Analysis Summary

Notes:

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.46
    Process Start Time: Fri Mar  2 16:28:18 EST 2018
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger808625
======================================================================

  Trigger: 00808625      Segment: 000

  BAT Trigger Time: 539497549.76   [s; MET]
      Trigger Stop: 539497550.272   [s; MET]
               UTC: 2018-02-05T04:25:29.331960    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 126.806396594374   Dec: 11.5396155071366  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    10.76
     Image Trigger?:     NO
     Rate S/N Ratio:     23.1516738055805  [ if not an image trigger ]
     Image S/N Ratio:    10.76

  Analysis Position:   [ source = BAT ]
    RA: 126.806396594374   Dec: 11.5396155071366  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 126.819327604964   Dec: 11.5361858423513  [deg; J2000]  
        { 08h 27m 16.6s , +11d 32' 10.3" }
         +/- 1.0956932438053 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.514599591438998 [arcmin] (formal 1-sigma fit error)
    SNR: 26.6943795907834
 
  Angular difference between the analysis and refined position is 0.787542 arcmin
 
  Partial Coding Fraction: 0.5    [ including projection effects ]

  Duration
     T90: 15.5359998941422 +/- 3.14699346489193
        Measured from: -6.31599998474121
                   to: 9.21999990940094     [s; relative to TRIGTIME]
     T50: 6.11199998855591 +/- 0.598264161410583
        Measured from: -4.69200003147125
                   to: 1.41999995708466     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.195999979972839     
                   to: 0.804000020027161     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -7.0440000295639     
                   to: 10.8680000305176     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.754907   0.732596   0.396065   0.059204
           0.038867   0.040049   0.033652   0.027988 [error]
 Peak      0.123548   0.152514   0.108165   0.017881
           0.011139   0.011644   0.010116   0.007477 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   17.912   -7.044   10.868
T90    15.536   -6.316    9.220
T50     6.112   -4.692    1.420
Peak    1.000   -0.196    0.804
 
 
====== 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      -2.036    -0.128      0.124       -           -               -         6.16e-03     -4.83e-04          4.76e-04      58.360   57
CPL     -1.827    -0.282      0.509       36.545      N/A           N/A         8.05e-03        N/A               N/A         57.770   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      -1.725     -0.146     0.142       -           -               -         2.52e-02     -2.31e-03          2.28e-03      68.730   57
CPL     -1.053     -0.572     0.653       68.420     -15.014        98.810      5.62e-02     -2.74e-02          6.41e-02      64.630   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   2.34e-07  3.10e-07  3.03e-07  5.28e-07  1.02e-06  1.37e-06   erg/cm2
      90%_error_low -2.25e-08 -1.96e-08 -3.28e-08 -1.08e-07 -7.41e-08 -1.43e-07   erg/cm2
      90%_error_hi   2.30e-08  1.96e-08  3.31e-08  1.25e-07  7.49e-08  1.56e-07   erg/cm2
Peak flux       PL   1.29e+00  1.13e+00  6.86e-01  6.27e-01  3.37e+00  3.73e+00   ph/cm2/s
      90%_error_low -1.67e-01 -9.70e-02 -8.04e-02 -1.34e-01 -2.87e-01 -3.14e-01   ph/cm2/s
      90%_error_hi   1.73e-01  9.68e-02  8.00e-02  1.53e-01  2.87e-01  3.14e-01   ph/cm2/s
 
Fluence        CPL    N/A      N/A      N/A      N/A      N/A      N/A      erg/cm2
      90%_error_low -2.25e-08 -1.96e-08 -3.28e-08 -1.08e-07 -7.41e-08 -1.43e-07   erg/cm2
      90%_error_hi   2.30e-08  1.96e-08  3.31e-08  1.25e-07  7.49e-08  1.56e-07   erg/cm2
Peak flux      CPL   1.15e+00  1.21e+00  7.20e-01  3.13e-01  3.29e+00  3.40e+00   ph/cm2/s
      90%_error_low -2.02e-01 -1.18e-01 -9.03e-02 -1.39e-01 -2.97e-01 -3.38e-01   ph/cm2/s
      90%_error_hi   2.05e-01  1.21e-01  9.22e-02  2.55e-01  2.96e-01  3.75e-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
  126.8193    11.5362   0.0072    26.0457    87.8532         1.9887556     26.694 TRIG_00808625                 
 
Foreground time interval of the image:
 -7.044  10.868 (delta_t =  17.912 [sec])
Background time interval of the image:
-239.760  -7.044 (delta_t = 232.716 [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   -7.044 sec. to   10.868 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.03639     ( -0.128216   0.124096 )
Norm@50keV  : 6.16328E-03    ( -0.000483306   0.000475738 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          58.36 using 59 PHA bins.
# Reduced chi-squared =          1.024 for     57 degrees of freedom 
# Null hypothesis probability =   4.250441e-01
 
Photon flux (15-150 keV)    in 17.91 sec: 0.940380 ( -0.060763  0.06085 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.02039e-06 ( -7.40736e-08  7.48928e-08 ) ergs/cm2
    Cutoff power-law model
    Time interval is from   -7.044 sec. to   10.868 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.82652     ( -0.281602   0.508529 )
Epeak [keV] : 36.5453      (   )
Norm@50keV  : 8.04746E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          57.77 using 59 PHA bins.
# Reduced chi-squared =          1.032 for     56 degrees of freedom 
# Null hypothesis probability =   4.095863e-01
 
Photon flux (15-150 keV)    in 17.91 sec: 0.929891 ( -0.064852  0.064653 ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2

    1-s peak spectrum fit

    Power-law model
    Time interval is from   -0.196 sec. to    0.804 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.72493     ( -0.146312   0.142265 )
Norm@50keV  : 2.51720E-02    ( -0.00230686   0.00228199 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          68.73 using 59 PHA bins.
# Reduced chi-squared =          1.206 for     57 degrees of freedom 
# Null hypothesis probability =   1.372523e-01
 
Photon flux (15-150 keV)    in 1 sec: 3.37293 ( -0.28658  0.28681 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.3267e-07 ( -2.20644e-08  2.22771e-08 ) ergs/cm2
    Cutoff power-law model
    Time interval is from   -0.196 sec. to    0.804 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.05344     ( -0.572383   0.653394 )
Epeak [keV] : 68.4196      ( -15.0139 98.8099 )
Norm@50keV  : 5.62287E-02    ( -0.0273744   0.064065 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          64.63 using 59 PHA bins.
# Reduced chi-squared =          1.154 for     56 degrees of freedom 
# Null hypothesis probability =   2.007335e-01
 
Photon flux (15-150 keV)    in 1 sec: 3.28812 ( -0.2967  0.29591 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.23254e-07 ( -2.33599e-08  2.36568e-08 ) ergs/cm2

    Time-resolved spectra




    Distribution

    T90 vs. Hardness ratio plot 

    T90                                   = 15.536 sec.
Hardness ratio (energy fluence ratio) = 0.975146774442

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

    S(15-50 keV)  = 5.441962e-07
S(50-150 keV) = 4.761908e-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 = 1.830738376657725E-02, IMY = -4.883774127948993E-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:
-239.760000 -7.044000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 95.6817  48.5338    3.3  48.8  157.8   2.6003   3.5 ------	UNKNOWN                       
156.8300 -28.6912    3.8  53.7   17.1   3.1284   3.0 ------	UNKNOWN                       
162.4127 -30.0494    2.5  55.9   11.5   5.7319   4.6 ------	UNKNOWN                       
170.2989 -28.9008    2.8  56.8    3.2   5.2528   4.1 ------	UNKNOWN                       
161.9509   5.8307    3.0  21.8   -8.1   0.7810   3.8 ------	UNKNOWN                       
121.5343  72.7392    3.0  50.6 -166.8   2.3017   3.9 ------	UNKNOWN                       
192.0700  32.0593    2.6  37.0  -87.3   3.0364   4.4 ------	UNKNOWN                       
193.4097  12.6243    3.3  42.2  -57.5   2.2499   3.5 ------	UNKNOWN                       
196.0616  61.8021    3.0  48.0 -129.2   3.8694   3.8 ------	UNKNOWN

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

    Time interval of the image:
-7.044000 10.868000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
126.8193  11.5362    0.4  26.0   87.9   1.9886  26.7 ------	UNKNOWN                       
181.8479  -8.2520    2.6  44.9  -22.9   0.3801   4.3 ------	UNKNOWN                       
195.8059  62.6788    2.7  48.3 -130.3   1.0000   4.3 ------	UNKNOWN

    Post-slew image of 15-350 keV band 

    Time interval of the image:
156.740600 842.290000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6245  22.0138    0.6  42.5  -47.7  20.6295  20.6    0.5	Crab                          
135.5746 -40.5385   11.0  52.8 -166.1   1.7224   1.0    2.3	Vela X-1                      
104.8270  65.4672    3.3  55.9   11.5  10.1950   3.5 ------	UNKNOWN                       
 88.9833  56.0860    3.0  53.2   -3.0   4.6589   3.8 ------	UNKNOWN