Analysis Summary

Notes:

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.46
    Process Start Time: Mon Jan 20 09:52:50 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger278903
======================================================================

  Trigger: 00278903      Segment: 000

  BAT Trigger Time: 200371709.248   [s; MET]
      Trigger Stop: 200371710.272   [s; MET]
               UTC: 2007-05-09T02:48:27.305440    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 237.926549002769   Dec: -78.6806906520622  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    8.66
     Image Trigger?:     NO
     Rate S/N Ratio:     13.6014705087354  [ if not an image trigger ]
     Image S/N Ratio:    8.66

  Analysis Position:   [ source = BAT ]
    RA: 237.926549002769   Dec: -78.6806906520622  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 237.898683721382   Dec: -78.6530361224751  [deg; J2000]  
        { 15h 51m 35.7s , -78d 39' 10.9" }
         +/- 1.68055177092417 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.630720767832941 [arcmin] (formal 1-sigma fit error)
    SNR: 14.4891945239721
 
  Angular difference between the analysis and refined position is 1.691488 arcmin
 
  Partial Coding Fraction: 0.9296875    [ including projection effects ]

  Duration
     T90: 7.82800000905991 +/- 1.16132337087018
        Measured from: -1.05199998617172
                   to: 6.77600002288818     [s; relative to TRIGTIME]
     T50: 3.53599998354912 +/- 1.10314461654296
        Measured from: 0.0520000159740448
                   to: 3.58799999952316     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.30799999833107     
                   to: 0.69200000166893     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -1.43199998140335     
                   to: 7.86800000071526     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.175647   0.157118   0.062505   0.008759
           0.015121   0.015196   0.012920   0.011052 [error]
 Peak      0.023791   0.037870   0.022231   0.004316
           0.005110   0.005290   0.004378   0.003679 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100    9.300   -1.432    7.868
T90     7.828   -1.052    6.776
T50     3.536    0.052    3.588
Peak    1.000   -0.308    0.692
 
 
====== 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      -2.209    -0.235      0.218       -           -               -         2.14e-03     -3.51e-04          3.44e-04      54.850   57
CPL     -1.955    -0.026      1.224        6.572      -6.159        -6.572      3.10e-03        N/A               N/A         54.410   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      -1.593     -0.291     0.281       -           -               -         5.28e-03     -9.76e-04          9.61e-04      65.410   57
CPL     -0.180     -1.277     1.851       61.173     -14.739       109.508      2.90e-02     -2.90e-02          2.31e-01      61.740   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   4.97e-08  5.95e-08  5.15e-08  7.61e-08  1.88e-07  2.37e-07   erg/cm2
      90%_error_low -7.08e-09 -6.97e-09 -1.12e-08 -2.79e-08 -2.58e-08 -4.34e-08   erg/cm2
      90%_error_hi   7.18e-09  6.88e-09  1.18e-08  3.75e-08  2.67e-08  5.09e-08   erg/cm2
Peak flux       PL   2.37e-01  2.26e-01  1.50e-01  1.55e-01  6.76e-01  7.68e-01   ph/cm2/s
      90%_error_low -6.12e-02 -3.98e-02 -3.47e-02 -6.05e-02 -1.16e-01 -1.34e-01   ph/cm2/s
      90%_error_hi   6.52e-02  3.96e-02  3.47e-02  7.99e-02  1.17e-01  1.36e-01   ph/cm2/s
 
Fluence        CPL   4.90e-08  6.19e-08  4.89e-08  3.60e-08  1.79e-07  1.96e-07   erg/cm2
      90%_error_low    N/A       N/A    -1.60e-08 -3.08e-08 -3.16e-08    N/A      erg/cm2
      90%_error_hi     N/A       N/A     1.34e-08  7.09e-08  3.15e-08    N/A      erg/cm2
Peak flux      CPL   1.90e-01  2.59e-01  1.61e-01  4.18e-02  6.43e-01  6.52e-01   ph/cm2/s
      90%_error_low -7.56e-02 -5.05e-02 -4.15e-02 -4.18e-02 -1.21e-01 -1.28e-01   ph/cm2/s
      90%_error_hi   7.83e-02  5.39e-02  4.17e-02  9.41e-02  1.21e-01  1.40e-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
  237.8987   -78.6530   0.0133    13.9036    47.3059         0.4054500     14.489 TRIG_00278903                 
 
Foreground time interval of the image:
 -1.432   7.868 (delta_t =   9.300 [sec])
Background time interval of the image:
-239.248  -1.432 (delta_t = 237.816 [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   -1.432 sec. to    7.868 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.20852     ( -0.234555   0.217997 )
Norm@50keV  : 2.14152E-03    ( -0.000351314   0.000344452 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          54.85 using 59 PHA bins.
# Reduced chi-squared =         0.9623 for     57 degrees of freedom 
# Null hypothesis probability =   5.561505e-01
 
Photon flux (15-150 keV)    in 9.3 sec: 0.356166 ( -0.038782  0.038783 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.87518e-07 ( -2.58204e-08  2.66889e-08 ) ergs/cm2
    Cutoff power-law model
    Time interval is from   -1.432 sec. to    7.868 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.95455     ( -0.0384601   1.21206 )
Epeak [keV] : 6.57208      ( -9.35212 -9.76543 )
Norm@50keV  : 3.09796E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          54.40 using 59 PHA bins.
# Reduced chi-squared =         0.9715 for     56 degrees of freedom 
# Null hypothesis probability =   5.355605e-01
 
Photon flux (15-150 keV)    in 9.3 sec: 0.351756 ( -0.040145  0.039363 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.78983e-07 ( -3.16424e-08  3.14979e-08 ) ergs/cm2

    1-s peak spectrum fit

    Power-law model
    Time interval is from   -0.308 sec. to    0.692 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.59257     ( -0.290974   0.280953 )
Norm@50keV  : 5.27581E-03    ( -0.00097606   0.000960949 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          65.41 using 59 PHA bins.
# Reduced chi-squared =          1.147 for     57 degrees of freedom 
# Null hypothesis probability =   2.079802e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.676436 ( -0.116495  0.1166 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.93924e-08 ( -9.68788e-09  9.89877e-09 ) ergs/cm2
    Cutoff power-law model
    Time interval is from   -0.308 sec. to    0.692 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.179929     ( -1.27744   1.85094 )
Epeak [keV] : 61.1733      ( -14.7376 109.509 )
Norm@50keV  : 2.89698E-02    ( -0.028988   0.230638 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          61.74 using 59 PHA bins.
# Reduced chi-squared =          1.103 for     56 degrees of freedom 
# Null hypothesis probability =   2.784117e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.642935 ( -0.121421  0.12094 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.47775e-08 ( -9.78459e-09  1.05652e-08 ) ergs/cm2

    Time-resolved spectra




    Distribution

    T90 vs. Hardness ratio plot 

    T90                                   = 7.828 sec.
Hardness ratio (energy fluence ratio) = 0.865485959598

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

    S(15-50 keV)  = 1.0918648e-07
S(50-150 keV) = 7.833374e-08

    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 = 1.678535513484074E-01, IMY = -1.819385232035663E-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:
-239.248000 -1.432000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
170.3734 -60.6387   29.7  39.1   23.3   0.1095   0.4    1.9	Cen X-3                       
186.7613 -62.7889    3.1  35.2   34.9   0.9350   3.7    3.1	GX 301-2                      
264.9704 -44.5019  154.1  38.5  116.8   0.0336   0.1   10.2	4U 1735-44                    
280.5538 -34.9891    2.3  45.5  137.2   2.9659   5.0 ------	UNKNOWN                       
329.8789 -19.9327    2.8  59.0 -166.2   4.5616   4.2 ------	UNKNOWN                       
 85.8220 -47.7589    2.5  50.7  -44.4   4.2694   4.5 ------	UNKNOWN                       
 13.3308 -41.8079    2.8  43.4 -114.1   3.2197   4.0 ------	UNKNOWN

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

    Time interval of the image:
-1.432000 7.868000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
170.2062 -60.7490    3.7  39.1   23.1  -0.1514  -3.1    8.2	Cen X-3                       
186.6087 -62.6739    6.2  35.3   34.9   0.0880   1.9    5.9	GX 301-2                      
264.6636 -44.5018    9.7  38.5  116.5   0.1013   1.2    4.6	4U 1735-44                    
252.5674 -53.5192    2.6  32.1   98.9   0.2199   4.4 ------	UNKNOWN                       
299.8430 -26.0391    2.4  52.7  160.4   0.5969   4.7 ------	UNKNOWN                       
237.8987 -78.6530    0.8  13.9   47.3   0.4054  14.5 ------	UNKNOWN                       
327.1704 -20.8920    2.3  57.9 -169.1   0.7215   5.1 ------	UNKNOWN

    Post-slew image of 15-350 keV band 

    Time interval of the image:
52.252600 962.834000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.6268 -40.3915    5.0  52.9   -7.7  -2.9523  -2.3   10.8	Vela X-1                      
170.2972 -60.6246    2.6  27.0   14.9   2.1897   4.3    0.6	Cen X-3                       
186.6806 -62.7816    1.0  21.8   29.9   5.6952  11.9    0.9	GX 301-2                      
256.0483 -37.7072   63.7  41.7  125.1   0.3146   0.2    8.7	4U 1700-377                   
256.4087 -36.3451    4.1  43.0  125.3   5.6784   2.8    4.8	GX 349+2                      
264.7283 -44.4617   41.4  35.7  136.8   0.2617   0.3    0.9	4U 1735-44                    
275.9226 -30.4950   26.3  50.9  146.5   1.1221   0.4    7.7	H1820-303                     
263.0346 -33.9111    4.2  46.0  132.6   5.5466   2.8    5.1	GX 354-0