Analysis Summary

Notes:

Special note: Due to the low partial coding fraction, the refined position is found using the DETECTION mask. Therefore, the refined position and the mask shadow pattern shown here are from analyses with DETECTION mask, everything else uses the FLUX mask.

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.46
    Process Start Time: Sat May  9 19:14:39 EDT 2015
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger317508
======================================================================

  Trigger: 00317508      Segment: 000

  BAT Trigger Time: 238328719.936   [s; MET]
      Trigger Stop: 238328720.96   [s; MET]
               UTC: 2008-07-21T10:25:16.978500    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 224.47075880868   Dec: -11.7121266536717  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    10.24
     Image Trigger?:     NO
     Rate S/N Ratio:     142.337626789265  [ if not an image trigger ]
     Image S/N Ratio:    10.24

  Analysis Position:   [ source = BAT ]
    RA: 224.47075880868   Dec: -11.7121266536717  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA:    Dec:   [deg; J2000]  
        { 00h 00m 00.0s , +00d 00' 00.0" }
         +/- -inf [arcmin] (estimated 90% radius based on SNR)
         +/- 0 [arcmin] (formal 1-sigma fit error)
    SNR: 
 
  Angular difference between the analysis and refined position is -2740.388722 arcmin
 
  Partial Coding Fraction: 0.04394531    [ including projection effects ]

  Duration
     T90: 129.695999979973 +/- 114.470290030809
        Measured from: -8.08799999952316
                   to: 121.60799998045     [s; relative to TRIGTIME]
     T50: 6.89599996805191 +/- 0.780727867064375
        Measured from: -0.375999987125397
                   to: 6.51999998092651     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.148000001907349     
                   to: 0.851999998092651     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -10.2479999959469     
                   to: 360.136000007391     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     3.654342   6.048077   7.199913   3.491226
           0.260601   0.270167   0.264350   0.231941 [error]
 Peak      0.406318   0.668043   0.950865   0.544658
           0.048430   0.062307   0.071587   0.063550 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  370.384  -10.248  360.136
T90   129.696   -8.088  121.608
T50     6.896   -0.376    6.520
Peak    1.000   -0.148    0.852
 
 
====== 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      -1.125    -0.077      0.078       -           -               -         4.03e-03     -1.77e-04          1.77e-04      48.080   57
CPL     -1.120    -0.078      0.093     9998.140    -9998.140      -9998.140      4.05e-03     -1.75e-04          9.40e-04      48.100   56
 
 
=== 1-s peak spectral analysis ===
(Best model with acceptable fit: N/A)
 
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      -0.995     -0.145     0.148       -           -               -         1.78e-01     -1.52e-02          1.51e-02      62.790   57
CPL     -0.988     -0.147     0.541     9997.990    -9997.990      -9997.990      1.79e-01     -1.51e-02          1.18e-01      62.800   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   1.34e-06  3.10e-06  5.69e-06  2.49e-05  1.55e-05  3.51e-05   erg/cm2
      90%_error_low -1.27e-07 -1.77e-07 -2.52e-07 -2.53e-06 -6.58e-07 -2.61e-06   erg/cm2
      90%_error_hi   1.32e-07  1.76e-07  2.51e-07  2.73e-06  6.58e-07  2.77e-06   erg/cm2
Peak flux       PL   1.32e-03  1.49e-02  1.59e-01  1.25e+01  7.11e-01  1.26e+01   ph/cm2/s
      90%_error_low -5.92e-04 -5.91e-03 -5.73e-02 -3.66e+00 -2.51e-01 -3.71e+00   ph/cm2/s
      90%_error_hi   2.34e-03  2.29e-02  1.94e-01  9.63e+00  7.53e-01  9.86e+00   ph/cm2/s
 
Fluence        CPL   1.35e-06  3.10e-06  5.64e-06  2.53e-05  1.55e-05  3.44e-05   erg/cm2
      90%_error_low    N/A    -1.89e-07 -2.22e-07 -6.30e-06 -9.83e-07 -5.20e-06   erg/cm2
      90%_error_hi     N/A     1.79e-07  3.44e-07  8.72e-07  6.79e-07  3.23e-06   erg/cm2
Peak flux      CPL   4.58e+00  6.16e+00  6.17e+00  1.14e+01  2.05e+01  2.80e+01   ph/cm2/s
      90%_error_low     N/A   -6.36e-01 -5.32e-01 -5.24e+00 -1.85e+00 -4.64e+00   ph/cm2/s
      90%_error_hi      N/A    6.33e-01  3.68e-01  2.52e+00  1.82e+00  2.33e+00   ph/cm2/s
 
======================================================================
  • Special notes of this burst




    Image

    Pre-slew 15.0-350.0 keV image (Event data; DETECTION mask)

    #   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
      224.4774   -11.7086   0.0068    56.5228     3.2412        16.9051805     28.470 TRIG_00317508                 
     
    Foreground time interval of the image:
     -9.516  14.965 (delta_t =  24.481 [sec])
    Background time interval of the image:
    -677.935 -668.876 (delta_t =   9.059 [sec])
    -239.936  -9.516 (delta_t = 230.420 [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  -10.248 sec. to  360.136 sec.
     
    Spectral model in power-law:
    ------------------------------------------------------------
    Parameters  : value       lower 90%   higher 90%
    Photon index: -1.12523     ( -0.0774632   0.0783322 )
    Norm@50keV  : 4.02609E-03    ( -0.000177428   0.000176555 )
    ------------------------------------------------------------
    #Fit statistic : Chi-Squared =          48.08 using 59 PHA bins.
    # Reduced chi-squared =         0.8434 for     57 degrees of freedom 
    # Null hypothesis probability =   7.940528e-01
     
    Photon flux (15-150 keV)    in 370.4 sec: 0.468208 ( -0.022143  0.022244 ) ph/cm2/s
    Energy fluence (15-150 keV)             : 1.547e-05 ( -6.58108e-07  6.58375e-07 ) ergs/cm2
     
    
    Cutoff power-law model
    Time interval is from  -10.248 sec. to  360.136 sec.
    Spectral model in the cutoff power-law:
    ------------------------------------------------------------
    Parameters  : value       lower 90%   higher 90%
    Photon index: -1.11971     ( -0.0779692   0.09351 )
    Epeak [keV] : 9998.14      ( -9998.34 -9998.34 )
    Norm@50keV  : 4.04705E-03    ( -0.000175046   0.000940077 )
    ------------------------------------------------------------
    #Fit statistic : Chi-Squared =          48.10 using 59 PHA bins.
    # Reduced chi-squared =         0.8590 for     56 degrees of freedom 
    # Null hypothesis probability =   7.644274e-01
     
    Photon flux (15-150 keV)    in 370.4 sec: 0.470585 ( -0.026067  0.021686 ) ph/cm2/s
    Energy fluence (15-150 keV)             : 1.5495e-05 ( -9.82856e-07  6.7878e-07 ) ergs/cm2
     
    

    1-s peak spectrum fit

    Power-law model
    Time interval is from   -0.148 sec. to    0.852 sec.
     
    Spectral model in power-law:
    ------------------------------------------------------------
    Parameters  : value       lower 90%   higher 90%
    Photon index: -0.994738     ( -0.145464   0.147903 )
    Norm@50keV  : 0.177852    ( -0.0152289   0.0151367 )
    ------------------------------------------------------------
    #Fit statistic : Chi-Squared =          62.79 using 59 PHA bins.
    # Reduced chi-squared =          1.102 for     57 degrees of freedom 
    # Null hypothesis probability =   2.785973e-01
     
    Photon flux (15-150 keV)    in 1 sec: 0.711033 ( -0.250754  0.753297 ) ph/cm2/s
    Energy fluence (15-150 keV)             : 1.92699e-06 ( -1.69026e-07  1.69487e-07 ) ergs/cm2
     
    
    Cutoff power-law model
    Time interval is from   -0.148 sec. to    0.852 sec.
    Spectral model in the cutoff power-law:
    ------------------------------------------------------------
    Parameters  : value       lower 90%   higher 90%
    Photon index: -0.988401     ( -0.146791   0.540612 )
    Epeak [keV] : 9997.99      ( -9998.38 -9998.38 )
    Norm@50keV  : 0.178933    ( -0.0150578   0.118125 )
    ------------------------------------------------------------
    #Fit statistic : Chi-Squared =          62.80 using 59 PHA bins.
    # Reduced chi-squared =          1.121 for     56 degrees of freedom 
    # Null hypothesis probability =   2.480309e-01
     
    Photon flux (15-150 keV)    in 1 sec: 20.4876 ( -1.8471  1.817 ) ph/cm2/s
    Energy fluence (15-150 keV)             : 1.92832e-06 ( -1.92679e-07  1.40201e-07 ) ergs/cm2
     
    

    Time-resolved spectra




    Distribution

    T90 vs. Hardness ratio plot

    T90                                   = 129.696 sec.
    Hardness ratio (energy fluence ratio) = 1.83374977251
    

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

    S(15-50 keV)  = 4.446459e-06
    S(50-150 keV) = 1.1023405e-05
    

    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 (with DETECTION mask)

    IMX = 1.509720641894637E+00, IMY = -8.549460310624656E-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:
    -677.935400 -668.876000
    -239.936000 -10.248000
     
    # RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
    #  [deg]    [deg]    ['] [deg]  [deg]                   [']
    186.8652 -62.7994    7.6  35.0  -76.8   0.8042   1.5    6.0	GX 301-2                      
    244.9629 -15.6402    0.8  46.5   25.9   8.9276  15.1    1.0	Sco X-1                       
    255.9811 -37.8485    0.5  22.8   34.7   5.0467  22.8    0.4	4U 1700-377                   
    256.3410 -36.4517    3.7  24.1   36.1   0.7047   3.1    4.9	GX 349+2                      
    263.0255 -24.9221    0.0  35.1   50.0   0.4888   1.2   10.6	GX 1+4                        
    264.7037 -44.4669    4.2  15.5   53.0   0.5519   2.8    2.0	4U 1735-44                    
    270.3451 -25.0236    4.4  35.2   61.5   1.1598   2.6    4.7	GX 5-1                        
    270.0960 -25.8016    4.5  34.4   61.2  -1.0835  -2.5   11.7	GRS 1758-258                  
    275.8665 -30.3559    4.0  30.6   71.8   1.0912   2.8    3.1	H1820-303                     
    285.1613 -24.9186    6.0  37.9   83.7   1.3780   1.9    6.8	HT1900.1-2455                 
    262.9671 -33.6441    0.0  26.3   49.4   0.5271   1.9   11.5	GX 354-0                      
    305.2154 -47.6172    2.4  26.5  132.8   1.2985   4.9 ------	UNKNOWN                       
    231.2783 -27.0135    2.2  39.9    2.8   1.6837   5.2 ------	UNKNOWN                       
    191.6758 -36.4409    3.5  50.7  -44.6   4.2154   3.3 ------	UNKNOWN                       
    173.0729 -61.2859    2.6  41.1  -80.9   4.7605   4.5 ------	UNKNOWN                       
    

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

    Time interval of the image:
    -10.248000 14.964600
     
    # RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
    #  [deg]    [deg]    ['] [deg]  [deg]                   [']
    186.8312 -62.7795    4.5  35.0  -76.7   0.3570   2.6    4.8	GX 301-2                      
    244.8365 -15.6524    6.9  46.5   25.8  -0.4899  -1.7    8.3	Sco X-1                       
    255.8560 -37.9427   38.5  22.7   34.4  -0.0275  -0.3    8.6	4U 1700-377                   
    256.4457 -36.5399   27.0  24.0   36.3   0.0395   0.4    7.0	GX 349+2                      
    263.2446 -24.7191   11.2  35.3   50.3   0.1763   1.0   12.9	GX 1+4                        
    264.6888 -44.4711   13.4  15.5   52.9  -0.0765  -0.9    2.6	4U 1735-44                    
    270.3565 -25.0150    4.2  35.2   61.5  -0.5334  -2.8    5.5	GX 5-1                        
    270.1299 -25.7292    4.6  34.5   61.3  -0.4511  -2.5    9.4	GRS 1758-258                  
    275.9251 -30.3675  584.2  30.6   71.9   0.0029   0.0    0.0	H1820-303                     
    285.1955 -24.8908    6.3  37.9   83.7  -0.6330  -1.8    8.9	HT1900.1-2455                 
    262.7762 -33.8838   22.9  26.1   49.1  -0.0544  -0.5   11.0	GX 354-0                      
    257.7538 -11.9739    2.8  48.2   43.4   2.5605   4.1 ------	UNKNOWN                       
    252.7535 -46.2811    2.3  15.3   20.3   0.3827   5.0 ------	UNKNOWN                       
    224.4813 -11.7100    0.5  56.5    3.2  18.2891  21.7 ------	UNKNOWN                       
    190.7758 -38.1413    2.4  49.8  -46.7   1.4263   4.7 ------	UNKNOWN                       
    

    Post-slew image of 15-350 keV band

    Time interval of the image:
    96.364590 962.172500
     
    # RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
    #  [deg]    [deg]    ['] [deg]  [deg]                   [']
    186.6448 -62.7917   37.9  57.6 -178.5   1.0580   0.3    1.3	GX 301-2                      
    244.9756 -15.6412    0.2  20.3   85.4  40.9608  54.1    0.2	Sco X-1                       
    254.4427  35.5197    6.3  55.1   11.8  -5.1380  -1.8   10.7	Her X-1                       
    256.0207 -37.8131    1.5  38.4  120.3  14.9629   7.8    2.5	4U 1700-377                   
    256.4030 -36.4510    6.0  37.9  118.2   3.6001   1.9    2.3	GX 349+2                      
    263.0096 -24.7459   35.4  38.7   97.2   0.7028   0.3    0.0	GX 1+4                        
    265.3601  -1.4376    2.9  41.8   60.9   9.5776   4.0 ------	UNKNOWN                       
    242.7188 -19.5134    2.9  19.2   98.1   2.7638   4.0 ------	UNKNOWN                       
    248.5583  35.3279    2.2  52.3    7.0   9.2183   5.2 ------	UNKNOWN                       
    234.3733  44.9999    3.8  57.5   -9.6   9.1353   3.0 ------	UNKNOWN                       
    199.9721  33.2718    3.7  50.7  -44.5  13.1489   3.1 ------	UNKNOWN