batgrbproduct Analysis for Trigger=643833

Analysis Summary

Notes:

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.46
    Process Start Time (local time): Fri Jul 10 23:58:17 EDT 2015
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger643833
======================================================================

  Trigger: 00643833      Segment: 000

  BAT Trigger Time: 456036160.768   [s; MET]
      Trigger Stop: 456036168.96   [s; MET]
               UTC: 2015-06-15T04:42:27.048040    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 107.570242386832   Dec: -22.471915183491  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    10.52
     Image Trigger?:     NO
     Rate S/N Ratio:     14.142135623731  [ if not an image trigger ]
     Image S/N Ratio:    10.52

  Flight Position:   [ source = BAT ]
    RA: 107.570242386832   Dec: -22.471915183491  [deg; J2000]

  Ground Position:   [ source = BAT pre-slew burst ]
    RA: 107.544771652447   Dec: -22.4681600613637  [deg; J2000]  
        { 07h 10m 10.7s , -22d 28' 05.4" }
         +/- 1.83988874689869 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.934000086233514 [arcmin] (formal 1-sigma fit error)
    SNR: 12.7304782220261
 
  Angular difference between Flight and Ground position is 1.430079 arcmin
 
  Partial Coding Fraction: 0.8515625    [ including projection effects ]

  Duration
     T90: 32.6839999556541 +/- 7.48940716116703
        Measured from: -1.95600003004074
                   to: 30.7279999256134     [s; relative to TRIGTIME]
     T50: 13.8359999060631 +/- 5.33741215626278
        Measured from: 3.06800001859665
                   to: 16.9039999246597     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 5.80000001192093     
                   to: 6.80000001192093     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -2.86000001430511     
                   to: 36.4800000190735     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.374145   0.391850   0.247264   0.028964
           0.039414   0.040938   0.035736   0.031677 [error]
 Peak      0.026813   0.023162   0.014257   0.007697
           0.006540   0.006725   0.005902   0.004840 [error]

     [ fluence units of on-axis counts / fully illuminated detector ] 

======================================================================
 
=== Fluence/Peak Flux Summary ===
 
              Model    Band1    Band2    Band3    Band4    Band5    Total      
                       15-25    25-50   50-100  100-350   15-150   15-350   keV
Fluence   Power-law 1.11e-07 1.71e-07 1.96e-07 4.32e-07 6.06e-07 9.10e-07   erg/cm2
              Error 1.88e-08 1.89e-08 3.52e-08 1.59e-07 8.11e-08 1.93e-07   erg/cm2
Peak flux Power-law 2.53e-01 1.99e-01 1.05e-01 8.01e-02 5.94e-01 6.37e-01   ph/cm2/s
              Error 1.03e-01 5.36e-02 5.00e-02 7.73e-02 1.60e-01 1.76e-01   ph/cm2/s
 
Fluence   Cutoff-PL 1.11e-07 1.71e-07 1.96e-07 4.31e-07 6.06e-07 9.11e-07   erg/cm2
              Error 1.90e-08 1.89e-08 3.51e-08 3.13e-07 8.43e-08 2.15e-07   erg/cm2
Peak flux Cutoff-PL 2.57e-01 1.99e-01 1.03e-01 7.63e-02 5.94e-01 6.35e-01   ph/cm2/s
              Error 1.02e-01 4.08e-02 4.86e-02 8.91e-02 1.60e-01 1.32e-01   ph/cm2/s
 
Fluence        Band -------- -------- -------- -------- -------- --------   erg/cm2
              Error -------- -------- -------- -------- -------- --------   erg/cm2
Peak flux      Band -------- -------- -------- -------- -------- --------   ph/cm2/s
              Error -------- -------- -------- -------- -------- --------   ph/cm2/s
 
=== Time-averaged spectral analysis ===
 
Model Ph_index Ph_90err Epeak  Epeak_90err Norm     Nomr_90err chi2   dof
PL    1.798    0.210    -      -           1.67e-03 2.17e-04   41.740 57
CPL   1.777    0.821     448.1    0.0      1.72e-03 0.00e+00   41.760 56
 
 
=== 1-s peak spectral analysis ===
 
Model Ph_index Ph_90err Epeak  Epeak_90err Norm     Nomr_90err chi2   dof
PL    1.924    0.589    -      -           4.09e-03 1.47e-03   59.360 57
CPL   2.749    0.000     241.1    0.0      1.56e-03 0.00e+00   57.780 56
 
Model      : spectral model: simple power-law (PL) and cutoff power-law (CPL)
Ph_index   : photon index: E^-{Ph_index} (minus sign is not included in the index)
Ph_90err   : 90% error of the photon index
Epeak      : Epeak in keV
Epeak_90err: 90% error of Epeak
Norm       : normalization at 50 keV in PL model and at 1 keV in CPL model
Nomr_90err : 90% error of the normalization
chi2       : Chi-Squared
dof        : degree of freedom
 
=== T90/T50 calculation in the 50-300 keV band (BATSE band) using 64 ms lc ===
 
T90 in the 50-300 keV band: 0.000000 sec.
T50 in the 50-300 keV band: 0.000000 sec.
 
=== Table of the duration information ==
 
        Value   tstart    tstop
T100   39.340   -2.860   36.480
T90    32.684   -1.956   30.728
T50    13.836    3.068   16.904
Peak    1.000    5.800    6.800
  • Click here for the BAT GCN circular template
  • Special notes of this burst

    Image

    Pre-slew 15.0-350.0 keV image (Event data)

    #   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
      107.5448   -22.4682   0.0152    28.1396  -176.2403         1.0160731     12.730 TRIG_00643833                 
     
    Foreground time interval of the image:
     -2.860  36.480 (delta_t =  39.340 [sec])
    Background time interval of the image:
    -525.667 -509.378 (delta_t =  16.289 [sec])
    -239.768  -2.860 (delta_t = 236.908 [sec])
    

    Lightcurves

    Notes:

    1 s binning

    From T0-310 s to T0+310 s
    From T100_start - 20 s to T100_end + 30 s
    Full time interval

    64 ms binning

    Full time interval
    From T100_start to T100_end
    From T0-5 sec to T0+5 sec

    16 ms binning

    From T100_start-5 s to T100_start+5 s
    Blue+Cyan dotted lines: Time interval of the scaled map
    From 0.000000 to 8.192000
    

    8 ms binning

    From T100_start-3 s to T100_start+3 s
    Blue+Cyan dotted lines: Time interval of the scaled map
    From 0.000000 to 8.192000
    

    2 ms binning

    From T100_start-1 s to T100_start+1 s
    Blue+Cyan dotted lines: Time interval of the scaled map
    From 0.000000 to 8.192000
    

    SN=5 or 10 sec. binning (whichever binning is satisfied first)

    SN=5 or 10 sec. binning (T < 200 sec)

    Quad-rate summed light curves (from T0-300s to T0+1000s)

    Spectral Evolution

    Spectra

    Notes:

    Time averaged spectrum fit using the average DRM

    Power-law model
    Time interval is from   -2.860 sec. to   36.480 sec.
     
    Spectral model in power-law:
    ------------------------------------------------------------
    Parameters  : value       lower 90%   higher 90%
    Photon index: 1.79834     ( -0.205208   0.213872 )
    Norm@50keV  : 1.67305E-03    ( -0.000220207   0.000214682 )
    ------------------------------------------------------------
    #Fit statistic : Chi-Squared =          41.74 using 59 PHA bins.
    # Reduced chi-squared =         0.7323 for     57 degrees of freedom 
    # Null hypothesis probability =   9.354084e-01
     
    Photon flux (15-150 keV)    in 39.34 sec: 0.230395 ( -0.0256254  0.0256389 ) ph/cm2/s
    Energy fluence (15-150 keV)             : 6.05958e-07 ( -8.03122e-08  8.18012e-08 ) ergs/cm2
     
    
    Cutoff power-law model
    Time interval is from   -2.860 sec. to   36.480 sec.
    Spectral model in the cutoff power-law:
    ------------------------------------------------------------
    Parameters  : value       lower 90%   higher 90%
    Photon index: 1.77674     ( -0.712837   0.930056 )
    Epeak [keV] : 448.064      (   )
    Norm@50keV  : 1.71911E-03    (     )
    ------------------------------------------------------------
    #Fit statistic : Chi-Squared =          41.76 using 59 PHA bins.
    # Reduced chi-squared =         0.7457 for     56 degrees of freedom 
    # Null hypothesis probability =   9.216354e-01
     
    Photon flux (15-150 keV)    in 39.34 sec: 0.230421 ( -0.025736  0.025538 ) ph/cm2/s
    Energy fluence (15-150 keV)             : 6.05982e-07 ( -8.78856e-08  8.07808e-08 ) ergs/cm2
     
    
    Band function
    Time interval is from   -2.860 sec. to   36.480 sec.
     
    Spectral model in the Band function:
    ------------------------------------------------------------
    Parameters  : value       lower 90%   higher 90%
    alpha       : -1.25397   ( 1.25474   5.88024 )
    beta        : -1.83146    ( 1.82777   0.230874 )
    Epeak [keV] : 37.3545      ( -36.603 -36.603 )
    Norm@50keV   : 4.10024E-03    ( -0.00431938   369412 )
    ------------------------------------------------------------
    #Fit statistic : Chi-Squared =          41.64 using 59 PHA bins.
    # Reduced chi-squared =         0.7572 for     55 degrees of freedom 
    # Null hypothesis probability =   9.081092e-01
     
    Photon flux (15-150 keV)    in 39.34 sec:  (    ) ph/cm2/s
    Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2
     
    
    Single BB
     
    Spectral model blackbody:
    ------------------------------------------------------------
    Parameters  : value    Lower 90%  Upper 90%
    kT [keV]    : 10.7905  (-1.53637  1.86103)
    R^2/D10^2   : 7.96649E-02  (-0.0354444   0.0618243)
    (R is the radius in km and D10 is the distance to the source in units of 10 kpc)
    ------------------------------------------------------------
    #Fit statistic : Chi-Squared =          66.59 using 59 PHA bins.
    # Reduced chi-squared =          1.168 for     57 degrees of freedom 
    # Null hypothesis probability =   1.803110e-01
     
    Energy  Fluence     90% Error
    [keV]   [erg/cm2]   [erg/cm2]
    15- 25  7.593e-08   1.583e-08
    25- 50  2.094e-07   3.346e-08
    50-150  1.357e-07   4.074e-08
    15-150  4.210e-07   6.403e-08
    
    Thermal bremsstrahlung (OTTB)
     
     
    Spectral model: thermal bremsstrahlung
    ------------------------------------------------------------
    Parameters  : value         Lower 90%    Upper 90%
    kT [keV]    : 101.394       (-35.2569      84.5345)
    Norm        : 1.01158       (-0.150551     0.183824)
    ------------------------------------------------------------
    #Fit statistic : Chi-Squared =          43.25 using 59 PHA bins.
    # Reduced chi-squared =         0.7587 for     57 degrees of freedom 
    # Null hypothesis probability =   9.107874e-01
     
    Energy  Fluence     90% Error
    [keV]   [erg/cm2]   [erg/cm2]
    15- 25  1.040e-07   1.670e-08
    25- 50  1.804e-07   2.478e-08
    50-150  2.946e-07   1.328e-07
    15-150  5.789e-07   1.572e-07
    
    Double BB
     
     
    Spectral model: bbodyrad<1> + bbodyrad<2>
    ------------------------------------------------------------
    Parameters  : value         Lower 90%    Upper 90%
    kT1 [keV]   : 6.61468        (-1.78232      1.88692)
    R1^2/D10^2  : 0.382360        (-0.221699      0.814433)
    kT2 [keV]   : 28.9390        (-10.4504      36.2606)
    R2^2/D10^2  : 1.65533E-03    (-0.0014688   0.0066615)
    ------------------------------------------------------------
    #Fit statistic : Chi-Squared =          42.08 using 59 PHA bins.
    # Reduced chi-squared =         0.7650 for     55 degrees of freedom 
    # Null hypothesis probability =   8.996486e-01
     
    Energy  Fluence     90% Error
    [keV]   [erg/cm2]   [erg/cm2]
    15- 25  1.080e-07   4.314e-08
    25- 50  1.746e-07   6.379e-08
    50-150  3.340e-07   1.837e-07
    15-150  6.165e-07   2.575e-07
    

    Peak spectrum fit

    Power-law model
    Time interval is from    5.800 sec. to    6.800 sec.
     
    Spectral model in power-law:
    ------------------------------------------------------------
    Parameters  : value       lower 90%   higher 90%
    Photon index: 1.92374     ( -0.53639   0.642354 )
    Norm@50keV  : 4.09380E-03    ( -0.00155178   0.00138386 )
    ------------------------------------------------------------
    #Fit statistic : Chi-Squared =          59.36 using 59 PHA bins.
    # Reduced chi-squared =          1.041 for     57 degrees of freedom 
    # Null hypothesis probability =   3.897269e-01
     
    Photon flux (15-150 keV)    in 1 sec: 0.593515 ( -0.159874  0.159878 ) ph/cm2/s
    Energy fluence (15-150 keV)             : 3.76483e-08 ( -1.27186e-08  1.32612e-08 ) ergs/cm2
     
    
    Cutoff power-law model
    Time interval is from    5.800 sec. to    6.800 sec.
    Spectral model in the cutoff power-law:
    ------------------------------------------------------------
    Parameters  : value       lower 90%   higher 90%
    Photon index: 2.74879     (     )
    Epeak [keV] : 241.143      (   )
    Norm@50keV  : 1.56350E-03    (     )
    ------------------------------------------------------------
    #Fit statistic : Chi-Squared =          57.78 using 59 PHA bins.
    # Reduced chi-squared =          1.032 for     56 degrees of freedom 
    # Null hypothesis probability =   4.094140e-01
     
    Photon flux (15-150 keV)    in 1 sec: 0.593518 ( -0.1598  0.159714 ) ph/cm2/s
    Energy fluence (15-150 keV)             : 3.74906e-08 ( -1.25236e-08  1.31353e-08 ) ergs/cm2
     
    
    Band function
    Time interval is from    5.800 sec. to    6.800 sec.
     
    Spectral model in the Band function:
    ------------------------------------------------------------
    Parameters  : value       lower 90%   higher 90%
    alpha       : -1.49045   ( 1.49414   1.49414 )
    beta        : -1.90864    ( 1.91529   0.528215 )
    Epeak [keV] : 18.7498      ( -14.3303 -14.3303 )
    Norm@50keV   : 1.02335E-02    ( -0.010859   25.0649 )
    ------------------------------------------------------------
    #Fit statistic : Chi-Squared =          59.36 using 59 PHA bins.
    # Reduced chi-squared =          1.079 for     55 degrees of freedom 
    # Null hypothesis probability =   3.196828e-01
     
    Photon flux (15-150 keV)    in 1 sec:  (    ) ph/cm2/s
    Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2
     
    
    Single BB
     
    Spectral model blackbody:
    ------------------------------------------------------------
    Parameters  : value    Lower 90%  Upper 90%
    kT [keV]    : 9.47517  (-2.86261  4.74367)
    R^2/D10^2   : 0.323967  (-0.322885   0.96344)
    (R is the radius in km and D10 is the distance to the source in units of 10 kpc)
    ------------------------------------------------------------
    #Fit statistic : Chi-Squared =          65.70 using 59 PHA bins.
    # Reduced chi-squared =          1.153 for     57 degrees of freedom 
    # Null hypothesis probability =   2.009454e-01
     
    Energy  Fluence     90% Error
    [keV]   [erg/cm2]   [erg/cm2]
    15- 25  5.802e-09   3.588e-09
    25- 50  1.334e-08   7.980e-09
    50-150  5.943e-09   4.552e-09
    15-150  2.509e-08   1.604e-08
    
    Thermal bremsstrahlung (OTTB)
     
     
    Spectral model: thermal bremsstrahlung
    ------------------------------------------------------------
    Parameters  : value         Lower 90%    Upper 90%
    kT [keV]    : 90.9382       (-90.9867      -90.9867)
    Norm        : 2.64167       (-0.891282     1.81969)
    ------------------------------------------------------------
    #Fit statistic : Chi-Squared =          60.55 using 59 PHA bins.
    # Reduced chi-squared =          1.062 for     57 degrees of freedom 
    # Null hypothesis probability =   3.490122e-01
     
    Energy  Fluence     90% Error
    [keV]   [erg/cm2]   [erg/cm2]
    15- 25  6.895e-09   4.253e-09
    25- 50  1.169e-08   7.235e-09
    50-150  1.791e-08   1.438e-08
    15-150  3.649e-08   2.475e-08
    
    Double BB
     
     
    Spectral model: bbodyrad<1> + bbodyrad<2>
    ------------------------------------------------------------
    Parameters  : value         Lower 90%    Upper 90%
    kT1 [keV]   : 2.27179        (-1.7886      8.20755)
    R1^2/D10^2  : 188.625        (-183.874      970.657)
    kT2 [keV]   : 14.4746        (-13.6043      -14.5093)
    R2^2/D10^2  : 5.74743E-02    (-0.0558511   0.0844825)
    ------------------------------------------------------------
    #Fit statistic : Chi-Squared =          60.08 using 59 PHA bins.
    # Reduced chi-squared =          1.092 for     55 degrees of freedom 
    # Null hypothesis probability =   2.969127e-01
     
    Energy  Fluence     90% Error
    [keV]   [erg/cm2]   [erg/cm2]
    15- 25  7.547e-09   4.007e-09
    25- 50  9.984e-09   5.915e-09
    50-150  1.366e-08   8.880e-09
    15-150  3.119e-08   1.784e-08
    

    Pre-slew spectrum (Pre-slew PHA with pre-slew DRM)

    Power-law model
     
    Spectral model in power-law:
    ------------------------------------------------------------
    Parameters  : value       lower 90%   higher 90%
    Photon index: 1.79834     ( -0.205208   0.213872 )
    Norm@50keV  : 1.67305E-03    ( -0.000220207   0.000214682 )
    ------------------------------------------------------------
    #Fit statistic : Chi-Squared =          41.74 using 59 PHA bins.
    # Reduced chi-squared =         0.7323 for     57 degrees of freedom 
    # Null hypothesis probability =   9.354084e-01
     
    Photon flux (15-150 keV)    in 39.34 sec: 0.230395 ( -0.0256254  0.0256389 ) ph/cm2/s
    Energy fluence (15-150 keV)             : 6.05958e-07 ( -8.03122e-08  8.18012e-08 ) ergs/cm2
     
    
    Cutoff power-law model
    Spectral model in the cutoff power-law:
    ------------------------------------------------------------
    Parameters  : value       lower 90%   higher 90%
    Photon index: 1.77674     ( -0.712837   0.930056 )
    Epeak [keV] : 448.064      (   )
    Norm@50keV  : 1.71911E-03    (     )
    ------------------------------------------------------------
    #Fit statistic : Chi-Squared =          41.76 using 59 PHA bins.
    # Reduced chi-squared =         0.7457 for     56 degrees of freedom 
    # Null hypothesis probability =   9.216354e-01
     
    Photon flux (15-150 keV)    in 39.34 sec: 0.230421 ( -0.025736  0.025538 ) ph/cm2/s
    Energy fluence (15-150 keV)             : 6.05982e-07 ( -8.78856e-08  8.07808e-08 ) ergs/cm2
     
    
    Band function
     
    Spectral model in the Band function:
    ------------------------------------------------------------
    Parameters  : value       lower 90%   higher 90%
    alpha       : -1.25397   ( 1.25474   5.88024 )
    beta        : -1.83146    ( 1.82777   0.230874 )
    Epeak [keV] : 37.3545      ( -36.603 -36.603 )
    Norm@50keV   : 4.10024E-03    ( -0.00431938   369412 )
    ------------------------------------------------------------
    #Fit statistic : Chi-Squared =          41.64 using 59 PHA bins.
    # Reduced chi-squared =         0.7572 for     55 degrees of freedom 
    # Null hypothesis probability =   9.081092e-01
     
    Photon flux (15-150 keV)    in 39.34 sec:  (    ) ph/cm2/s
    Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2
     
    

    S(25-50 keV) vs. S(50-100 keV) plot

    S(25-50 keV)  = 1.71e-07
    S(50-100 keV) = 1.96e-07
    

    T90 vs. Hardness ratio plot

    T90                                   = 32.6839999556541 sec.
    Hardness ratio (energy fluence ratio) = 1.1462
    

    Color vs. Color plot

    Count Ratio  (25-50 keV) / (15-25 keV) = 1.04732
    Count Ratio (50-100 keV) / (15-25 keV) = 0.660877
    

    Mask shadow pattern

    IMX = -5.336869788725411E-01, IMY = 3.507030346768814E-02
    

    TIME vs. PHA plot around the trigger time

    Blue+Cyan dotted lines: Time interval of the scaled map
    From 0.000000 to 8.192000
    

    TIME vs. DetID plot around the trigger time

    Blue+Cyan dotted lines: Time interval of the scaled map
    From 0.000000 to 8.192000
    

    100 us light curve (15-350 keV)

    Blue+Cyan dotted lines: Time interval of the scaled map
    From 0.000000 to 8.192000
    

    Spacecraft aspect plot

    Bright source in the pre-burst/pre-slew/post-slew images

    Pre-burst image of 15-350 keV band

    Time interval of the image:
    -525.667390 -509.378000
    -239.768000 -2.860000
     
    # RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
    #  [deg]    [deg]    ['] [deg]  [deg]                   [']
    135.7477 -40.5403    5.2  36.3  127.9  -1.2975  -2.2   10.0	Vela X-1                      
    116.6947 -16.2374    2.5  17.5 -177.4   0.8873   4.7 ------	UNKNOWN                       
    155.8634  39.8514    2.3  50.4  -19.0   2.4790   5.0 ------	UNKNOWN                       
     71.6646 -25.4295    5.1  59.6 -161.6   4.1579   2.3 ------	UNKNOWN                       
    138.3436  41.3486    3.2  46.6  -36.1   1.5611   3.6 ------	UNKNOWN                       
     85.9397   6.2256    2.3  45.3 -121.3   4.5613   5.2 ------	UNKNOWN                       
     85.6492   6.0650    2.5  45.6 -121.6   4.4702   5.0 ------	UNKNOWN                       
    

    Pre-slew background subtracted image of 15-350 keV band

    Time interval of the image:
    -2.860000 36.480000
     
    # RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
    #  [deg]    [deg]    ['] [deg]  [deg]                   [']
    135.3840 -40.5932    5.7  36.3  128.4   0.3541   2.0    7.0	Vela X-1                      
    107.5448 -22.4681    0.9  28.1 -176.2   1.0159  12.7 ------	UNKNOWN                       
    

    Post-slew image of 15-350 keV band

    Time interval of the image:
    101.732590 962.364100
     
    # RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
    #  [deg]    [deg]    ['] [deg]  [deg]                   [']
    135.5861 -40.7238    4.2  29.8   73.4  -2.9771  -2.7   10.5	Vela X-1                      
     46.4020 -38.3878    3.5  54.1  177.1   7.3952   3.3 ------	UNKNOWN                       
    137.9974  20.0759    3.2  51.9  -23.7   5.1722   3.6 ------	UNKNOWN                       
    136.8881  26.7800    3.4  56.8  -29.4  12.7934   3.4 ------	UNKNOWN                       
     69.0304   3.2291    3.0  45.6 -121.5   9.6825   3.8 ------	UNKNOWN                       
    
    Plot creation:
    Sat Jul 11 00:43:01 EDT 2015