Gamma-ray Burst 181222A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN/BACODINE POSITION NOTICE
  

  TITLE:           GCN/MAXI NOTICE 
  NOTICE_DATE:     Sat 22 Dec 18 07:32:59 UT
  NOTICE_TYPE:     MAXI Unknown Source Position
  EVENT_ID_NUM:    474228283
  EVENT_RA:        270.97d {+18h 03m 54s} (J2000),
                   271.30d {+18h 05m 12s} (current),
                   270.11d {+18h 00m 26s} (1950)
  EVENT_DEC:       -38.70d {-38d 42' 10"} (J2000),
                   -38.70d {-38d 42' 02"} (current),
                   -38.71d {-38d 42' 19"} (1950)
  EVENT_ERROR:     1.0 [deg radius, stat+sys, 90% containment] 
  EVENT_FLUX:      398.0 +- 0.0 [mCrab] 
  EVENT_DATE:      18474 TJD;   356 DOY;   18/12/22
  EVENT_TIME:      24259.00 SOD {06:44:19.00} UT
  EVENT_TSCALE:    30s
  EVENT_EBAND:     Low, 2-4 keV  
  SUN_POSTN:       270.43d {+18h 01m 43s}  -23.44d {-23d 26' 07"}  
  SUN_DIST:         15.28 [deg]  
  MOON_POSTN:       84.04d {+05h 36m 10s}  +20.49d {+20d 29' 41"} 
  MOON_DIST:       160.75 [deg]  
  MOON_ILLUM:      100 [%]       
  GAL_COORDS:      353.42, -8.17 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      270.79,-15.27 [deg] ecliptic lon,lat of the burst (or transient)
  COMMENTS:        MAXI Unknown Source Position. GRB or unknown X-ray Transient.
  

• GCN NOTICE
  

  TITLE:          GCN/INTEGRAL NOTICE
  NOTICE_DATE:    Sat 22 Dec 18 06:42:45 UT
  NOTICE_TYPE:    INTEGRAL SPI ACS Trigger
  TRIGGER_NUM:    8179,   Sub_Num: 0
  GRB_INTEN:      9.03 [sigma]   
  GRB_TIME:       24092.64 SOD {06:41:32.64} UT
  GRB_DATE:       18474 TJD;   356 DOY;   18/12/22
  COMMENTS:       INTEGRAL SPI_ACS GRB Trigger.
  COMMENTS:       Time_Scale=2.0000 and Time_Error=1.0000.
  COMMENTS:
  COMMENTS:       NOTE: This SPIACS event is temporally(2.0<100sec) coincident with the FERMI_GBM event (trignum=567153699).
  COMMENTS:
  COMMENTS:       The SPIACS lightcurve can be found at:
  COMMENTS:       ftp://isdcarc.unige.ch/arc/FTP/ibas/spiacs/2018-12/2018-12-22T06-41-32.5213-21521-56208-0.lc
  

• GCN NOTICE
  

  TITLE:           GCN/FERMI NOTICE
  NOTICE_DATE:     Sat 22 Dec 18 06:42:08 UT
  NOTICE_TYPE:     Fermi-GBM Flight Position
  RECORD_NUM:      51
  TRIGGER_NUM:     567153699
  GRB_RA:          269.033d {+17h 56m 08s} (J2000),
                   269.360d {+17h 57m 26s} (current),
                   268.172d {+17h 52m 41s} (1950)
  GRB_DEC:         -38.367d {-38d 22' 00"} (J2000),
                   -38.368d {-38d 22' 04"} (current),
                   -38.360d {-38d 21' 35"} (1950)
  GRB_ERROR:       3.82 [deg radius, statistical plus systematic]
  GRB_INTEN:       1824 [cnts/sec]
  DATA_SIGNIF:     70.30 [sigma]
  INTEG_TIME:      2.048 [sec]
  GRB_DATE:        18474 TJD;   356 DOY;   18/12/22
  GRB_TIME:        24094.25 SOD {06:41:34.25} UT
  GRB_PHI:         345.00 [deg]
  GRB_THETA:        90.00 [deg]
  DATA_TIME_SCALE: 2.0480 [sec]
  HARD_RATIO:      0.53
  LOC_ALGORITHM:   3 (version number of)
  MOST_LIKELY:      93%  GRB
  2nd_MOST_LIKELY:   4%  Generic Transient
  DETECTORS:       0,0,0, 1,1,0, 0,0,0, 0,0,0, 0,0,
  SUN_POSTN:       270.39d {+18h 01m 33s}  -23.44d {-23d 26' 08"}
  SUN_DIST:         14.96 [deg]   Sun_angle= 0.1 [hr] (West of Sun)
  MOON_POSTN:       83.50d {+05h 33m 59s}  +20.43d {+20d 26' 03"}
  MOON_DIST:       161.36 [deg]
  MOON_ILLUM:      100 [%]
  GAL_COORDS:      352.98, -6.68 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      269.22,-14.93 [deg] ecliptic lon,lat of the burst (or transient)
  LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2018/bn181222279/quicklook/glg_lc_medres34_bn181222279.gif
  COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
  COMMENTS:        This trigger occurred at longitude,latitude = 352.67,-6.85 [deg].  
  COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
  COMMENTS:           
  COMMENTS:        NOTE: This GBM event is temporally(1.0<100sec) coincident with the CALET_GBM event (trignum=1229496031).  
  

• GCN NOTICE
  

  TITLE:           GCN/FERMI NOTICE
  NOTICE_DATE:     Sat 22 Dec 18 06:41:59 UT
  NOTICE_TYPE:     Fermi-GBM Flight Position
  RECORD_NUM:      39
  TRIGGER_NUM:     567153699
  GRB_RA:          269.083d {+17h 56m 20s} (J2000),
                   269.410d {+17h 57m 38s} (current),
                   268.222d {+17h 52m 53s} (1950)
  GRB_DEC:         -38.383d {-38d 22' 59"} (J2000),
                   -38.385d {-38d 23' 04"} (current),
                   -38.377d {-38d 22' 35"} (1950)
  GRB_ERROR:       6.40 [deg radius, statistical plus systematic]
  GRB_INTEN:       1412 [cnts/sec]
  DATA_SIGNIF:     18.30 [sigma]
  INTEG_TIME:      0.256 [sec]
  GRB_DATE:        18474 TJD;   356 DOY;   18/12/22
  GRB_TIME:        24094.25 SOD {06:41:34.25} UT
  GRB_PHI:         345.00 [deg]
  GRB_THETA:        90.00 [deg]
  DATA_TIME_SCALE: 0.2560 [sec]
  HARD_RATIO:      0.52
  LOC_ALGORITHM:   3 (version number of)
  MOST_LIKELY:      93%  GRB
  2nd_MOST_LIKELY:   4%  Generic Transient
  DETECTORS:       0,0,0, 1,1,0, 0,0,0, 0,0,0, 0,0,
  SUN_POSTN:       270.39d {+18h 01m 33s}  -23.44d {-23d 26' 08"}
  SUN_DIST:         14.97 [deg]   Sun_angle= 0.1 [hr] (West of Sun)
  MOON_POSTN:       83.50d {+05h 33m 59s}  +20.43d {+20d 26' 02"}
  MOON_DIST:       161.34 [deg]
  MOON_ILLUM:      100 [%]
  GAL_COORDS:      352.98, -6.72 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      269.26,-14.95 [deg] ecliptic lon,lat of the burst (or transient)
  LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2018/bn181222279/quicklook/glg_lc_medres34_bn181222279.gif
  COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
  COMMENTS:        This trigger occurred at longitude,latitude = 352.67,-6.85 [deg].  
  COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
  COMMENTS:           
  COMMENTS:        NOTE: This GBM event is temporally(1.0<100sec) coincident with the CALET_GBM event (trignum=1229496031).  
  

• GCN NOTICE
  

  TITLE:           GCN/FERMI NOTICE
  NOTICE_DATE:     Sat 22 Dec 18 06:42:11 UT
  NOTICE_TYPE:     Fermi-GBM Ground Position
  RECORD_NUM:      50
  TRIGGER_NUM:     567153699
  GRB_RA:          271.580d {+18h 06m 19s} (J2000),
                   271.904d {+18h 07m 37s} (current),
                   270.726d {+18h 02m 54s} (1950)
  GRB_DEC:         -37.440d {-37d 26' 23"} (J2000),
                   -37.437d {-37d 26' 11"} (current),
                   -37.446d {-37d 26' 43"} (1950)
  GRB_ERROR:       2.70 [deg radius, statistical only]
  DATA_SIGNIF:     -214748364.80 [sigma]
  DATA_INTERVAL:   4.096 [sec]
  GRB_DATE:        18474 TJD;   356 DOY;   18/12/22
  GRB_TIME:        24094.25 SOD {06:41:34.25} UT
  GRB_PHI:         346.00 [deg]
  GRB_THETA:        92.00 [deg]
  E_RANGE:         44.032 - 279.965 [keV]
  LOC_ALGORITHM:   4153 (Gnd S/W Version number)
  SUN_POSTN:       270.39d {+18h 01m 33s}  -23.44d {-23d 26' 08"}
  SUN_DIST:         14.06 [deg]   Sun_angle= -0.1 [hr] (East of Sun)
  MOON_POSTN:       83.50d {+05h 33m 59s}  +20.43d {+20d 26' 03"}
  MOON_DIST:       161.50 [deg]
  MOON_ILLUM:      100 [%]
  GAL_COORDS:      354.77, -7.99 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      271.29,-14.01 [deg] ecliptic lon,lat of the burst (or transient)
  LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2018/bn181222279/quicklook/glg_lc_medres34_bn181222279.gif
  POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_567153699.fits
  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:        The POS_MAP_URL file will not be created/available until ~1.5 min after the notice.  
  COMMENTS:           
  COMMENTS:        NOTE: This GBM event is temporally(1.0<100sec) coincident with the CALET_GBM event (trignum=1229496031).  
  

• GCN NOTICE
  

  TITLE:           GCN/FERMI NOTICE
  NOTICE_DATE:     Sat 22 Dec 18 06:50:46 UT
  NOTICE_TYPE:     Fermi-GBM Final Position
  RECORD_NUM:      0
  TRIGGER_NUM:     567153699
  GRB_RA:          267.620d {+17h 50m 29s} (J2000),
                   267.946d {+17h 51m 47s} (current),
                   266.760d {+17h 47m 02s} (1950)
  GRB_DEC:         -38.310d {-38d 18' 35"} (J2000),
                   -38.314d {-38d 18' 50"} (current),
                   -38.296d {-38d 17' 46"} (1950)
  GRB_ERROR:       1.41 [deg radius, statistical only]
  GRB_DATE:        18474 TJD;   356 DOY;   18/12/22
  GRB_TIME:        24094.25 SOD {06:41:34.25} UT
  GRB_PHI:         345.00 [deg]
  GRB_THETA:        89.00 [deg]
  E_RANGE:         44.032 - 279.965 [keV]
  LOC_ALGORITHM:   41531 (Gnd S/W Version number)
  SUN_POSTN:       270.40d {+18h 01m 35s}  -23.44d {-23d 26' 08"}
  SUN_DIST:         15.02 [deg]   Sun_angle= 0.2 [hr] (West of Sun)
  MOON_POSTN:       83.59d {+05h 34m 22s}  +20.44d {+20d 26' 40"}
  MOON_DIST:       161.74 [deg]
  MOON_ILLUM:      100 [%]
  GAL_COORDS:      352.47, -5.69 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      268.07,-14.89 [deg] ecliptic lon,lat of the burst (or transient)
  LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2018/bn181222279/quicklook/glg_lc_medres34_bn181222279.gif
  LOC_URL:         http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2018/bn181222279/quicklook/glg_locplot_all_bn181222279.png
  COMMENTS:        Fermi-GBM Final Position.  
  COMMENTS:        This Notice was ground-generated -- not flight-generated.  
  COMMENTS:        The LC_URL file should be available by the time this FINAL notice is produced.  
  COMMENTS:        This notice was generated completely by automated pipeline processing.  
  COMMENTS:        Bright hard burst in the GBM.  
  COMMENTS:        This is likely a Long GRB.  
  COMMENTS:           
  COMMENTS:        NOTE: This GBM event is temporally(2.0<100sec) coincident with the INTEGRAL_SPIACS event (trignum=8179).  
  

• GCN Circular #23547
  A. Sakamaki, H. Negoro, M. Nakajima, W. Maruyama, M. Aoki, K. Kobayashi (Nihon U.), T. Mihara, S. Nakahira, F. Yatabe, Y. Takao, M. Matsuoka (RIKEN), T. Sakamoto, M. Serino, S. Sugita, Y. Kawakubo, T. Hashimoto, A. Yoshida (AGU), N. Kawai, M. Sugizaki, Y. Tachibana, K. Morita, T. Oeda, K. Shiraishi (Tokyo Tech), S. Ueno, H. Tomida, M. Ishikawa, Y. Sugawara, N. Isobe, R. Shimomukai, T. Midooka (JAXA), Y. Ueda, A. Tanimoto, T. Morita, S. Yamada, S. Ogawa (Kyoto U.), Y. Tsuboi, W. Iwakiri, R. Sasaki, H. Kawai, T. Sato (Chuo U.), H. Tsunemi, T. Yoneyama, K. Asakura, S. Ide (Osaka U.), M. Yamauchi, K. Hidaka, S. Iwahori (Miyazaki U.), T. Kawamuro (NAOJ), K. Yamaoka (Nagoya U.), M. Shidatsu (Ehime U.) report on behalf of the MAXI team:
  The MAXI/GSC nova alert system triggered on a bright uncatalogued X-ray transient source at 06:44:09 UT on December 22, 2018. Assuming that the source flux was constant over the transit, we obtain the source position at (R.A., Dec) = (270.731 deg, -38.848 deg) = (18 02 55, -38 50 52) (J2000) with a statistical 90% C.L. elliptical error region with long and short radii of 0.13 deg and 0.12 deg, respectively. The roll angle of long axis from the north direction is 132.0 deg counterclockwise. There is an additional systematic uncertainty of 0.1 deg (90% containment radius).
  The X-ray flux averaged over the scan was 350 +- 34 mCrab (4.0-10.0keV, 1 sigma error). Without assumptions on the source constancy, we obtain a rectangular error box for the transient source with the following corners:

  (R.A., Dec) = (270.981, -38.395) deg = (18 03 55, -38 23 42) (J2000)
  (R.A., Dec) = (270.687, -38.351) deg = (18 02 44, -38 21 03) (J2000)
  (R.A., Dec) = (270.409, -39.448) deg = (18 01 38, -39 26 52) (J2000)
  (R.A., Dec) = (270.708, -39.494) deg = (18 02 49, -39 29 38) (J2000)
  

  There was no significant excess flux in the previous transit at 05:11 UT with an upper limit of 20 mCrab.
• GCN Circular #23548
  P. Veres (UAH) and E. Bissaldi (Politecnico & INFN Bari) report on behalf of the Fermi GBM Team:
  "At 06:41:34.25 UT on 22 December 2018, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 181222A (trigger 567153699 / 181222279) which was also detected by MAXI/GSC (Sakamaki et al., GCN 23547). The GBM on-ground location is consistent with the MAXI position.
  The angle from the Fermi LAT boresight at the GBM trigger time is 89 degrees.
  The GBM light curve shows four separate pulses with a duration (T90) of about 131 s (50-300 keV). The time-averaged spectrum from T0-1 s to T0+151 s is adequately fit by a Band function with Epeak = 264 +/- 32 keV, alpha = -0.95 +/- 0.04, and beta = -1.47 +/- 0.01.
  The event fluence (10-1000 keV) in this time interval is (1.83 +/- 0.01)E-4 erg/cm^2. The 1-sec peak photon flux measured starting from T0+94.9 s in the 10-1000 keV band is 74.7 +/- 0.7 ph/s/cm^2.
  The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
• GCN Circular #23553
  T. Sakamoto, A. Yoshida, V. Pal'shin, S. Sugita, Y. Kawakubo, A. Tezuka, S. Matsukawa, H. Onozawa, T. Ito, H. Morita, Y. Sone (AGU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), I. Takahashi (IPMU), Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU), S. Ricciarini (U of Florence), A. V. Penacchioni, P. S. Marrocchesi (U of Siena), and the CALET collaboration:
  The long GRB 181222A (MAXI/GSC detection: Sakamaki et al., GCN Circ. 23547; Fermi-GBM observation: Vere & Bissaldi, GCN Circ. 23548) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 06:41:33.811 UTC on 22 December 2018. The burst signal was seen by all CGBM detectors. Since the burst incident direction was nearly perpendicular to the HXM detector axes, the signal in these detectors was heavily attenuated.
  The burst light curve shows two main emission episodes which start at T+1.5 sec and end at T+105.8 sec. The T90 and the T50 durations measured by the SGM data are 98.3 +- 5.3 sec and 44.6 +- 39.7 sec (40-1000 keV), respectively.
  The ground processed light curve is available at
  http://cgbm.calet.jp/cgbm_trigger/ground/1229496031/
  The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University.
• GCN Circular #23559
  A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, report:
  The long-duration GRB 181222A (MAXI/GSC detection: Sakamaki et al., GCN Circ. 23547; Fermi/GBM observation: Veres & Bissaldi, GCN Circ. 23548; CGBM detection: Sakamoto et al., GCN Circ. 23553) triggered Konus-Wind at T0=24090.989 s UT (06:41:30.989).
  The burst light curve shows a multipeaked structure started at ~T0-1.3 s with a total duration of ~171.5 s. The emission is seen up to ~10 MeV.
  As observed by Konus-Wind, the burst had a fluence of 3.97(-0.33,+0.32)x10^-4 erg/cm2, and a 64-ms peak flux, measured from T0+94.208 s, of 6.71(-0.66,+0.66)x10^-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range).
  The time-averaged spectrum of the burst (measured from T0 to T0+146.688 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -1.05(-0.08,+0.08), the high energy photon index beta = -1.90(-0.12,+0.09), the peak energy Ep = 570(-100,+133) keV (chi2 = 79/84 dof).
  The spectrum near the maximum count rate (measured from T0+93.440 to T0+96.000 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.87(-0.06,+0.06), the high energy photon index beta = -2.01(-0.10,+0.08), the peak energy Ep = 850(-114,+136) keV (chi2 = 115/77 dof).
  The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB181222_T24090/
  All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.
• GCN Circular #23566
  V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:
  Analysis of AstroSat CZTI data showed the detection of a long GRB 181222A, which was also detected by MAXI/GSC (Negoro H. et al., GCN 23547), Fermi/GBM (Veres P. et al., GCN 23548), CALET (Sakamoto T. et al., GCN 23553) and Konus-Wind (Kozlova A. et al., GCN 23559).
  The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with strongest peak at 06:43:09.500 UT. The measured peak count rate is 1720 cts/s above the background in combined data of four quadrants, with a total of 14364 cts. The local mean background count rate was 522 cts/s. Using cumulative rates, we measure a T90 of 117 s. In preliminary analysis, we find that 1258 compton events are associated with this event.
  It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.
  CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.