160 s. T90 (15-350 keV) is 149.6 +- 8.9 sec (estimated error including systematics).
The time-averaged spectrum from T+2.6 to T+195.4 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.85 +- 0.07. The fluence in the 15-150 keV band is 6.1 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+135.64 sec in the 15-150 keV band is 5.4 +- 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/635887/BA/
GCN Circular #17640
S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, report:
The long-duration GRB 150323A (Swift-BAT trigger #635887: Amaral-Rogers et al., GCN 17611; Markwardt et al., GCN 17628) triggered Konus-Wind at T0=10282.369 s UT (02:51:22.369).
The burst light curve shows a weak precursor at ~T0-135 s, which triggered BAT, followed by the main episode which started at ~T0-3 s and has a duration of ~38 s. The emission is seen up to ~5 MeV.
As observed by Konus-Wind, the burst had a fluence of 1.1(-0.1,+0.1)x10^-5 erg/cm2, and a 64-ms peak energy flux, measured from T0+0.152 s, of 1.2(-0.6,+0.6)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum of the burst (measured from T0 to T0+24.832 s) is best fit in the 20 keV - 10 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -1.22(-0.28,+0.32), and Ep = 95(-13,+16) keV (chi2 = 70/98 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -2.80 (chi2 = 70/97 dof).
The spectrum near the peak count rate (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 3 MeV range by the power law with exponential cutoff model with alpha = -1.21(-0.26,+0.30), and Ep = 121(-18,+25) keV (chi2 = 71/68 dof). Fitting by a GRB (Band) model yields almost the same alpha and Ep, and an upper limit on the high energy photon index: beta < -2.43 (chi2 = 71/67 dof).
Assuming the redshift z=0.593 (Perley and Cenko, GCN 17616) and a standard cosmology model with H_0 = 70 km/s/Mpc, Omega_M = 0.27, and Omega_Lambda = 0.73, we estimate the following rest-frame parameters: the isotropic energy release 1.0(-0.1,+0.1)x10^52 erg, the peak luminosity L_iso is 1.7(-0.8,+0.8)x10^51 erg/s, and the rest-frame peak energy of the time-integrated spectrum, Ep,i, is 151(-21,+25) keV.
The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB150323_T10282/
All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.
GCN Circular #17642
J. Kelemen (kelemen at konkoly.hu) on behalf of the GRB OT observing program at the Konkoly Observatory.
Starting on the evening 23/03/2015 18:30 UT we observed the field GRB 150323A (A. Amaral-Rogers et al. GCN 17611, and M.R. Goad et al. GCN 17615). We can confirm the presence of the supposed afterglow reported by S. B. Cenko (NASA/GSFC) and D. A. Perley (Caltech) (GCN 17612) at the position
RA: 08:32:42.69 DEC: 45:27:53.6
Our position and the P60 position are the same within 1 pixel.
On the coadded images (total exposure time = 2400 sec) we measured an R -band magnitude of m(R) = 20.3 +/- 0.14 with respect to nearby USNO-B1.0 stars.
```
time from GRB.    exp    filter        Mag.      
------------------------------------------------
 56136 s.       2400 s     R       20.3 +/-0.14
------------------------------------------------ 
```
GCN Circular #17647
E. Mazaeva (IKI), R. Inasaridze (AAO), Sh. Makandarashvili (AAO), A. Volnova (IKI), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration:
We observed the field of the Swift GRB 150323A (Amaral-Rogers et al., GCN 17611) with AS-32 (0.7m) telescope of Abastumani Observatory starting on Mar. 23 (UT) 22:47:06. Within the enhanced XRT position (Goad et al., GCN 17615) we do not detect any object. An upper limit is following
```
Date          UT start     t-T0        Filter    Exp.      UL(3 sigma)
                          (mid, days)                (s)

2015-03-23 22:47:06    0.85076  None    15*180   21.2
```
The photometry is based on nearby USNO-B1.0 stars.

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Jochen Greiner, last update: 26-Mar-2015 [Disclaimer]