Analysis Summary

Notes:

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.46
    Process Start Time: Mon Sep 11 17:20:59 EDT 2017
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger766081
======================================================================

  Trigger: 00766081      Segment: 000

  BAT Trigger Time: 523474246.644   [s; MET]
      Trigger Stop: 523474246.708   [s; MET]
               UTC: 2017-08-03T17:30:27.173280    [includes UTCF correction] 
       Where From?: (*SHORT BURST*) TDRSS scaled map message

  BAT 
    RA: 174.949880933376   Dec: -16.3107712626632  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    10.73
     Image Trigger?:     NO
     Rate S/N Ratio:     32.6036807738022  [ if not an image trigger ]
     Image S/N Ratio:    10.73

  Analysis Position:   [ source = BAT ]
    RA: 174.949880933376   Dec: -16.3107712626632  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 174.947690607081   Dec: -16.3112304817445  [deg; J2000]  
        { 11h 39m 47.4s , -16d 18' 40.4" }
         +/- 0.769239298439966 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.264968731410357 [arcmin] (formal 1-sigma fit error)
    SNR: 44.2473961266501
 
  Angular difference between the analysis and refined position is 0.129105 arcmin
 
  Partial Coding Fraction: 0.9453125    [ including projection effects ]

  Duration
     T90: 3.81999999284744 +/- 0.236812129310609
        Measured from: -0.188000023365021
                   to: 3.63199996948242     [s; relative to TRIGTIME]
     T50: 1.61199992895126 +/- 0.0809938026694786
        Measured from: 0.216000020503998
                   to: 1.82799994945526     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.11599999666214     
                   to: 0.88400000333786     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.691999971866608     
                   to: 4.14399999380112     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.351271   0.572649   0.526022   0.116623
           0.015775   0.017379   0.015858   0.011834 [error]
 Peak      0.153312   0.286924   0.303703   0.082181
           0.008281   0.010035   0.010110   0.006809 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100    4.836   -0.692    4.144
T90     3.820   -0.188    3.632
T50     1.612    0.216    1.828
Peak    1.000   -0.116    0.884
 
 
====== 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: 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      -1.306    -0.060      0.060       -           -               -         2.22e-02     -7.55e-04          7.55e-04      55.070   57
CPL     -0.749    -0.256      0.271      126.124     -23.965        58.118      3.96e-02     -9.03e-03          1.25e-02      40.420   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      -1.102     -0.064     0.064       -           -               -         5.62e-02     -2.12e-03          2.12e-03      68.270   57
CPL     -0.564     -0.259     0.275      153.929     -33.311        85.770      9.77e-02     -2.22e-02          3.05e-02      54.910   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   1.14e-07  2.37e-07  3.83e-07  1.39e-06  1.06e-06  2.12e-06   erg/cm2
      90%_error_low -7.53e-09 -9.38e-09 -1.54e-08 -1.22e-07 -3.87e-08 -1.32e-07   erg/cm2
      90%_error_hi   7.71e-09  9.34e-09  1.54e-08  1.30e-07  3.88e-08  1.38e-07   erg/cm2
Peak flux       PL   4.30e-04  6.94e-03  8.08e-02  6.69e+00  3.53e-01  4.17e+00   ph/cm2/s
      90%_error_low     N/A       N/A       N/A       N/A       N/A       N/A     ph/cm2/s
      90%_error_hi      N/A       N/A       N/A       N/A       N/A       N/A     ph/cm2/s
 
Fluence        CPL   9.97e-08  2.45e-07  4.03e-07  7.15e-07  1.03e-06  1.46e-06   erg/cm2
      90%_error_low -9.57e-09 -1.04e-08 -1.82e-08 -1.71e-07 -4.18e-08 -1.73e-07   erg/cm2
      90%_error_hi   9.81e-09  1.05e-08  1.84e-08  2.39e-07  4.17e-08  2.37e-07   erg/cm2
Peak flux      CPL   1.38e+00  2.08e+00  2.01e+00  1.90e+00  6.40e+00  7.36e+00   ph/cm2/s
      90%_error_low -1.46e-01 -1.01e-01 -9.96e-02 -3.72e-01 -2.60e-01 -4.59e-01   ph/cm2/s
      90%_error_hi   1.49e-01  1.01e-01  1.01e-01  4.83e-01  2.60e-01  5.38e-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
  174.9477   -16.3112   0.0043    26.2826    -9.7529         1.5687024     44.247 TRIG_00766081                 
 
Foreground time interval of the image:
 -0.692   4.144 (delta_t =   4.836 [sec])
Background time interval of the image:
-18.943  -0.692 (delta_t =  18.251 [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   -0.692 sec. to    4.144 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.30595     ( -0.0603959   0.0604793 )
Norm@50keV  : 2.22008E-02    ( -0.000754764   0.000754738 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          55.07 using 59 PHA bins.
# Reduced chi-squared =         0.9661 for     57 degrees of freedom 
# Null hypothesis probability =   5.479774e-01
 
Photon flux (15-150 keV)    in 4.836 sec: 2.65156 ( -0.09573  0.09592 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.05954e-06 ( -3.87253e-08  3.88001e-08 ) ergs/cm2
    Cutoff power-law model
    Time interval is from   -0.692 sec. to    4.144 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.749432     ( -0.255998   0.271344 )
Epeak [keV] : 126.124      ( -23.965 58.1178 )
Norm@50keV  : 3.95934E-02    ( -0.00902869   0.0124586 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          40.42 using 59 PHA bins.
# Reduced chi-squared =         0.7217 for     56 degrees of freedom 
# Null hypothesis probability =   9.420539e-01
 
Photon flux (15-150 keV)    in 4.836 sec: 2.56941 ( -0.10187  0.10222 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.02867e-06 ( -4.1786e-08  4.16561e-08 ) ergs/cm2

    1-s peak spectrum fit

    Power-law model
    Time interval is from   -0.116 sec. to    0.884 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.10246     ( -0.063535   0.0638076 )
Norm@50keV  : 5.62419E-02    ( -0.0021199   0.00211917 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          68.27 using 59 PHA bins.
# Reduced chi-squared =          1.198 for     57 degrees of freedom 
# Null hypothesis probability =   1.458889e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.353026 (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 5.87625e-07 ( -2.40782e-08  2.41194e-08 ) ergs/cm2
    Cutoff power-law model
    Time interval is from   -0.116 sec. to    0.884 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.564481     ( -0.259274   0.275325 )
Epeak [keV] : 153.929      ( -33.3107 85.7706 )
Norm@50keV  : 9.76673E-02    ( -0.0222018   0.0305329 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          54.91 using 59 PHA bins.
# Reduced chi-squared =         0.9805 for     56 degrees of freedom 
# Null hypothesis probability =   5.162968e-01
 
Photon flux (15-150 keV)    in 1 sec: 6.39582 ( -0.25979  0.25997 ) ph/cm2/s
Energy fluence (15-150 keV)             : 5.76116e-07 ( -2.52068e-08  2.51408e-08 ) ergs/cm2

    Time-resolved spectra




    Distribution

    T90 vs. Hardness ratio plot 

    T90                                   = 3.82 sec.
Hardness ratio (energy fluence ratio) = 1.64729005701

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

    S(15-50 keV)  = 3.446038e-07
S(50-150 keV) = 6.840778e-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 = 4.867149743435846E-01, IMY = 8.365845143776025E-02

    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:
-18.943400 -0.692000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.5248 -40.5479    1.7  16.6  143.3   0.3124   6.8    0.4	Vela X-1                      
170.2076 -60.7824   31.7  35.0   85.4  -0.0381  -0.4   10.1	Cen X-3                       
109.9137 -58.6767    2.4  40.5  133.5   0.5604   4.7 ------	UNKNOWN

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

    Time interval of the image:
-0.692000 4.144000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.7032 -40.4002    0.0  16.4  143.4  -0.0334  -1.0   12.2	Vela X-1                      
170.4576 -60.7558    5.7  35.0   85.2   0.1582   2.0    9.0	Cen X-3                       
192.0862 -28.6945    2.3  37.0   23.4   0.2544   5.0 ------	UNKNOWN                       
154.4171 -41.7434    1.9  13.7   87.8   0.2157   6.1 ------	UNKNOWN                       
174.9477 -16.3112    0.3  26.3   -9.8   1.5683  44.2 ------	UNKNOWN

    Post-slew image of 15-350 keV band 

    Time interval of the image:
67.656580 782.446000
840.356000 902.435600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.5627 -40.5490    2.6  41.7 -171.4   4.2273   4.5    1.6	Vela X-1                      
170.0124 -60.5872    9.2  44.4  145.7   2.2362   1.2    9.2	Cen X-3                       
186.5633 -62.8276    2.0  47.2  135.0  14.6883   5.7    4.3	GX 301-2                      
203.0259 -17.0297    3.0  26.9   57.8   3.0261   3.8 ------	UNKNOWN                       
203.0472  17.1520    2.3  43.4    3.1   4.6253   5.0 ------	UNKNOWN                       
124.1928 -13.4526    2.7  49.0 -131.7  12.1631   4.3 ------	UNKNOWN