Analysis Summary

Notes:

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.46
    Process Start Time: Mon Jan 20 09:43:54 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger279592
======================================================================

  Trigger: 00279592      Segment: 000

  BAT Trigger Time: 201191183.168   [s; MET]
      Trigger Stop: 201191184.192   [s; MET]
               UTC: 2007-05-18T14:26:21.204860    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 254.223225939659   Dec: 55.2965244404127  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.22
     Image Trigger?:     NO
     Rate S/N Ratio:     12.2065556157337  [ if not an image trigger ]
     Image S/N Ratio:    7.22

  Analysis Position:   [ source = BAT ]
    RA: 254.223225939659   Dec: 55.2965244404127  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 254.218370508371   Dec: 55.294209765254  [deg; J2000]  
        { 16h 56m 52.4s , +55d 17' 39.2" }
         +/- 1.75862184717613 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.871825407022529 [arcmin] (formal 1-sigma fit error)
    SNR: 13.5791317730875
 
  Angular difference between the analysis and refined position is 0.216331 arcmin
 
  Partial Coding Fraction: 0.84375    [ including projection effects ]

  Duration
     T90: 5.50400000810623 +/- 0.804114425456228
        Measured from: -1.32800000905991
                   to: 4.17599999904633     [s; relative to TRIGTIME]
     T50: 2.73600000143051 +/- 0.82873400061398
        Measured from: -0.316000014543533
                   to: 2.41999998688698     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 0.123999983072281     
                   to: 1.12399998307228     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -1.78400000929832     
                   to: 4.50399997830391     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.131626   0.137813   0.050070  -0.000988
           0.012785   0.013165   0.011227   0.009371 [error]
 Peak      0.034282   0.035470   0.011886   0.001676
           0.005304   0.005430   0.004669   0.003759 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100    6.288   -1.784    4.504
T90     5.504   -1.328    4.176
T50     2.736   -0.316    2.420
Peak    1.000    0.124    1.124
 
 
====== 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      -2.011    -0.234      0.220       -           -               -         2.89e-03     -4.49e-04          4.37e-04      66.440   57
CPL     -1.838    -0.554      1.085       37.467      N/A           N/A         3.66e-03        N/A               N/A         66.320   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      -2.011     -0.383     0.345       -           -               -         4.42e-03     -1.15e-03          1.11e-03      59.730   57
CPL     -1.809     -0.320     2.448       36.370      N/A           N/A         5.89e-03        N/A               N/A         59.660   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   3.75e-08  5.06e-08  5.02e-08  8.98e-08  1.67e-07  2.28e-07   erg/cm2
      90%_error_low -5.96e-09 -5.94e-09 -1.05e-08 -3.23e-08 -2.39e-08 -4.54e-08   erg/cm2
      90%_error_hi   6.08e-09  5.91e-09  1.08e-08  4.29e-08  2.46e-08  5.38e-08   erg/cm2
Peak flux       PL   2.98e-01  2.22e-01  1.10e-01  7.79e-02  6.67e-01  7.08e-01   ph/cm2/s
      90%_error_low -7.43e-02 -4.23e-02 -3.63e-02 -3.97e-02 -1.24e-01 -1.36e-01   ph/cm2/s
      90%_error_hi   7.65e-02  4.20e-02  3.80e-02  5.96e-02  1.24e-01  1.37e-01   ph/cm2/s
 
Fluence        CPL   3.71e-08  5.17e-08  4.95e-08  6.22e-08  1.64e-07  2.00e-07   erg/cm2
      90%_error_low    N/A    -1.01e-08 -1.28e-08 -5.18e-08 -2.98e-08 -6.31e-08   erg/cm2
      90%_error_hi     N/A     8.47e-09  1.13e-08  6.44e-08  2.71e-08  7.82e-08   erg/cm2
Peak flux      CPL   2.95e-01  2.28e-01  1.09e-01  5.43e-02  6.62e-01  6.86e-01   ph/cm2/s
      90%_error_low     N/A       N/A   -2.90e-02 -5.43e-02 -1.28e-01 -1.48e-01   ph/cm2/s
      90%_error_hi      N/A       N/A    3.95e-02  5.76e-02  1.27e-01  1.63e-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
  254.2184    55.2942   0.0141    18.8324   -56.3924         0.3239575     13.579 TRIG_00279592                 
 
Foreground time interval of the image:
 -1.784   4.504 (delta_t =   6.288 [sec])
Background time interval of the image:
-239.168  -1.784 (delta_t = 237.384 [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   -1.784 sec. to    4.504 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.01088     ( -0.234422   0.220264 )
Norm@50keV  : 2.88590E-03    ( -0.000449007   0.000436878 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          66.44 using 59 PHA bins.
# Reduced chi-squared =          1.166 for     57 degrees of freedom 
# Null hypothesis probability =   1.838341e-01
 
Photon flux (15-150 keV)    in 6.288 sec: 0.435097 ( -0.049939  0.049941 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.67476e-07 ( -2.39327e-08  2.4622e-08 ) ergs/cm2
    Cutoff power-law model
    Time interval is from   -1.784 sec. to    4.504 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.83779     ( -0.554416   1.08512 )
Epeak [keV] : 37.4673      (   )
Norm@50keV  : 3.66214E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          66.32 using 59 PHA bins.
# Reduced chi-squared =          1.184 for     56 degrees of freedom 
# Null hypothesis probability =   1.626829e-01
 
Photon flux (15-150 keV)    in 6.288 sec: 0.432133 ( -0.052268  0.051735 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.63697e-07 ( -2.98276e-08  2.71132e-08 ) ergs/cm2

    1-s peak spectrum fit

    Power-law model
    Time interval is from    0.124 sec. to    1.124 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.01107     ( -0.383347   0.344691 )
Norm@50keV  : 4.42239E-03    ( -0.00115084   0.00110643 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          59.73 using 59 PHA bins.
# Reduced chi-squared =          1.048 for     57 degrees of freedom 
# Null hypothesis probability =   3.767720e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.666809 ( -0.124307  0.124319 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.0815e-08 ( -9.59018e-09  1.00653e-08 ) ergs/cm2
    Cutoff power-law model
    Time interval is from    0.124 sec. to    1.124 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.80886     ( -0.32042   2.44784 )
Epeak [keV] : 36.3701      (   )
Norm@50keV  : 5.89235E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          59.66 using 59 PHA bins.
# Reduced chi-squared =          1.065 for     56 degrees of freedom 
# Null hypothesis probability =   3.441603e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.662449 ( -0.127719  0.127093 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.96543e-08 ( -1.23375e-08  9.81776e-09 ) ergs/cm2

    Time-resolved spectra




    Distribution

    T90 vs. Hardness ratio plot 

    T90                                   = 5.504 sec.
Hardness ratio (energy fluence ratio) = 0.992521570112

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

    S(15-50 keV)  = 8.809256e-08
S(50-150 keV) = 7.938177e-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 = 1.887765493872842E-01, IMY = 2.840501912307377E-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:
-239.168000 -1.784000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.4538  35.3464    0.8  18.6    9.0   2.0904  14.9    0.3	Her X-1                       
299.5893  35.1892    1.0  51.4  -22.6   4.6493  12.0    0.7	Cyg X-1                       
308.2507  40.9528    4.2  54.5  -33.1   2.2215   2.8    6.4	Cyg X-3                       
256.2554   2.7666    2.8  45.3   48.2   2.5585   4.1 ------	UNKNOWN                       
171.2061  34.2756    2.5  47.6 -176.1   1.3349   4.6 ------	UNKNOWN                       
160.3497  28.9759    2.9  58.2 -175.5   3.7831   4.0 ------	UNKNOWN                       
195.0214  52.5157    2.3  26.7 -152.8   0.8067   5.1 ------	UNKNOWN                       
188.9274  55.4063    2.7  30.5 -147.6   0.7619   4.3 ------	UNKNOWN                       
305.4118  28.7584    2.1  59.0  -19.3   5.2727   5.5 ------	UNKNOWN

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

    Time interval of the image:
-1.784000 4.504000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.3138  35.4530    3.7  18.4    8.9   0.0661   3.1    9.7	Her X-1                       
299.4845  35.2180    6.3  51.3  -22.6  -0.1031  -1.8    5.3	Cyg X-1                       
308.1996  41.1535    8.4  54.3  -33.3  -0.1499  -1.4   12.7	Cyg X-3                       
254.2184  55.2942    0.8  18.8  -56.4   0.3240  13.6 ------	UNKNOWN                       
163.2712  39.1204    2.6  50.9 -166.4   0.2248   4.4 ------	UNKNOWN

    Post-slew image of 15-350 keV band 

    Time interval of the image:
59.532590 902.871500
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.4463  35.3370    0.7  19.9   70.9   7.3068  16.8    0.6	Her X-1                       
288.8049  10.9485    1.9  51.9   26.3  11.3884   6.1    0.4	GRS 1915+105                  
299.5662  35.1868    0.4  36.8   -4.7  14.9707  26.6    1.5	Cyg X-1                       
307.9815  40.8713   21.4  37.6  -19.1  -0.2727  -0.5    7.6	Cyg X-3                       
326.2169  38.3678    8.1  49.6  -30.3   1.2408   1.4    3.5	Cyg X-2                       
192.3642  30.7666    3.3  49.4  158.2   4.7117   3.5 ------	UNKNOWN                       
193.6580  40.5401    2.6  41.7  166.8   3.1219   4.5 ------	UNKNOWN                       
296.0356  29.7430    2.3  39.1    4.7   2.8137   5.1 ------	UNKNOWN                       
308.0455  37.6301    0.8  39.8  -15.3   8.3946  14.9 ------	UNKNOWN                       
160.4621  41.7713    4.2  58.7 -169.2   8.1747   2.8 ------	UNKNOWN