Analysis Summary

Notes:

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.46
    Process Start Time: Sat Jan 20 10:32:58 EST 2018
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger783479
======================================================================

  Trigger: 00783479      Segment: 000

  BAT Trigger Time: 530785406.528   [s; MET]
      Trigger Stop: 530785410.624   [s; MET]
               UTC: 2017-10-27T08:23:06.622860    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 61.6803931109227   Dec: -2.60607661453514  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    10.64
     Image Trigger?:     NO
     Rate S/N Ratio:     19.4164878389476  [ if not an image trigger ]
     Image S/N Ratio:    10.64

  Analysis Position:   [ source = BAT ]
    RA: 61.6803931109227   Dec: -2.60607661453514  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 61.682508830707   Dec: -2.60030518316982  [deg; J2000]  
        { 04h 06m 43.8s , -02d 36' 01.1" }
         +/- 1.10010075033232 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.551651207375305 [arcmin] (formal 1-sigma fit error)
    SNR: 26.5417253068916
 
  Angular difference between the analysis and refined position is 0.368775 arcmin
 
  Partial Coding Fraction: 0.9140625    [ including projection effects ]

  Duration
     T90: 96.7719999551773 +/- 4.9069697352188
        Measured from: 7.67199999094009
                   to: 104.443999946117     [s; relative to TRIGTIME]
     T50: 29.567999958992 +/- 1.31383402806664
        Measured from: 44.1280000209808
                   to: 73.6959999799728     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 62.2639999985695     
                   to: 63.2639999985695     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -1.09600001573563     
                   to: 129.98400002718     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     3.313078   4.698913   3.638017   0.875773
           0.071947   0.076349   0.067335   0.055179 [error]
 Peak      0.083522   0.150750   0.134317   0.028664
           0.007113   0.008270   0.007422   0.005382 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  131.080   -1.096  129.984
T90    96.772    7.672  104.444
T50    29.568   44.128   73.696
Peak    1.000   62.264   63.264
 
 
====== Spectral Analysis Summary =====================================
 
Model      : spectral model: simple power-law (PL) and cutoff power-law (CPL)
Ph_index   : photon index: E^{Ph_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 both the PL model and CPL model
Nomr_90err : 90% error of the normalization
chi2       : Chi-Squared
dof        : degree of freedo
 
=== Time-averaged spectral analysis ===
(Best model with acceptable fit: PL)
 
Model Ph_index Ph_90err_low Ph_90err_hi  Epeak  Epeak_90err_low  Epeak_90err_hi  Norm       Nomr_90err_low    Norm_90err_hi    chi2    dof
PL      -1.459    -0.042      0.042       -           -               -         6.19e-03     -1.34e-04          1.34e-04      56.860   57
CPL     -1.301    -0.085      0.169      248.618     -99.246      -248.618      7.27e-03     -9.79e-04          1.34e-03      54.150   56
 
 
=== 1-s peak spectral analysis ===
(Best model with acceptable fit: CPL)
 
Model Ph_index Ph_90err_low Ph_90err_hi  Epeak  Epeak_90err_low  Epeak_90err_hi  Norm       Nomr_90err_low    Norm_90err_hi    chi2    dof
PL      -1.176     -0.098     0.099       -           -               -         2.59e-02     -1.53e-03          1.53e-03      41.890   57
CPL     -0.507     -0.424     0.471      120.229     -29.091       108.758      5.39e-02     -1.96e-02          3.46e-02      34.280   56
 
 
=== 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         PL   9.96e-07  1.88e-06  2.73e-06  8.47e-06  7.75e-06  1.41e-05   erg/cm2
      90%_error_low -4.53e-08 -4.91e-08 -7.17e-08 -5.13e-07 -1.76e-07 -5.46e-07   erg/cm2
      90%_error_hi   4.61e-08  4.90e-08  7.15e-08  5.36e-07  1.76e-07  5.64e-07   erg/cm2
Peak flux       PL   7.82e-01  9.55e-01  8.45e-01  1.29e+00  3.03e+00  3.87e+00   ph/cm2/s
      90%_error_low -8.49e-02 -6.55e-02 -5.76e-02 -1.74e-01 -1.83e-01 -2.43e-01   ph/cm2/s
      90%_error_hi   8.79e-02  6.50e-02  5.73e-02  1.90e-01  1.83e-01  2.46e-01   ph/cm2/s
 
Fluence        CPL   9.56e-07  1.89e-06  2.77e-06  6.88e-06  7.66e-06  1.25e-05   erg/cm2
      90%_error_low -5.99e-08 -5.14e-08 -8.06e-08 -1.30e-06 -1.96e-07 -1.30e-06   erg/cm2
      90%_error_hi   6.11e-08  5.16e-08  8.12e-08  1.58e-06  1.95e-07  1.53e-06   erg/cm2
Peak flux      CPL   6.76e-01  1.01e+00  9.07e-01  6.72e-01  2.96e+00  3.26e+00   ph/cm2/s
      90%_error_low -1.05e-01 -7.52e-02 -7.01e-02 -2.11e-01 -1.89e-01 -2.87e-01   ph/cm2/s
      90%_error_hi   1.08e-01  7.64e-02  7.13e-02  3.28e-01  1.89e-01  3.63e-01   ph/cm2/s
 
======================================================================
  • 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
       61.6825    -2.6003   0.0073    17.7237    37.5020         2.1965366     26.542 TRIG_00783479                 
     
    Foreground time interval of the image:
     -1.096  37.573 (delta_t =  38.669 [sec])
    Background time interval of the image:
    -254.627  -1.096 (delta_t = 253.531 [sec])
    




    Light Curves

    Note: The mask-weighted lightcurves have units of either count/det or counts/sec/det, where a det is 0.4 x 0.4 = 0.16 sq cm.

    Full-time range; 1 s binning

    Bokeh Plot

    Other quick-look light curves:




    Spectra

    Notes:

    Time averaged spectrum fit using the average DRM

    Power-law model
    Time interval is from   -1.096 sec. to  129.984 sec.
     
    Spectral model in power-law:
    ------------------------------------------------------------
    Parameters  : value       lower 90%   higher 90%
    Photon index: -1.45896     ( -0.0422959   0.0423226 )
    Norm@50keV  : 6.18550E-03    ( -0.000134139   0.000134134 )
    ------------------------------------------------------------
    #Fit statistic : Chi-Squared =          56.86 using 59 PHA bins.
    # Reduced chi-squared =         0.9976 for     57 degrees of freedom 
    # Null hypothesis probability =   4.801383e-01
     
    Photon flux (15-150 keV)    in 131.1 sec: 0.764003 ( -0.018701  0.018762 ) ph/cm2/s
    Energy fluence (15-150 keV)             : 7.74823e-06 ( -1.75848e-07  1.761e-07 ) ergs/cm2
     
    
    Cutoff power-law model
    Time interval is from   -1.096 sec. to  129.984 sec.
    Spectral model in the cutoff power-law:
    ------------------------------------------------------------
    Parameters  : value       lower 90%   higher 90%
    Photon index: -1.30101     ( -0.0846607   0.169422 )
    Epeak [keV] : 248.618      ( -99.2454 -248.618 )
    Norm@50keV  : 7.27436E-03    ( -0.00097881   0.00133965 )
    ------------------------------------------------------------
    #Fit statistic : Chi-Squared =          54.15 using 59 PHA bins.
    # Reduced chi-squared =         0.9669 for     56 degrees of freedom 
    # Null hypothesis probability =   5.453597e-01
     
    Photon flux (15-150 keV)    in 131.1 sec: 0.754139 ( -0.021063  0.021158 ) ph/cm2/s
    Energy fluence (15-150 keV)             : 7.66466e-06 ( -1.95997e-07  1.95346e-07 ) ergs/cm2
     
    

    1-s peak spectrum fit

    Power-law model
    Time interval is from   62.264 sec. to   63.264 sec.
     
    Spectral model in power-law:
    ------------------------------------------------------------
    Parameters  : value       lower 90%   higher 90%
    Photon index: -1.1758     ( -0.098407   0.098982 )
    Norm@50keV  : 2.59003E-02    ( -0.0015287   0.0015287 )
    ------------------------------------------------------------
    #Fit statistic : Chi-Squared =          41.89 using 59 PHA bins.
    # Reduced chi-squared =         0.7350 for     57 degrees of freedom 
    # Null hypothesis probability =   9.331281e-01
     
    Photon flux (15-150 keV)    in 1 sec: 3.03022 ( -0.18273  0.18288 ) ph/cm2/s
    Energy fluence (15-150 keV)             : 2.64631e-07 ( -1.73561e-08  1.74345e-08 ) ergs/cm2
     
    
    Cutoff power-law model
    Time interval is from   62.264 sec. to   63.264 sec.
    Spectral model in the cutoff power-law:
    ------------------------------------------------------------
    Parameters  : value       lower 90%   higher 90%
    Photon index: -0.506636     ( -0.424246   0.470522 )
    Epeak [keV] : 120.229      ( -29.091 108.757 )
    Norm@50keV  : 5.38758E-02    ( -0.0196049   0.0346464 )
    ------------------------------------------------------------
    #Fit statistic : Chi-Squared =          34.28 using 59 PHA bins.
    # Reduced chi-squared =         0.6122 for     56 degrees of freedom 
    # Null hypothesis probability =   9.902392e-01
     
    Photon flux (15-150 keV)    in 1 sec: 2.95890 ( -0.18893  0.18851 ) ph/cm2/s
    Energy fluence (15-150 keV)             : 2.54812e-07 ( -1.87914e-08  1.87464e-08 ) ergs/cm2
     
    

    Time-resolved spectra




    Distribution

    T90 vs. Hardness ratio plot

    T90                                   = 96.772 sec.
    Hardness ratio (energy fluence ratio) = 1.45505732586
    

    S(15-50 keV) vs. S(50-150 keV) plot

    S(15-50 keV)  = 2.8738226e-06
    S(50-150 keV) = 4.874419e-06
    

    The dash-dotted line and the dashed line traces the fluences calculated from the Band function with Epeak = 15 and 150 keV, respectively. Both lines assume a canonical values of alpha = -1 and beta = -2.5.




    Mask shadow pattern

    IMX = 2.535455495875235E-01, IMY = -1.945664264299750E-01
    

    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:
    -254.627410 -1.096000
     
    # RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
    #  [deg]    [deg]    ['] [deg]  [deg]                   [']
     83.6228  22.0181    0.3  17.4  174.9  10.3038  43.6    0.6	Crab                          
     61.6568   0.9257    2.7  16.4   48.6   1.1159   4.3 ------	UNKNOWN                       
    105.8944  37.6068    2.3  41.1 -169.8   1.9158   4.9 ------	UNKNOWN                       
    

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

    Time interval of the image:
    -1.096000 37.572600
     
    # RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
    #  [deg]    [deg]    ['] [deg]  [deg]                   [']
     83.4838  22.0578   21.3  17.4  174.4   0.0406   0.5    8.7	Crab                          
     35.8652   7.9023    2.0  41.2   70.6   1.8266   5.7 ------	UNKNOWN                       
     35.7261   2.9221    1.7  41.6   63.0   1.9527   6.8 ------	UNKNOWN                       
     38.6004 -36.7457    2.1  55.8   12.4   2.5068   5.5 ------	UNKNOWN                       
     61.6825  -2.6004    0.4  17.7   37.5   2.1966  26.5 ------	UNKNOWN                       
     62.3081 -48.3345    2.0  55.6  -12.9   1.5611   5.7 ------	UNKNOWN                       
    

    Post-slew image of 15-350 keV band

    Time interval of the image:
    76.572590 962.531700
     
    # RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
    #  [deg]    [deg]    ['] [deg]  [deg]                   [']
     83.6155  22.0231    0.2  32.7 -168.2  30.2487  52.2    1.1	Crab                          
     27.3476  20.3242    2.4  40.7   97.7   9.5653   4.9 ------	UNKNOWN                       
     61.1391  46.3811    2.9  49.0  151.4   8.2866   4.0 ------	UNKNOWN                       
     61.6526  -2.6051    1.5   0.0   82.5   4.0119   7.9 ------	UNKNOWN                       
     78.1239  -3.2216    3.3  16.4 -115.6   1.9024   3.5 ------	UNKNOWN                       
    112.0216  27.9501    3.0  57.2 -154.1  14.5080   3.9 ------	UNKNOWN                       
    100.6154 -12.6706    4.2  39.8 -101.4   6.7954   2.8 ------	UNKNOWN