Analysis Summary

Notes:

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.46
    Process Start Time: Sun May 17 01:32:26 EDT 2015
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger638946
======================================================================

  Trigger: 00638946      Segment: 000

  BAT Trigger Time: 451554190.564   [s; MET]
      Trigger Stop: 451554190.628   [s; MET]
               UTC: 2015-04-24T07:42:57.075440    [includes UTCF correction] 
       Where From?: (*SHORT BURST*) TDRSS scaled map message

  BAT 
    RA: 152.312128050396   Dec: -26.6466164433475  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    15.22
     Image Trigger?:     NO
     Rate S/N Ratio:     250.966133173383  [ if not an image trigger ]
     Image S/N Ratio:    15.22

  Analysis Position:   [ source = BAT ]
    RA: 152.312128050396   Dec: -26.6466164433475  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 152.305235855337   Dec: -26.6473550660799  [deg; J2000]  
        { 10h 09m 13.3s , -26d 38' 50.5" }
         +/- 0.895851674156214 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.269648104699712 [arcmin] (formal 1-sigma fit error)
    SNR: 35.5920095349208
 
  Angular difference between the analysis and refined position is 0.372257 arcmin
 
  Partial Coding Fraction: 0.6953125    [ including projection effects ]

  Duration
     T90: 81.055999994278 +/- 17.4800292500718
        Measured from: -0.0279999971389771
                   to: 81.027999997139     [s; relative to TRIGTIME]
     T50: 12.7520000338554 +/- 18.3920277981243
        Measured from: 0.0839999914169312
                   to: 12.8360000252724     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.0720000267028809     
                   to: 0.927999973297119     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.0600000023841858     
                   to: 95.0119999647141     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.431852   0.685924   0.762470   0.309109
           0.059178   0.061578   0.054463   0.046555 [error]
 Peak      0.244502   0.452358   0.620572   0.279085
           0.011892   0.015366   0.017930   0.015690 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   95.072   -0.060   95.012
T90    81.056   -0.028   81.028
T50    12.752    0.084   12.836
Peak    1.000   -0.072    0.928
 
 
====== 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      -1.172    -0.149      0.153       -           -               -         1.54e-03     -1.27e-04          1.26e-04      61.850   57
CPL     -1.122    -0.202      0.335      983.671    -983.671      -983.671      1.62e-03     -2.02e-04          4.99e-05      62.140   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      -0.803     -0.062     0.062       -           -               -         1.05e-01     -3.68e-03          3.66e-03      49.540   57
CPL     -0.795     -0.063     0.263     9950.560    -9950.560      -9950.560      1.06e-01     -3.64e-03          2.97e-02      49.530   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   1.37e-07  3.09e-07  5.49e-07  2.29e-06  1.50e-06  3.29e-06   erg/cm2
      90%_error_low -2.29e-08 -3.12e-08 -5.18e-08 -4.64e-07 -1.31e-07 -4.95e-07   erg/cm2
      90%_error_hi   2.41e-08  3.06e-08  5.12e-08  5.46e-07  1.32e-07  5.63e-07   erg/cm2
Peak flux       PL   2.22e+00  3.40e+00  3.90e+00  8.55e+00  1.21e+01  1.81e+01   ph/cm2/s
      90%_error_low -1.67e-01 -1.55e-01 -1.39e-01 -6.73e-01 -4.15e-01 -7.30e-01   ph/cm2/s
      90%_error_hi   1.72e-01  1.55e-01  1.39e-01  7.10e-01  4.15e-01  7.45e-01   ph/cm2/s
 
Fluence        CPL   1.37e-07  3.07e-07  5.43e-07  2.44e-06  1.50e-06  3.12e-06   erg/cm2
      90%_error_low    N/A    -3.70e-08 -5.96e-08 -1.04e-06 -1.69e-07 -7.66e-07   erg/cm2
      90%_error_hi     N/A     3.96e-08  7.13e-08  8.30e-08  1.59e-07  7.12e-07   erg/cm2
Peak flux      CPL   2.18e+00  3.40e+00  8.25e-03  7.69e+00  6.65e-02  7.77e+00   ph/cm2/s
      90%_error_low -2.00e-01 -1.41e-01 -8.25e-03 -4.23e+00 -6.65e-02 8.19e+00   ph/cm2/s
      90%_error_hi   1.77e-01  1.27e-01  2.24e-02  3.78e+00  8.28e-02  1.06e+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
  152.3052   -26.6474   0.0054    34.0680  -175.1568         1.7368904     35.592 TRIG_00638946                 
 
Foreground time interval of the image:
 -0.060   9.137 (delta_t =   9.197 [sec])
Background time interval of the image:
-239.564  -0.060 (delta_t = 239.504 [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   -0.060 sec. to   95.012 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.17156     ( -0.149173   0.152602 )
Norm@50keV  : 1.53899E-03    ( -0.000126803   0.000126385 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          61.85 using 59 PHA bins.
# Reduced chi-squared =          1.085 for     57 degrees of freedom 
# Null hypothesis probability =   3.070241e-01
 
Photon flux (15-150 keV)    in 95.07 sec: 0.179957 ( -0.015571  0.01566 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.49676e-06 ( -1.31414e-07  1.32059e-07 ) ergs/cm2
    Cutoff power-law model
    Time interval is from   -0.060 sec. to   95.012 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.16699     ( -0.202064   0.334844 )
Epeak [keV] : 1.00000E+04      ( -10000 -10000 )
Norm@50keV  : 1.54658E-03    ( -0.000126215   0.000126035 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          61.88 using 59 PHA bins.
# Reduced chi-squared =          1.105 for     56 degrees of freedom 
# Null hypothesis probability =   2.743960e-01
 
Photon flux (15-150 keV)    in 95.07 sec: 0.180834 ( -0.017288  0.018823 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.50226e-06 ( -1.69462e-07  1.59331e-07 ) ergs/cm2

    1-s peak spectrum fit

    Power-law model
    Time interval is from   -0.072 sec. to    0.928 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.802818     ( -0.0617769   0.062327 )
Norm@50keV  : 0.104953    ( -0.00368044   0.00366314 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          49.54 using 59 PHA bins.
# Reduced chi-squared =         0.8691 for     57 degrees of freedom 
# Null hypothesis probability =   7.481738e-01
 
Photon flux (15-150 keV)    in 1 sec: 12.0611 ( -0.415  0.4153 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.22512e-06 ( -4.55601e-08  4.56589e-08 ) ergs/cm2
    Cutoff power-law model
    Time interval is from   -0.072 sec. to    0.928 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.795095     ( -0.0625724   0.263483 )
Epeak [keV] : 9950.56      ( -9892.71 -9892.71 )
Norm@50keV  : 0.105703    ( -0.0036492   0.0296862 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          49.53 using 59 PHA bins.
# Reduced chi-squared =         0.8844 for     56 degrees of freedom 
# Null hypothesis probability =   7.167909e-01
 
Photon flux (15-150 keV)    in 1 sec: 6.64938E-02 ( -0.0664938  0.0827652 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.66827e-08 ( 0  0 ) ergs/cm2

    Time-resolved spectra




    Distribution

    T90 vs. Hardness ratio plot 

    T90                                   = 81.056 sec.
Hardness ratio (energy fluence ratio) = 1.7758650315

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

    S(15-50 keV)  = 4.464912e-07
S(50-150 keV) = 1.0502676e-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 = -6.738218905893313E-01, IMY = 5.709394877316486E-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:
-239.564000 -0.060000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.5888 -40.6384    5.1  53.7 -175.0   1.4619   2.3    5.7	Vela X-1                      
201.3187 -30.4920    3.9  41.0  111.8   2.4750   2.9 ------	UNKNOWN                       
121.7342 -32.1863    3.5  58.8 -159.3   4.8241   3.3 ------	UNKNOWN                       
189.6613  58.5217    2.3  59.2  -20.4   6.2319   4.9 ------	UNKNOWN                       
130.4924 -16.6153    2.6  45.7 -144.5   1.8881   4.4 ------	UNKNOWN                       
147.0256  31.9921    3.1  40.0  -66.1   2.1285   3.7 ------	UNKNOWN                       
129.5737   3.0681    2.7  43.8 -116.5   3.5777   4.3 ------	UNKNOWN

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

    Time interval of the image:
-0.060000 9.136600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.4894 -40.4525    8.2  53.7 -174.7   0.1706   1.4    6.4	Vela X-1                      
152.3052 -26.6474    0.3  34.1 -175.2   1.7369  35.6 ------	UNKNOWN                       
131.1279 -37.3112    2.4  54.5 -169.1   0.6473   4.9 ------	UNKNOWN                       
176.6153  52.2707    2.0  51.6  -27.7   0.6781   5.9 ------	UNKNOWN

    Post-slew image of 15-350 keV band 

    Time interval of the image:
75.536620 962.566000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.5272 -40.5526    1.7  19.7 -137.4   3.9709   6.8    0.1	Vela X-1                      
170.3862 -60.6351    4.4  36.2  167.0   2.2742   2.6    2.2	Cen X-3                       
186.6944 -62.7769    0.8  42.6  159.5  17.8632  13.7    1.1	GX 301-2                      
175.5856  19.0359    3.9  50.9   30.7   8.4977   3.0 ------	UNKNOWN                       
161.1524 -44.2019    2.8  19.0  162.1   2.2895   4.2 ------	UNKNOWN                       
101.4962 -38.0470    3.9  43.9 -116.3   7.7909   3.0 ------	UNKNOWN