Analysis Summary

Notes:

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.46
    Process Start Time: Sun Jan 12 05:10:55 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger550457
======================================================================

  Trigger: 00550457      Segment: 000

  BAT Trigger Time: 384306672   [s; MET]
      Trigger Stop: 384306736   [s; MET]
               UTC: 2013-03-06T23:51:01.706560    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 279.477639697716   Dec: -11.6917684859571  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    9.36
     Image Trigger?:     YES
     Rate S/N Ratio:     0  [ if not an image trigger ]
     Image S/N Ratio:    9.36

  Analysis Position:   [ source = BAT ]
    RA: 279.477639697716   Dec: -11.6917684859571  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 279.475149639958   Dec: -11.6816241692119  [deg; J2000]  
        { 18h 37m 54.0s , -11d 40' 53.8" }
         +/- 1.62865950573679 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.684056681955427 [arcmin] (formal 1-sigma fit error)
    SNR: 15.1531760176516
 
  Angular difference between the analysis and refined position is 0.625996 arcmin
 
  Partial Coding Fraction: 0.1162109    [ including projection effects ]

  Duration
     T90: 272.379999935627 +/- 9.34031540434395
        Measured from: -154.708000004292
                   to: 117.671999931335     [s; relative to TRIGTIME]
     T50: 70.2719998955727 +/- 7.79203411923586
        Measured from: -141.191999971867
                   to: -70.9200000762939     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -138.276000022888     
                   to: -137.276000022888     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -159.472000002861     
                   to: 154.175999999046     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total    14.266416  17.432144  12.547985   2.448649
           0.309672   0.314097   0.285550   0.281103 [error]
 Peak      0.213427   0.266785   0.214018   0.069527
           0.013930   0.014435   0.013186   0.010803 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  313.648 -159.472  154.176
T90   272.380 -154.708  117.672
T50    70.272 -141.192  -70.920
Peak    1.000 -138.276 -137.276
 
 
====== 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      -1.749    -0.049      0.049       -           -               -         1.03e-02     -2.53e-04          2.53e-04      43.030   57
CPL     -1.558    -0.192      0.202      124.379     -37.967      3900.621      1.26e-02     -2.13e-03          2.95e-03      40.220   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      -1.573     -0.108     0.107       -           -               -         5.22e-02     -3.12e-03          3.11e-03      53.990   57
CPL     -1.547     -0.134     0.309      893.635    -893.635      -893.635      5.38e-02        N/A               N/A         54.090   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   5.20e-06  8.21e-06  9.77e-06  2.26e-05  2.97e-05  4.58e-05   erg/cm2
      90%_error_low -2.53e-07 -2.27e-07 -3.15e-07 -1.63e-06 -7.49e-07 -1.80e-06   erg/cm2
      90%_error_hi   2.59e-07  2.27e-07  3.14e-07  1.71e-06  7.50e-07  1.86e-06   erg/cm2
Peak flux       PL   2.31e+00  2.22e+00  1.49e+00  1.57e+00  6.66e+00  7.59e+00   ph/cm2/s
      90%_error_low -2.44e-01 -1.44e-01 -1.13e-01 -2.35e-01 -4.10e-01 -4.44e-01   ph/cm2/s
      90%_error_hi   2.53e-01  1.43e-01  1.12e-01  2.59e-01  4.11e-01  4.44e-01   ph/cm2/s
 
Fluence        CPL   4.96e-06  8.29e-06  9.89e-06  1.75e-05  2.93e-05  4.07e-05   erg/cm2
      90%_error_low -3.38e-07 -2.42e-07 -3.40e-07 -3.85e-06 -8.73e-07 -3.99e-06   erg/cm2
      90%_error_hi   3.46e-07  2.44e-07  3.43e-07  5.15e-06  8.69e-07  5.25e-06   erg/cm2
Peak flux      CPL   2.33e+00  2.21e+00  1.48e+00  1.56e+00  6.68e+00  7.73e+00   ph/cm2/s
      90%_error_low     N/A   -1.11e-01 -1.46e-01     N/A   -5.55e-01 -1.02e+00   ph/cm2/s
      90%_error_hi      N/A    1.02e-01  1.74e-01     N/A    4.96e-01  4.88e-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
  279.4751   -11.6816   0.0127    55.8867    -8.8617         9.9180040     15.153 TRIG_00550457                 
 
Foreground time interval of the image:
-11.299 154.176 (delta_t = 165.475 [sec])
Background time interval of the image:




    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 -159.472 sec. to  154.176 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.74896     ( -0.0491411   0.0489459 )
Norm@50keV  : 1.02716E-02    ( -0.000253383   0.000253176 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          43.03 using 59 PHA bins.
# Reduced chi-squared =         0.7548 for     57 degrees of freedom 
# Null hypothesis probability =   9.147120e-01
 
Photon flux (15-150 keV)    in 313.6 sec: 1.38843 ( -0.03937  0.03958 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.97294e-05 ( -7.48892e-07  7.49968e-07 ) ergs/cm2
    Cutoff power-law model
    Time interval is from -159.472 sec. to  154.176 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.55839     ( -0.192362   0.202415 )
Epeak [keV] : 124.379      ( -37.9665 3900.63 )
Norm@50keV  : 1.25852E-02    ( -0.00212818   0.0029483 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          40.22 using 59 PHA bins.
# Reduced chi-squared =         0.7182 for     56 degrees of freedom 
# Null hypothesis probability =   9.447139e-01
 
Photon flux (15-150 keV)    in 313.6 sec: 1.36390 ( -0.04591  0.04631 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.92864e-05 ( -8.72827e-07  8.69051e-07 ) ergs/cm2

    1-s peak spectrum fit

    Power-law model
    Time interval is from -138.276 sec. to -137.276 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.57337     ( -0.107971   0.107283 )
Norm@50keV  : 5.22230E-02    ( -0.0031216   0.00311284 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          53.99 using 59 PHA bins.
# Reduced chi-squared =         0.9472 for     57 degrees of freedom 
# Null hypothesis probability =   5.887150e-01
 
Photon flux (15-150 keV)    in 1 sec: 6.65692 ( -0.40951  0.41084 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.90117e-07 ( -3.13629e-08  3.15219e-08 ) ergs/cm2
    Cutoff power-law model
    Time interval is from -138.276 sec. to -137.276 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.57119     ( -0.133322   0.31009 )
Epeak [keV] : 1.00000E+04      ( -10000 -10000 )
Norm@50keV  : 5.23568E-02    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          54.00 using 59 PHA bins.
# Reduced chi-squared =         0.9642 for     56 degrees of freedom 
# Null hypothesis probability =   5.510336e-01
 
Photon flux (15-150 keV)    in 1 sec: 6.68408 ( -0.55532  0.49632 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.92516e-07 ( -4.59969e-08  4.01562e-08 ) ergs/cm2

    Time-resolved spectra




    Distribution

    T90 vs. Hardness ratio plot 

    T90                                   = N/A sec.
Hardness ratio (energy fluence ratio) = N/A

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

    S(15-50 keV)  = N/A
S(50-150 keV) = N/A

    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 = 1.458634699968526E+00, IMY = 2.274181447674928E-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:

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

    Time interval of the image:
-11.299400 154.176000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.6371  35.2990   34.0  33.5   63.2  -0.1249  -0.3    9.2	Her X-1                       
268.4636  -1.4705    8.4  50.4    8.6  -0.6543  -1.4    5.8	SW J1753.5-0127               
288.7944  10.9534    0.7  31.7  -14.2   3.3183  16.7    0.5	GRS 1915+105                  
299.5637  35.2188    1.9   6.9  -46.9   0.9722   6.0    1.7	Cyg X-1                       
308.1115  40.9375    2.3   8.3 -117.6   0.7883   5.0    0.9	Cyg X-3                       
326.2472  38.3457    6.4  22.5 -120.8   0.3516   1.8    3.8	Cyg X-2                       
257.4515   1.7242    2.8  53.6   22.6   4.1932   4.2 ------	UNKNOWN                       
279.4752 -11.6816    0.8  55.9   -8.9   9.9167  15.2 ------	UNKNOWN                       
  4.3087  52.5882    2.8  45.2 -157.7   1.3664   4.2 ------	UNKNOWN                       
337.3603  18.6945    6.1  41.2  -98.2   1.6634   1.9 ------	UNKNOWN

    Post-slew image of 15-350 keV band 

    Time interval of the image:
546.400600 963.041900
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.6081  35.4232   10.0  34.1   69.2   0.7558   1.2    8.8	Her X-1                       
268.2804  -1.3197    7.7  50.9   15.2   1.7894   1.5    9.6	SW J1753.5-0127               
288.7895  10.9529    0.7  32.0   -7.3   6.3593  16.7    0.7	GRS 1915+105                  
299.5565  35.2688    1.6   6.7  -35.6   2.1875   7.2    4.4	Cyg X-1                       
308.1564  40.9611    1.3   7.7 -110.9   2.5354   8.6    2.2	Cyg X-3                       
326.1621  38.1725    6.7  21.8 -114.1   0.6356   1.7    9.0	Cyg X-2                       
283.7127  22.4600    3.5  22.8   11.5   0.9893   3.3 ------	UNKNOWN