Gamma-ray Burst 141222A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN Circular #17218
  J. McEnery (GSFC), D. Kocevski (GSFC), J. Racusin (GSFC), F. Longo (University of Trieste and INFN), E.Bissaldi (University of Trieste and INFN), and M. Axelsson (KTH Royal Institute of Technology) report on behalf of the Fermi-LAT team:
  At 07:09:04 UT Mon on Month 22, 2014, Fermi-LAT detected high-energy emission from GRB 141222A, which was also detected by Fermi-GBM (trigger 440924940/141222298).
  The best LAT on-ground location is found to be RA, Dec 178.04, -57.35 (J2000) with an error radius of 0.1 deg (90% containment, statistical error only) based on a 500s integration. This was 46 deg from the LAT boresight at the time of the trigger.
  The data from the Fermi-LAT show a significant increase in the event rate within 15 degree of the GBM location after the GBM trigger that is spatially and temporally correlated with the GBM emission with high significance. More than 5 photons above 100 MeV and more than 1 photon above 1 GeV are observed within 1 seconds. The highest-energy prompt photon is a 20 GeV event which is observed 0.1 seconds after the GBM trigger.
  The Fermi-LAT point of contact for this burst is Magnus Axelsson (magnusa@astro.su.se ).
  The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.
• GCN Circular #17220
  P. Jenke (UAH) reports on behalf of the Fermi GBM Team:
  "At 07:08:57.40 UT on December 22 2014, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 141222A (trigger 440924940/141222298), which was also detected by Fermi/LAT (J. McEnery et al. 2014, GCN 17218). The GBM on-ground location, using the Fermi GBM trigger data, is consistent with the Fermi/LAT location.
  The angle of the burst direction to the Fermi LAT boresight is 46 degrees.
  The GBM light curve consists of a narrow peak followed by a broad peak with a tail. The duration (T90) is about 2.4 s (50-300 keV). The time-averaged spectrum from T0-0.06 s to T0+1.41 s is adequately fit by a Band function with Epeak = 2427 +/- 580 keV, Alpha =-1.49 +/- 0.01 and Beta = -1.74 +/- 0.05.
  The event fluence (10-1000 keV) in this time interval is (8.16 +/- 0.08)E-06 erg/cm^2. The 64 ms peak photon flux measured starting from T0+0.64 s in the 10-1000 keV band is 121 +/- 3 ph/s/cm^2.
  The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
• GCN Circular #17223
  S. Golenetskii, R. Aptekar, V. Pal'shin, D. Frederiks, D. Svinkin, and T. Cline on behalf of the Konus-Wind team,
  K. Hurley and J. Goldsten, on behalf of the MESSENGER NS GRB team,
  V. Connaughton, M. S. Briggs, C. Meegan, and V. Pelassa, and A. Goldstein, on behalf of the Fermi GBM team, and
  A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, report:
  The hard-spectrum, very intense GRB 141222A has been observed by Fermi (GBM: Jenke, GCN Circ. 17220; LAT: McEnery et al., GCN Circ. 17218), Konus-Wind, INTEGRAL (SPI-ACS), and MESSENGER (GRNS), so far, at about 25737 s UT (07:08:57).
  We have triangulated it to a preliminary, 3 sigma error box whose coordinates are:

    ---------------------------------------------
     RA(2000), deg                 Dec(2000), deg
    ---------------------------------------------
    Center:
     178.156 (11h 52m 38s) -57.280 (-57d 16' 47")
    Corners:
     178.029 (11h 52m 07s) -57.604 (-57d 36' 15")
     178.063 (11h 52m 15s) -57.239 (-57d 14' 20")
     178.284 (11h 53m 08s) -56.954 (-56d 57' 15")
     178.250 (11h 53m 00s) -57.321 (-57d 19' 15")
    ---------------------------------------------
  

  The error box area is 138 sq. arcmin, and its maximum dimension is 40 arcmin (the minimum one is 6 arcmin).
  This box may be improved.
  The box overlaps with about a half of the Fermi-LAT error circle, reported in GCN Circular 17218, with the center of the circle lying slightly outside the box.
  A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB141222_T25735/IPN/
  The Konus-Wind time history and spectrum will be given in a forthcoming GCN Circular.
• GCN Circular #17224
  D.Buckley, S. Potter, A. Kniazev South African Astronomical Observatory
  E. Gorbovskoy,V. Lipunov, P.Balanutsa, D.Denisenko, M.Pruzhinskaya,A.Kuznetsov, V.Kornilov, D.Kuvshinov, N.Tyurina Lomonosov Moscow State University, Sternberg Astronomical Institute
  O.Gres, K.Ivanov, S.Yazev, N.M.Budnev, V.A.Poleshchuk Irkutsk State University
  V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov Blagoveschensk Educational State University
  A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory
  V.Krushinsky, I.Zalozhnih, A. Popov Ural Federal University, Kourovka
  H. Levato and C. Saffe Instituto de Ciencias Astronomicas de la Tierra y del Espacio (ICATE), San Juan, Argentina
  C. Mallamacci, C. Lopez and F. Podest Observatorio Astronomico Felix Aguilar (OAFA), San Juan National University, Argentina
  MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) instaleted several days ago in South African Astronomical Observatory (Sutherland) automaticaly was pointed to the Fermi_LAT GRB141222A (McEnery et al., GCN 17218) after error box rised at 2014-12-22 22:34:35 UT (15.5 hours after trigger time) in unfiltered regime.
  Because we have no reference images we can only use DSS stars. There is no any optical transients brighter 20.8 unfiltered magnitude inside error box (between 2014-12-22 22:34:35 and 2014-12-23 00:26:09).
  We note that error box has small Galactic Latitude b = 4.3 but no very big absorption in R and I, they are 0.9 and 0.7 correspondently (Schlafly & Finkbeiner 2011, ApJ 737, 103).
  This message may be cited.
• GCN Circular #17225
  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, hard-spectrum, very intense GRB 141222A (Fermi-LAT detection: McEnery et al., GCN Circ. 17218; IPN triangulation: Golenetskii et al., GCN Circ. 17223) triggered Konus-Wind at T0=25735.342 s UT (07:08:55.342).
  The burst light curve starts with a short bright pulse with negligible spectral lag followed by two broader, less intense, pulses. The total burst duration is about 3.2 s. The emission is seen up to 5 MeV.
  The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB141222_T25735/ The background variations in the soft KW band are due to solar activity.
  As observed by Konus-Wind, the burst had a fluence of 1.1(-0.2,+0.4)x10^-5 erg/cm2, and a 16-ms peak flux, measured from T0+0.038 s, of 1.2(-0.3,+0.3)x10^-4 erg/cm2/s (both in the 20 keV - 10 MeV energy range).
  The time-averaged spectrum of the burst (measured from T0 to T0+8.448 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 = -1.50 (-0.10,+0.12) and Ep = 858 (-375,+1067) keV (chi2 = 89/79 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -1.9 (chi2 = 89/78 dof).
  The spectrum near the maximum count rate (measured from T0 to T0+0.064 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 = -0.78 (-0.15,+0.17) and Ep = 1532 (-359,+493) keV (chi2 = 25/29 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -2.2 (chi2 = 25/28 dof).
  All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.
• GCN Circular #17226
  M. De Pasquale (IASF/INAF Palermo) and M. Siegel (PSU) report on behalf of the Swift-XRT team:
  We have analysed 4.7 ks of XRT data for GRB 141222A, detected by the Fermi/LAT (McEnery et al. GCN 17218), Fermi/GBM (Jenke et al., GCN 17220) and IPN (Svinkin et al. GCN 17223), from 42.0 ks to 53.4 ks after the Fermi/LAT trigger. The data are entirely in Photon Counting (PC) mode. No source is detected within the LAT error circle; we determined a 3 sigma upper limit of 2.3e-3 count/s at the LAT coordinates.
  The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00020454.
  The Swift/UVOT began settled observations of the field of GRB 141222 41986 s after the LAT trigger. =A0No optical afterglow is detected in the initial UVOT exposures within the LAT error circle. =A0Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposures are:

  Filter =A0 =A0 =A0 =A0 T_start(s) =A0 T_stop(s) =A0 =A0 =A0Exp(s) =A0 =A0=
   =A0 =A0 Mag
  
  v =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A041986 =A0 =A0 =A0 =A053434 =A0 =A0 =A0 =A0=
   2510 =A0 =A0 =A0 =A0 >20.5
  u =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A043226 =A0 =A0 =A0 =A050158 =A0 =A0 =A0 =A0=
   2375 =A0 =A0 =A0 =A0 >20.5
  

  The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) =3D 0.42 in the direction of the burst (Schlegel et al. 1998).