Gamma-ray Burst 160107A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN/BACODINE POSITION NOTICE
  

  TITLE:           GCN/MAXI NOTICE
  NOTICE_DATE:     Thu 07 Jan 16 23:20:00 UT
  NOTICE_TYPE:     MAXI Unknown Source Position
  EVENT_ID_NUM:    394729601     
  EVENT_RA:        299.71d {+19h 58m 50s} (J2000),
                   299.90d {+19h 59m 37s} (current),
                   299.09d {+19h 56m 23s} (1950)
  EVENT_DEC:        +6.45d {+06d 26' 49"} (J2000),
                    +6.49d {+06d 29' 29"} (current),
                    +6.31d {+06d 18' 37"} (1950) 
  EVENT_ERROR:     1.0 [deg radius, stat+sys, 90% containment]
  EVENT_FLUX:      654.0 +- 0.0 [mCrab] 
  EVENT_DATE:      17394 TJD;     7 DOY;   16/01/07
  EVENT_TIME:      80412.00 SOD {22:20:12.00} UT
  EVENT_TSCALE:    30s
  EVENT_EBAND:     Low, 2-4 keV  
  SUN_POSTN:       288.53d {+19h 14m 06s}  -22.34d {-22d 20' 38"}
  SUN_DIST:         30.91 [deg]  
  MOON_POSTN:      260.95d {+17h 23m 47s}  -18.16d {-18d 09' 19"}
  MOON_DIST:        45.66 [deg]  
  MOON_ILLUM:      5 [%]
  GAL_COORDS:       46.60,-11.84 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      303.39, 26.51 [deg] ecliptic lon,lat of the burst (or transient)
  COMMENTS:        MAXI Unknown Source Position. GRB or unknown X-ray Transient.
  

• GCN Circular #18839
  Y. E. Nakagawa (JAXA), H. Negoro (Nihon U.), M. Serino (RIKEN), S. Ueno, H. Tomida, S. Nakahira, M. Ishikawa (JAXA), T. Mihara, M. Sugizaki, M. Shidatsu, J. Sugimoto, T. Takagi, M. Matsuoka (RIKEN), N. Kawai, M. Arimoto, T. Yoshii, Y. Tachibana, Y. Ono, T. Fujiwara (Tokyo Tech), Y. Kawakubo, A. Yoshida, T. Sakamoto, H. Ohtsuki (AGU), H. Tsunemi, R. Imatani (Osaka U.), M. Nakajima, K. Tanaka, T. Masumitsu (Nihon U.), Y. Ueda, T. Kawamuro, T. Hori, A. Tanimoto (Kyoto U.), Y. Tsuboi, S. Kanetou, Y. Nakamura, R. Sasaki (Chuo U.), M. Yamauchi, D. Itoh, K. Furuya (Miyazaki U.), K. Yamaoka (Nagoya U.), M. Morii (ISM) report on behalf of the MAXI team:
  The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient source at 22:19:56 UT on 2016 January 7. Assuming that the source flux was constant over the transit, we obtain the source position at (R.A., Dec) = (299.670 deg, 6.413 deg) = (19 58 40, +06 24 46) (J2000) with a statistical 90% C.L. elliptical error region with long and short radii of 0.20 deg and 0.15 deg, respectively. The roll angle of long axis from the north direction is 151.0 deg counterclockwise. There is an additional systematic uncertainty of 0.1 deg (90% containment radius). The X-ray flux averaged over the scan was 366 +- 42 mCrab (4-10keV, 1 sigma error). Without assumptions on the source constancy, we obtain a rectangular error box for the transient source with the following corners:

  (298.905 deg, 6.966 deg) = (19 55 37, +06 57 57) (J2000)
  (299.190 deg, 7.260 deg) = (19 56 45, +07 15 36) (J2000)
  (300.076 deg, 6.261 deg) = (20 00 18, +06 15 38) (J2000)
  (299.789 deg, 5.968 deg) = (19 59 09, +05 58 03) (J2000)
  

  There was no significant excess flux in the previous transit at 20:47 UT on 2016 January 7 and in the next transit at 23:52 UT on 2016 January 7 with an upper limit of 20 mCrab for each.
  For more information: http://maxi.riken.jp/alert/novae/7394729601/7394729601.htm
• GCN Circular #18844
  P Veres (UAH) and C Meegan (UAH) report on behalf of the Fermi GBM Team:
  "At 2016-01-07 22:20:41.50 UT on 7 January 2016, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 160107A (trigger 473898045 / 160107931), which was also detected by the MAXI/GSC (Nakagawa et al., GCN 18839). The GBM on-ground location is consistent with the MAXI position.
  The trigger resulted in an Autonomous Repoint Request (ARR) by the GBM Flight Software owing to the high peak flux of the GRB. This ARR was accepted and the spacecraft slewed to the GBM in-flight location. The initial angle from the Fermi LAT boresight to the best location is 62 degrees.
  The GBM light curve consists of multiple peaks with a duration (T90) of about 114 s (50-300 keV). The time-averaged spectrum from T0-0.5 s to T0+110 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.79 +/- 0.02 and the cutoff energy, parameterized as Epeak, is 54.5 +/- 2.6 keV.
  The event fluence (10-1000 keV) in this time interval is (3.63 +/- 0.06)E-5 erg/cm^2. The 1-sec peak photon flux measured starting from T0+27.7 s in the 10-1000 keV band is 16.8 +/- 0.3 ph/s/cm^2.
  A Band function fits the spectrum equally well with Epeak = 50.8 +/- 3.1 keV, alpha = -1.75 +/- 0.03 and beta = -2.47 +/- 0.14.
  The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
• GCN Circular #18845
  S. Nakahira (JAXA), A. Yoshida, T. Sakamoto, I. Takahashi, Y. Kawakubo, K. Senuma, M. Moriyama, Y. Yamada (AGU), K. Yamaoka (Nagoya U), Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), M. L. Cherry (LSU), S. Ricciarini (U of Florence) P. S. Marrocchesi (U of Siena) and the CALET collaboration:
  The long-duration GRB 160107A (MAXI/GSC, Nakagawa et al. GCN Circ. 18839; Fermi-GBM, Veres et al. GCN Circ. 18844) triggered the CALET Gamma-Ray Burst Monitor (CGBM) at 22:20:43.20 UT on 7 January 2016. The clear burst signal was detected by all instruments.
  The light curve of the HXM shows at least three peaks starting and ending at T0 and T0+25 sec, T0+25 sec and T0+50 sec, and T0+52 sec and T0+80 sec, respectively. The T90 duration measured by the SGM data is 116.0 s +/- 12.5 sec (40-1000 keV).
  The CGBM data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University.
• GCN Circular #18857
  S. Golenetskii, R.Aptekar, D. Frederiks, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, A. Kozlova and T. Cline on behalf of the Konus-Wind team, report:
  The long-duration GRB 160107A (MAXI/GSC detection: Nakagawa et al., GCN 18839; Fermi GBM observation: Veres & Meegan, GCN 18844; CALET Gamma-Ray Burst Monitor detection: Nakahira et al., GCN 18845) triggered Konus-Wind at T0=80440.646 s UT (22:20:40.646).
  The burst light curve shows multiple, partly overlapped peaks in the interval from ~T0-40 s to ~T0+110 s. The emission is seen up to ~5 MeV.
  As observed by Konus-Wind, the burst had a fluence of 2.48(-0.28,+0.54)x10^-5 erg/cm2, and a 64-ms peak energy flux, measured from T0+25.232 s, of 5.86(-1.22,+1.39)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+106.752 s) is best fit in the 20 keV - 5 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -1.75(-0.16,+0.18), and Ep = 131(-36,+85) keV (chi2 = 83/77 dof). Fitting by the GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -2.0 (chi2 = 82/76 dof).
  The spectrum near the peak count rate (measured from T0+24.832 to T0+33.024 s) is best fit in the 20 keV - 3 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -1.52(-0.16,+0.18), and Ep = 198(-43,+86) keV (chi2 = 49/68 dof). Fitting by the GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -2.1 (chi2 = 49/67 dof).
  The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB160107_T80440/
  All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.