Analysis Summary

Notes:

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.46
    Process Start Time: Sun Jan 19 19:44:23 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger338177
======================================================================

  Trigger: 00338177      Segment: 000

  BAT Trigger Time: 251946220.736   [s; MET]
      Trigger Stop: 251946220.992   [s; MET]
               UTC: 2008-12-26T01:03:37.372040    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 120.526759597338   Dec: -69.0057732552917  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.6
     Image Trigger?:     NO
     Rate S/N Ratio:     19.9749843554382  [ if not an image trigger ]
     Image S/N Ratio:    7.6

  Analysis Position:   [ source = BAT ]
    RA: 120.526759597338   Dec: -69.0057732552917  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 120.483039862506   Dec: -69.0159725121132  [deg; J2000]  
        { 08h 01m 55.9s , -69d 00' 57.5" }
         +/- 2.12670613782388 [arcmin] (estimated 90% radius based on SNR)
         +/- 1.17900972090809 [arcmin] (formal 1-sigma fit error)
    SNR: 10.3505834402121
 
  Angular difference between the analysis and refined position is 1.121311 arcmin
 
  Partial Coding Fraction: 0.328125    [ including projection effects ]

  Duration
     T90: 0.435999989509583 +/- 0.075153169006516
        Measured from: -0.0279999971389771
                   to: 0.407999992370605     [s; relative to TRIGTIME]
     T50: 0.196000009775162 +/- 0.0948261490152567
        Measured from: 0.0439999997615814
                   to: 0.240000009536743     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.300000011920929     
                   to: 0.699999988079071     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.0520000159740448     
                   to: 0.451999992132187     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.031160   0.040306   0.051488   0.033053
           0.007205   0.007965   0.007746   0.006579 [error]
 Peak      0.026473   0.034637   0.054571   0.043159
           0.009711   0.010435   0.009537   0.008335 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100    0.504   -0.052    0.452
T90     0.436   -0.028    0.408
T50     0.196    0.044    0.240
Peak    1.000   -0.300    0.700
 
 
====== 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      -1.414    -0.310      0.307       -           -               -         1.88e-02     -3.37e-03          3.36e-03      69.980   57
CPL     -1.213    -1.605      1.276      210.055    -210.055      -210.055      2.34e-02     -7.92e-03          6.81e-02      69.870   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      -1.028     -0.408     0.457       -           -               -         9.35e-03     -2.33e-03          2.24e-03      67.440   57
CPL     -1.021     -5.563     1.709     9991.660    -9991.660      -9991.660      9.41e-03     -2.16e-03          4.16e-02      67.440   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   1.11e-08  2.16e-08  3.24e-08  1.05e-07  9.11e-08  1.70e-07   erg/cm2
      90%_error_low -3.35e-09 -4.21e-09 -7.31e-09 -4.32e-08 -1.78e-08 -4.99e-08   erg/cm2
      90%_error_hi   3.64e-09  4.12e-09  7.15e-09  5.90e-08  1.79e-08  6.25e-08   erg/cm2
Peak flux       PL   2.45e-01  3.27e-01  3.21e-01  5.64e-01  1.08e+00  1.46e+00   ph/cm2/s
      90%_error_low -1.17e-01 -1.08e-01 -7.58e-02 -2.46e-01 -2.71e-01 -3.38e-01   ph/cm2/s
      90%_error_hi   1.42e-01  1.04e-01  7.49e-02  3.57e-01  2.75e-01  3.48e-01   ph/cm2/s
 
Fluence        CPL   1.07e-08  2.20e-08  3.31e-08  7.94e-08  9.03e-08  1.45e-07   erg/cm2
      90%_error_low -4.04e-09 -4.54e-09 -7.85e-09 -5.97e-08 -1.86e-08 -6.32e-08   erg/cm2
      90%_error_hi   3.60e-09  4.92e-09  8.39e-09  3.76e-08  1.84e-08  4.26e-08   erg/cm2
Peak flux      CPL   2.57e-01  3.27e-01  3.20e-01  5.78e-01  1.08e+00  1.47e+00   ph/cm2/s
      90%_error_low -1.56e-01 -9.24e-02 -7.52e-02     N/A   -2.75e-01 -5.57e-01   ph/cm2/s
      90%_error_hi   1.19e-01  1.09e-01  9.69e-02     N/A    2.73e-01  3.30e-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
  120.4830   -69.0160   0.0186    47.2667  -159.1419         0.1620785     10.351 TRIG_00338177                 
 
Foreground time interval of the image:
 -0.052   0.452 (delta_t =   0.504 [sec])
Background time interval of the image:
-239.736  -0.052 (delta_t = 239.684 [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   -0.052 sec. to    0.452 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.41444     ( -0.309796   0.306767 )
Norm@50keV  : 1.87511E-02    ( -0.00337048   0.00335884 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          69.98 using 59 PHA bins.
# Reduced chi-squared =          1.228 for     57 degrees of freedom 
# Null hypothesis probability =   1.159956e-01
 
Photon flux (15-150 keV)    in 0.504 sec: 2.29117 ( -0.42093  0.42261 ) ph/cm2/s
Energy fluence (15-150 keV)             : 9.10627e-08 ( -1.77903e-08  1.79433e-08 ) ergs/cm2
    Cutoff power-law model
    Time interval is from   -0.052 sec. to    0.452 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.21263     ( -1.60531   1.27575 )
Epeak [keV] : 210.055      ( -209.658 -209.658 )
Norm@50keV  : 2.34481E-02    ( -0.00793699   0.068098 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          69.87 using 59 PHA bins.
# Reduced chi-squared =          1.248 for     56 degrees of freedom 
# Null hypothesis probability =   1.006747e-01
 
Photon flux (15-150 keV)    in 0.504 sec: 2.27440 ( -0.4307  0.43052 ) ph/cm2/s
Energy fluence (15-150 keV)             : 9.02694e-08 ( -1.85593e-08  1.83933e-08 ) ergs/cm2

    1-s peak spectrum fit

    Power-law model
    Time interval is from   -0.300 sec. to    0.700 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.02822     ( -0.407785   0.457233 )
Norm@50keV  : 9.35324E-03    ( -0.00232546   0.00224096 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          67.44 using 59 PHA bins.
# Reduced chi-squared =          1.183 for     57 degrees of freedom 
# Null hypothesis probability =   1.623204e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.07862 ( -0.270587  0.27478 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.00159e-07 ( -2.34158e-08  2.34642e-08 ) ergs/cm2
    Cutoff power-law model
    Time interval is from   -0.300 sec. to    0.700 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.0214     ( -5.56251   1.70892 )
Epeak [keV] : 9991.66      ( -9996.11 -9996.11 )
Norm@50keV  : 9.41482E-03    ( -0.00215496   0.0416316 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          67.44 using 59 PHA bins.
# Reduced chi-squared =          1.204 for     56 degrees of freedom 
# Null hypothesis probability =   1.407734e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.08043 ( -0.274619  0.27281 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.00367e-07 ( -2.52376e-08  2.20777e-08 ) ergs/cm2

    Time-resolved spectra




    Distribution

    T90 vs. Hardness ratio plot 

    T90                                   = 0.436 sec.
Hardness ratio (energy fluence ratio) = 1.50065241463

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

    S(15-50 keV)  = 3.270387e-08
S(50-150 keV) = 5.835877e-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 = -1.011490977071833E+00, IMY = 3.854032440361417E-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:
-239.736000 -0.052000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 28.1340   3.2928    2.0  47.0   11.8   2.0538   5.6 ------	UNKNOWN

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

    Time interval of the image:
-0.052000 0.452000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 54.4277   7.6104    2.2  45.0   48.8   0.1575   5.2 ------	UNKNOWN                       
 79.4774 -10.6437    2.5  35.5   95.3   0.0793   4.6 ------	UNKNOWN                       
 19.3620   8.2995    2.4  55.8    5.3   0.1898   4.8 ------	UNKNOWN                       
136.0873 -51.1004    2.1  57.5  179.9   0.2425   5.6 ------	UNKNOWN                       
120.4831 -69.0160    1.1  47.3 -159.1   0.1621  10.4 ------	UNKNOWN                       
147.9854 -70.2264    2.2  56.6 -156.3   0.1851   5.2 ------	UNKNOWN

    Post-slew image of 15-350 keV band 

    Time interval of the image:
78.564620 962.431200
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.5506 -40.5616    1.4  29.6  137.1   5.2786   8.5    1.1	Vela X-1                      
170.2718 -60.6197    1.4  22.0 -154.0   3.6421   8.3    1.3	Cen X-3                       
186.6506 -62.8194    2.1  26.3 -137.2   2.6621   5.5    3.0	GX 301-2                      
184.6763 -66.6179    3.3  23.2 -131.4   1.4652   3.6 ------	UNKNOWN                       
223.6233 -70.6724    2.8  31.3 -104.8   2.5338   4.2 ------	UNKNOWN                       
228.7143 -57.4100    2.7  43.4 -114.6   8.9487   4.2 ------	UNKNOWN