Gamma-ray Burst 151228A

(All information courtesy of the instrument teams.)

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Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 28 Dec 15 03:05:35 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     668543,   Seg_Num: 0
GRB_RA:          214.004d {+14h 16m 01s} (J2000),
                 214.225d {+14h 16m 54s} (current),
                 213.315d {+14h 13m 15s} (1950)
GRB_DEC:         -17.689d {-17d 41' 19"} (J2000),
                 -17.763d {-17d 45' 45"} (current),
                 -17.457d {-17d 27' 25"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       1434 [cnts]    Image_Peak=91 [image_cnts]
TRIGGER_DUR:     0.256 [sec] 
TRIGGER_INDEX:   481     E_range: 50-350 keV
BKG_INTEN:       17258 [cnts]
BKG_TIME:        11096.38 SOD {03:04:56.38} UT
BKG_DUR:         8 [sec]
GRB_DATE:        17384 TJD;   362 DOY;   15/12/28
GRB_TIME:        11112.38 SOD {03:05:12.38} UT
GRB_PHI:         -167.18 [deg]
GRB_THETA:        14.19 [deg]
SOLN_STATUS:     0x20000083
RATE_SIGNIF:     36.85 [sigma]
IMAGE_SIGNIF:    6.53 [sigma]
MERIT_PARAMS:     +1  +0  +0  -2  +3  -4  +0  +0 -52  +0 
SUN_POSTN:       276.58d {+18h 26m 18s}  -23.30d {-23d 17' 55"}
SUN_DIST:         58.23 [deg]   Sun_angle= 4.2 [hr] (West of Sun)
MOON_POSTN:      130.47d {+08h 41m 52s}  +14.56d {+14d 33' 43"}
MOON_DIST:        88.65 [deg]
MOON_ILLUM:      92 [%]
GAL_COORDS:      329.89, 40.71 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      217.67, -3.83 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This is a rate trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        Since the IMAGE_SIGNIF is less than 7 sigma, this is a questionable detection.  
COMMENTS:        This trigger occurred at longitude,latitude = 72.94,-19.44 [deg]. 
COMMENTS:           
COMMENTS:        NOTE: This BAT event is temporally(0.0<100sec) coincident with the FERMI_GBM event (trignum=472964716).

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Mon 28 Dec 15 03:05:50 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      57
TRIGGER_NUM:     472964716
GRB_RA:          218.810d {+14h 35m 14s} (J2000),
                 219.032d {+14h 36m 08s} (current),
                 218.117d {+14h 32m 28s} (1950)
GRB_DEC:         -17.100d {-17d 06' 00"} (J2000),
                 -17.169d {-17d 10' 08"} (current),
                 -16.882d {-16d 52' 54"} (1950)
GRB_ERROR:       5.68 [deg radius, statistical only]
DATA_SIGNIF:     14.20 [sigma]
DATA_INTERVAL:   0.256 [sec]
GRB_DATE:        17384 TJD;   362 DOY;   15/12/28
GRB_TIME:        11112.46 SOD {03:05:12.46} UT
GRB_PHI:         294.00 [deg]
GRB_THETA:       118.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   4153 (Gnd S/W Version number)
SUN_POSTN:       276.58d {+18h 26m 19s}  -23.30d {-23d 17' 55"}
SUN_DIST:         54.01 [deg]   Sun_angle= 3.8 [hr] (West of Sun)
MOON_POSTN:      130.47d {+08h 41m 53s}  +14.56d {+14d 33' 42"}
MOON_DIST:        92.92 [deg]
MOON_ILLUM:      92 [%]
GAL_COORDS:      335.55, 39.11 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      221.83, -1.80 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2015/bn151228129/quicklook/glg_lc_medres34_bn151228129.gif
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        Bright hard burst in the GBM.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file will not be created/available until ~15 min after the trigger.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(0.0<100sec) coincident with the SWIFT_BAT event (trignum=668543).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Mon 28 Dec 15 03:05:40 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      46
TRIGGER_NUM:     472964716
GRB_RA:          217.867d {+14h 31m 28s} (J2000),
                 218.085d {+14h 32m 21s} (current),
                 217.184d {+14h 28m 44s} (1950)
GRB_DEC:         -14.233d {-14d 13' 59"} (J2000),
                 -14.303d {-14d 18' 11"} (current),
                 -14.012d {-14d 00' 44"} (1950)
GRB_ERROR:       9.70 [deg radius, statistical plus systematic]
GRB_INTEN:       529 [cnts/sec]
DATA_SIGNIF:     8.30 [sigma]
INTEG_TIME:      0.256 [sec]
GRB_DATE:        17384 TJD;   362 DOY;   15/12/28
GRB_TIME:        11112.46 SOD {03:05:12.46} UT
GRB_PHI:         294.00 [deg]
GRB_THETA:       115.00 [deg]
DATA_TIME_SCALE: 0.2560 [sec]
HARD_RATIO:      -0.05
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      98%  GRB
2nd_MOST_LIKELY:   2%  Generic SGR
DETECTORS:       0,0,0, 1,1,0, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       276.58d {+18h 26m 18s}  -23.30d {-23d 17' 55"}
SUN_DIST:         55.75 [deg]   Sun_angle= 3.9 [hr] (West of Sun)
MOON_POSTN:      130.47d {+08h 41m 52s}  +14.56d {+14d 33' 43"}
MOON_DIST:        91.33 [deg]
MOON_ILLUM:      92 [%]
GAL_COORDS:      336.42, 42.04 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      220.07,  0.64 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2015/bn151228129/quicklook/glg_lc_medres34_bn151228129.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 336.48,22.93 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(0.0<100sec) coincident with the SWIFT_BAT event (trignum=668543).

GCN NOTICE

 
TITLE:          GCN/INTEGRAL NOTICE
NOTICE_DATE:    Mon 28 Dec 15 03:05:58 UT
NOTICE_TYPE:    INTEGRAL SPI ACS Trigger 
TRIGGER_NUM:    7321,   Sub_Num: 0
GRB_INTEN:      9.30 [sigma]
GRB_TIME:       11111.78 SOD {03:05:11.78} UT
GRB_DATE:       17384 TJD;   362 DOY;   15/12/28
COMMENTS:       INTEGRAL SPI_ACS GRB Trigger.
COMMENTS:       Time_Scale=1.0000 and Time_Error=0.5000.
COMMENTS:       
COMMENTS:       NOTE: This SPIACS event is temporally(1.0<100sec) coincident with the FERMI_GBM event (trignum=472964716).
COMMENTS:       
COMMENTS:       The SPIACS lightcurve can be found at:
COMMENTS:       ftp://isdcarc.unige.ch/arc/FTP/ibas/spiacs/2015-12/2015-12-28T03-05-11.7063-28117-39824-0.lc

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 28 Dec 15 03:09:09 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     668543,   Seg_Num: 0
GRB_RA:          214.004d {+14h 16m 01s} (J2000),
                 214.225d {+14h 16m 54s} (current),
                 213.315d {+14h 13m 15s} (1950)
GRB_DEC:         -17.689d {-17d 41' 19"} (J2000),
                 -17.763d {-17d 45' 45"} (current),
                 -17.457d {-17d 27' 25"} (1950)
GRB_DATE:        17384 TJD;   362 DOY;   15/12/28
GRB_TIME:        11112.38 SOD {03:05:12.38} UT
TRIGGER_INDEX:   481
GRB_PHI:         -167.18 [deg]
GRB_THETA:        14.19 [deg]
DELTA_TIME:      0.00 [sec]
TRIGGER_DUR:     0.256 [sec] 
SOLN_STATUS:     0x83
RATE_SIGNIF:     36.85 [sigma]
IMAGE_SIGNIF:    6.53 [sigma]
LC_URL:          sw00668543000msb.lc
SUN_POSTN:       276.58d {+18h 26m 19s}  -23.30d {-23d 17' 55"}
SUN_DIST:         58.23 [deg]   Sun_angle= 4.2 [hr] (West of Sun)
MOON_POSTN:      130.50d {+08h 42m 00s}  +14.56d {+14d 33' 20"}
MOON_DIST:        88.62 [deg]
MOON_ILLUM:      92 [%]
GAL_COORDS:      329.89, 40.71 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      217.67, -3.83 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Lightcurve.  
COMMENTS:           
COMMENTS:        The next comments were copied from the BAT_POS Notice:  
COMMENTS:        This is a rate trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        Since the IMAGE_SIGNIF is less than 7 sigma, this is a questionable detection.  
COMMENTS:        This trigger occurred at longitude,latitude = 72.94,-19.44 [deg].

GCN Circular #18731
T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (NASA/UMBC) and K. L. Page (U Leicester) report on behalf of the Swift Team:
At 03:05:12 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 151228A (trigger=668543). Swift did not slew to the burst. The BAT on-board calculated location is RA, Dec 214.004, -17.689, which is
```
   RA(J2000)  =  14h 16m 01s
   Dec(J2000) = -17d 41' 19"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a single spike structure with a duration of about 0.6 sec. The peak count rate was ~6000 counts/sec (15-350 keV), at ~0 sec after the trigger.
Due to an observing constraint, Swift cannot slew to the BAT position. There will thus be no XRT or UVOT data for this trigger.
Burst Advocate for this burst is T. N. Ukwatta (tilan.ukwatta AT gmail.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 Circular #18736
Elisabetta Bissaldi (Politecnico di Bari), Binbin Zhang (UAH) and Peter Veres (UAH) report on behalf of the Fermi GBM Team:
"At 03:05:12.46 UT on 28 December 2015, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 151228A (trigger 472964716 / 151228129), which was also detected by the Swift/BAT (Ukwatta et al. 2015, GCN 18731). The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight at the GBM trigger time is 117 degrees.
The GBM light curve consists of a single peak with a duration (T90) of about 0.26 s (50-300 keV). The time-averaged spectrum from T0-0.06 s to T0+0.32 s is well fit by a power law function with an exponential high-energy cutoff. The power law index is -0.41 +/- 0.23 and the cutoff energy, parameterized as Epeak, is 747 +/- 193 keV.
The event fluence (10-1000 keV) in this time interval is (9.2 +/- 0.8)E-7 erg/cm^2. The 64 ms peak photon flux measured starting from T0-0.06 s in the 10-1000 keV band is 12.4 +/- 2.0 ph/s/cm^2.
The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN Circular #18746
Sonbas, E. (Adiyaman Univ.), Parmaksizoglu, M. (TUG), Guver, T. (Istanbul Univ.), Gogus, E. (Sabanci Univ.), Dindar, M., Kirbiyik, H. (TUG) on behalf of a larger collaboration.
We observed the field of GRB 151228A (Ukwatta et al., GCN #18731) with the 0.60 meter T60 telescope (TUBITAK National Observatory, Antalya - Turkey), starting on December 28, 03:06:43.45 UT (~ 90 sec after the trigger). We obtained 3 x 60 s + 2 x 20 s exposures with R filters under good weather conditions.
We do not detect an optical afterglow within the reported BAT error circle down to a limiting magnitude of >~17 (2-sigma) in the combined R band image.
We thank to TUBITAK National Observatory for a partial support in using T60 telescope with project number 13DT60-539 and technical support.
GCN Circular #18747
Y.Saito, T.Fujiwara, T. Yoshii, Y. Tano, Y. Tachibana, Y.Ono, S.Harita, Y.Muraki, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:
We searched for the optical counterpart of GRB 151228A (T. N. Ukwatta et al., GCN Circular #18731) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan.
The observation started on 2015-12-28 19:25:49 UT (~16.3 h after the burst). We did not find any new point source within BAT circle in all three bands.
We obtained following limits for the magnitudes.
```
T0+[sec]       MID-UT     T-EXP[sec]      g'        Rc             Ic
--------------------------------------------------------------------------------------
58837         20:04:32      4200         > 20.0     > 20.0     > 19.3
---------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
```
We used GSC2.3 catalog for flux calibration.
GCN Circular #18754
S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), 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 downlinks, we report further analysis of BAT GRB 151228A (trigger #668543) (Ukwatta, et al., GCN Circ. 18731). The BAT ground-calculated position is RA, Dec = 214.017, -17.665 deg, which is
```
   RA(J2000)  =  14h 16m 04.0s 
   Dec(J2000) = -17d 39' 52.7" 
```
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%.
The mask-weighted light curve shows a single spike starting at ~T-0.05, peaking at ~T+0.03, and ending at ~T+0.3. T90 (15-350 keV) is 0.27 +- 0.01 sec (estimated error including systematics).
The time-averaged spectrum from T-0.036 to T+0.276 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 0.85 +- 0.20. The fluence in the 15-150 keV band is 8.4 +- 1.1 x 10^-8 erg/cm2. The 1-sec peak photon flux measured from T-0.38 sec in the 15-150 keV band is 0.9 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/668543/BA/
GCN Circular #18770
A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), D.N. Burrows (PSU), T.G.R. Roegiers (PSU), L.M. McCauley (PSU), C. Pagani (U. Leicester), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester) and T.N. Ukwatta report on behalf of the Swift-XRT team:
We have analysed xx ks of XRT data for GRB 151228A (Ukwatta et al. GCN Circ. 18731), from xx to 0 s after the BAT trigger. The data are entirely in Photon Counting (PC) mode. We cannot determine at the present time whether the source is fading.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00668543.
This circular is an official product of the Swift-XRT team.
GCN Circular #18772
K.L. Page (U. Leicester) reports on behalf of the Swift-XRT team:
We apologise for the incomplete nature of GCN 18770, which was automatically sent out in error. The correct information is given below:
We have analysed 2.2 ks of XRT data for GRB 151228A (Ukwatta et al., GCN Circ. 18731), from 178.6 to 196.5 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. No X-ray source is detected in or near to the BAT refined error circle (Barthelmy et al., GCN Circ. 18754), to a 3-sigma upper limit of 7x10^-3 count s^-1, corresponding to an approximate observed flux of 3x10^-13 erg cm^-2 s^-1.
This circular is an official product of the Swift-XRT team.

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Jochen Greiner, last update: 30-Dec-2015 [Disclaimer]