Analysis Summary

Notes:

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.46
    Process Start Time: Tue Jun 21 09:01:57 EDT 2016
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger686818
======================================================================

  Trigger: 00686818      Segment: 000

  BAT Trigger Time: 485309869.824   [s; MET]
      Trigger Stop: 485309870.336   [s; MET]
               UTC: 2016-05-19T00:17:33.535660    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 71.1133226475316   Dec: 31.1966191090885  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.39
     Image Trigger?:     NO
     Rate S/N Ratio:     8.36660026534076  [ if not an image trigger ]
     Image S/N Ratio:    7.39

  Analysis Position:   [ source = BAT ]
    RA: 71.1133226475316   Dec: 31.1966191090885  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 71.1217848321925   Dec: 31.2451441526404  [deg; J2000]  
        { 04h 44m 29.2s , +31d 14' 42.5" }
         +/- 2.20060926015604 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.95986648148545 [arcmin] (formal 1-sigma fit error)
    SNR: 9.85760310765386
 
  Angular difference between the analysis and refined position is 2.943701 arcmin
 
  Partial Coding Fraction: 0.1972656    [ including projection effects ]

  Duration
     T90: 35.6160000562668 +/- 6.06931693447473
        Measured from: -0.480000019073486
                   to: 35.1360000371933     [s; relative to TRIGTIME]
     T50: 24.5440000295639 +/- 7.46397852117202
        Measured from: 0.991999983787537
                   to: 25.5360000133514     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.156000018119812     
                   to: 0.843999981880188     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.991999983787537     
                   to: 41.1520000100136     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.647506   0.823296   0.416430   0.080598
           0.093573   0.096430   0.081626   0.069383 [error]
 Peak      0.077973   0.110899   0.076218   0.043241
           0.016219   0.018262   0.015066   0.012111 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   42.144   -0.992   41.152
T90    35.616   -0.480   35.136
T50    24.544    0.992   25.536
Peak    1.000   -0.156    0.844
 
 
====== 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      -1.971    -0.261      0.244       -           -               -         3.01e-03     -5.09e-04          4.94e-04      47.610   57
CPL     -1.515    -0.646      1.298       45.754      N/A           N/A         5.47e-03        N/A               N/A         47.060   56
 
 
=== 1-s peak 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      -1.723     -0.327     0.308       -           -               -         1.78e-02     -3.63e-03          3.54e-03      52.050   57
CPL     -1.336     -0.951     1.567       81.879     -75.507       -81.879      2.87e-02     -2.87e-02          1.71e-01      51.750   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   2.53e-07  3.49e-07  3.56e-07  6.61e-07  1.17e-06  1.62e-06   erg/cm2
      90%_error_low -4.92e-08 -4.79e-08 -7.99e-08 -2.55e-07 -1.86e-07 -3.53e-07   erg/cm2
      90%_error_hi   5.08e-08  4.79e-08  8.10e-08  3.40e-07  1.89e-07  4.16e-07   erg/cm2
Peak flux       PL   9.10e-01  8.02e-01  4.86e-01  4.45e-01  2.39e+00  2.64e+00   ph/cm2/s
      90%_error_low -2.55e-01 -1.52e-01 -1.25e-01 -1.90e-01 -4.49e-01 -4.91e-01   ph/cm2/s
      90%_error_hi   2.71e-01  1.51e-01  1.23e-01  2.54e-01  4.50e-01  4.93e-01   ph/cm2/s
 
Fluence        CPL   2.42e-07  3.69e-07  3.53e-07  3.07e-07  1.12e-06  1.27e-06   erg/cm2
      90%_error_low -5.63e-08 -1.12e-07 -9.21e-08 -2.47e-07 -2.08e-07 -3.39e-07   erg/cm2
      90%_error_hi   5.55e-08  6.95e-08  8.69e-08  5.63e-07  2.15e-07  7.00e-07   erg/cm2
Peak flux      CPL   8.62e-01  8.40e-01  5.01e-01  2.84e-01  2.36e+00  2.49e+00   ph/cm2/s
      90%_error_low -2.95e-01 -1.82e-01 -1.33e-01 -2.84e-01 -4.56e-01 -5.35e-01   ph/cm2/s
      90%_error_hi   3.03e-01  2.04e-01  1.40e-01  2.25e-01  4.56e-01  5.37e-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
   71.1218    31.2451   0.0195    41.5058   -55.2835         1.9709131      9.858 TRIG_00686818                 
 
Foreground time interval of the image:
 -0.992  41.152 (delta_t =  42.144 [sec])
Background time interval of the image:
-239.824  -0.992 (delta_t = 238.832 [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   -0.992 sec. to   41.152 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.97137     ( -0.261164   0.24445 )
Norm@50keV  : 3.00914E-03    ( -0.000508709   0.000493704 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          47.61 using 59 PHA bins.
# Reduced chi-squared =         0.8353 for     57 degrees of freedom 
# Null hypothesis probability =   8.077117e-01
 
Photon flux (15-150 keV)    in 42.14 sec: 0.445562 ( -0.061664  0.061705 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.16803e-06 ( -1.85935e-07  1.89326e-07 ) ergs/cm2
    Cutoff power-law model
    Time interval is from   -0.992 sec. to   41.152 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.51462     ( -0.646098   1.2979 )
Epeak [keV] : 45.7541      (   )
Norm@50keV  : 5.47464E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          47.06 using 59 PHA bins.
# Reduced chi-squared =         0.8404 for     56 degrees of freedom 
# Null hypothesis probability =   7.967730e-01
 
Photon flux (15-150 keV)    in 42.14 sec: 0.438885 ( -0.063933  0.063473 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.12172e-06 ( -2.0804e-07  2.15166e-07 ) ergs/cm2

    1-s peak spectrum fit

    Power-law model
    Time interval is from   -0.156 sec. to    0.844 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.72325     ( -0.327013   0.308438 )
Norm@50keV  : 1.78309E-02    ( -0.00362524   0.00353786 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          52.05 using 59 PHA bins.
# Reduced chi-squared =         0.9131 for     57 degrees of freedom 
# Null hypothesis probability =   6.609528e-01
 
Photon flux (15-150 keV)    in 1 sec: 2.38781 ( -0.44888  0.4495 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.64839e-07 ( -3.4252e-08  3.46734e-08 ) ergs/cm2
    Cutoff power-law model
    Time interval is from   -0.156 sec. to    0.844 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.33639     ( -0.950516   1.56691 )
Epeak [keV] : 81.8788      ( -75.5072 -81.8788 )
Norm@50keV  : 2.86760E-02    ( -0.028676   0.171497 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          51.75 using 59 PHA bins.
# Reduced chi-squared =         0.9242 for     56 degrees of freedom 
# Null hypothesis probability =   6.362707e-01
 
Photon flux (15-150 keV)    in 1 sec: 2.36371 ( -0.45635  0.45581 ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2

    Time-resolved spectra




    Distribution

    T90 vs. Hardness ratio plot 

    T90                                   = 35.616 sec.
Hardness ratio (energy fluence ratio) = 1.0200936495

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

    S(15-50 keV)  = 6.011344e-07
S(50-150 keV) = 5.669047e-07

    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 = 5.039675259548826E-01, IMY = 7.273743243995497E-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:
-239.824000 -0.992000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6350  22.0181    0.3  27.1  -53.1   9.2845  33.2    0.2	Crab                          
141.1728  41.9816    3.3  54.3   21.1   4.6743   3.5 ------	UNKNOWN                       
 99.8724   4.5904    2.3   3.8  -37.7   1.0257   5.1 ------	UNKNOWN                       
 91.0721  -0.9630    2.8  10.5 -116.3   0.8670   4.2 ------	UNKNOWN                       
 67.7195 -28.7463    3.2  43.9 -150.4   1.5544   3.6 ------	UNKNOWN                       
 57.4707 -41.0310    3.0  57.9 -156.7   5.3420   3.9 ------	UNKNOWN

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

    Time interval of the image:
-0.992000 41.152000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.7546  21.8718    7.2  26.9  -53.1  -0.1605  -1.6   10.9	Crab                          
 71.1218  31.2451    1.2  41.5  -55.3   1.9708   9.9 ------	UNKNOWN

    Post-slew image of 15-350 keV band 

    Time interval of the image:
484.376590 790.976580
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.5702 -40.6698    3.4  37.1  156.0   1.6010   3.4    7.2	Vela X-1                      
148.9575 -18.2490    3.5  24.2  111.8   1.1311   3.3 ------	UNKNOWN                       
128.0454  34.6146    2.5  38.7  -16.6   1.6620   4.6 ------	UNKNOWN                       
 91.7656 -37.0233    2.8  47.3 -154.6   2.5264   4.2 ------	UNKNOWN                       
 82.2300 -27.6865    2.6  50.2 -138.7   5.0744   4.4 ------	UNKNOWN