Analysis Summary

Notes:

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.46
    Process Start Time: Mon Jan 20 04:15:28 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger303631
======================================================================

  Trigger: 00303631      Segment: 000

  BAT Trigger Time: 225071869.76   [s; MET]
      Trigger Stop: 225071873.856   [s; MET]
               UTC: 2008-02-18T23:57:47.175420    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 177.951347600546   Dec: -53.1004105987458  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.25
     Image Trigger?:     NO
     Rate S/N Ratio:     11.7898261225516  [ if not an image trigger ]
     Image S/N Ratio:    7.25

  Analysis Position:   [ source = BAT ]
    RA: 177.951347600546   Dec: -53.1004105987458  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 177.927442200414   Dec: -53.0870378471626  [deg; J2000]  
        { 11h 51m 42.6s , -53d 05' 13.3" }
         +/- 2.01258624932174 [arcmin] (estimated 90% radius based on SNR)
         +/- 1.39361482228635 [arcmin] (formal 1-sigma fit error)
    SNR: 11.1991065960042
 
  Angular difference between the analysis and refined position is 1.177143 arcmin
 
  Partial Coding Fraction: 0.1015625    [ including projection effects ]

  Duration
     T90: 6.5280000269413 +/- 1.42857693147711
        Measured from: -0.527999997138977
                   to: 6.00000002980232     [s; relative to TRIGTIME]
     T50: 2.94400000572205 +/- 1.20245082782922
        Measured from: 0.432000011205673
                   to: 3.37600001692772     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 0.412000000476837     
                   to: 1.41200000047684     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.84799998998642     
                   to: 6.57600000500679     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.482757   0.531959   0.097956   0.055327
           0.055665   0.059159   0.048200   0.041815 [error]
 Peak      0.123463   0.108841   0.054071   0.011913
           0.021487   0.023340   0.019477   0.015681 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100    7.424   -0.848    6.576
T90     6.528   -0.528    6.000
T50     2.944    0.432    3.376
Peak    1.000    0.412    1.412
 
 
====== 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      -2.531    -0.285      0.256       -           -               -         8.24e-03     -1.77e-03          1.77e-03      61.840   57
CPL      1.298    -2.146      4.860       27.026      -5.417         3.695      3.17e+00     -3.17e+00          6.77e+03      51.040   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      -3.264     -0.413     0.313       -           -               -         7.42e-03     -2.54e-03          2.40e-03      54.630   57
CPL     -1.000      N/A       N/A          80.000      N/A           N/A         7.15e-03        N/A               N/A         95.680   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   2.08e-07  2.05e-07  1.42e-07  1.55e-07  6.17e-07  7.10e-07   erg/cm2
      90%_error_low -3.34e-08 -3.15e-08 -3.92e-08 -6.75e-08 -9.93e-08 -1.37e-07   erg/cm2
      90%_error_hi   3.38e-08  3.09e-08  4.24e-08  9.58e-08  1.02e-07  1.56e-07   erg/cm2
Peak flux       PL   1.71e+00  6.23e-01  1.30e-01  3.21e-02  2.49e+00  2.50e+00   ph/cm2/s
      90%_error_low -4.25e-01 -1.55e-01 -5.18e-02 -1.79e-02 -5.68e-01 -5.69e-01   ph/cm2/s
      90%_error_hi   4.29e-01  1.51e-01  5.19e-02  2.33e-02  5.68e-01  5.70e-01   ph/cm2/s
 
Fluence        CPL    N/A      N/A      N/A      N/A      N/A      N/A      erg/cm2
      90%_error_low -3.34e-08 -3.15e-08 -3.92e-08 -6.75e-08 -9.93e-08 -1.37e-07   erg/cm2
      90%_error_hi   3.38e-08  3.09e-08  4.24e-08  9.58e-08  1.02e-07  1.56e-07   erg/cm2
Peak flux      CPL   1.52e+00  1.06e+00  1.94e-01  6.06e-03  2.79e+00  2.79e+00   ph/cm2/s
      90%_error_low -4.75e-01 -3.09e-01 -1.94e-01 -6.06e-03 -5.96e-01 -5.96e-01   ph/cm2/s
      90%_error_hi   4.73e-01  3.15e-01  1.01e-01  1.33e-02  5.96e-01  5.96e-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
  177.9274   -53.0870   0.0172    45.6740   140.4691         1.1752033     11.199 TRIG_00303631                 
 
Foreground time interval of the image:
 -0.848   6.576 (delta_t =   7.424 [sec])
Background time interval of the image:
-239.760  -0.848 (delta_t = 238.912 [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   -0.848 sec. to    6.576 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.53099     ( -0.285377   0.256229 )
Norm@50keV  : 8.23885E-03    ( -0.0017745   0.00176813 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          61.84 using 59 PHA bins.
# Reduced chi-squared =          1.085 for     57 degrees of freedom 
# Null hypothesis probability =   3.074100e-01
 
Photon flux (15-150 keV)    in 7.424 sec: 1.64994 ( -0.22281  0.22282 ) ph/cm2/s
Energy fluence (15-150 keV)             : 6.17004e-07 ( -9.92804e-08  1.02474e-07 ) ergs/cm2
    Cutoff power-law model
    Time interval is from   -0.848 sec. to    6.576 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 2.23391     ( -2.16884   4.83757 )
Epeak [keV] : 27.3685      ( -5.44053 3.67122 )
Norm@50keV  : 14.2225    ( -13.5206   6763.34 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          50.89 using 59 PHA bins.
# Reduced chi-squared =         0.9088 for     56 degrees of freedom 
# Null hypothesis probability =   6.680832e-01
 
Photon flux (15-150 keV)    in 7.424 sec: 1.55022 ( -0.222  0.2238 ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2

    1-s peak spectrum fit

    Power-law model
    Time interval is from    0.412 sec. to    1.412 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -3.264     ( -0.413049   0.313263 )
Norm@50keV  : 7.41514E-03    ( -0.00253738   0.00240295 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          54.63 using 59 PHA bins.
# Reduced chi-squared =         0.9584 for     57 degrees of freedom 
# Null hypothesis probability =   5.646130e-01
 
Photon flux (15-150 keV)    in 1 sec: 2.48755 ( -0.56774  0.56774 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.01793e-07 ( -2.37148e-08  2.36655e-08 ) ergs/cm2
    Cutoff power-law model
    Time interval is from    0.412 sec. to    1.412 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1     (       )
Epeak [keV] : 80.0000      (   )
Norm@50keV  : 7.15072E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          95.68 using 59 PHA bins.
# Reduced chi-squared =          1.709 for     56 degrees of freedom 
# Null hypothesis probability =   7.570057e-04
 
Photon flux (15-150 keV)    in 1 sec: 2.78884 ( -0.59566  0.59598 ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2

    Time-resolved spectra




    Distribution

    T90 vs. Hardness ratio plot 

    T90                                   = 6.528 sec.
Hardness ratio (energy fluence ratio) = 0.692117871471

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

    S(15-50 keV)  = 4.130721e-07
S(50-150 keV) = 2.0394792e-07

    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 = -7.896449343651111E-01, IMY = -6.516477441098890E-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:
-239.760000 -0.848000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
170.0455 -60.6471    5.8  37.0  140.8   1.1276   2.0    8.1	Cen X-3                       
186.1975 -62.7389    0.0  39.3  153.0  -0.9960  -1.9   12.8	GX 301-2                      
109.6942 -36.0917    4.0  39.1   64.4   2.7340   2.9 ------	UNKNOWN                       
184.7981 -50.2344    2.7  50.1  143.9   6.0223   4.3 ------	UNKNOWN                       
 73.3186 -21.1485    2.8  48.8   15.0   2.9833   4.1 ------	UNKNOWN                       
206.3529 -63.4004    2.4  42.7  166.0   2.5363   4.8 ------	UNKNOWN                       
 58.9000 -23.9173    2.6  46.8   -3.2   2.5423   4.5 ------	UNKNOWN                       
245.9646 -53.6892    2.7  56.2 -170.4   4.6671   4.3 ------	UNKNOWN                       
280.9373 -53.1322    3.0  55.2 -145.3   6.4991   3.8 ------	UNKNOWN                       
 21.2231 -30.9782    4.0  48.3  -49.8   3.8985   2.9 ------	UNKNOWN

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

    Time interval of the image:
-0.848000 6.576000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
170.1368 -60.7734    0.0  36.9  140.9   0.1052   1.8   10.4	Cen X-3                       
186.6124 -62.6592    4.4  39.5  153.2  -0.1351  -2.6    6.8	GX 301-2                      
177.9275 -53.0871    1.0  45.7  140.5   1.1741  11.2 ------	UNKNOWN                       
 65.4434 -15.5860    2.3  54.6    5.6   0.6821   5.1 ------	UNKNOWN                       
280.0246 -53.0497    2.5  55.4 -146.0   0.6800   4.6 ------	UNKNOWN                       
 31.3597 -20.5842    2.1  55.3  -34.6   0.8333   5.4 ------	UNKNOWN                       
  0.0620 -46.8166    2.5  41.1  -80.7   0.4832   4.6 ------	UNKNOWN

    Post-slew image of 15-350 keV band 

    Time interval of the image:
98.940600 962.340000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.5099 -40.5754    0.8  31.0   34.3   8.9700  13.7    1.5	Vela X-1                      
170.5279 -60.6649    2.6   8.6  -37.0   2.5080   4.5    6.7	Cen X-3                       
186.8501 -62.6407   16.8  10.6  -84.9   0.3516   0.7    9.4	GX 301-2                      
100.0829 -41.3354    3.2  51.5    7.6   5.7162   3.6 ------	UNKNOWN                       
226.4943 -11.2543    4.7  56.9  179.2   8.9368   2.5 ------	UNKNOWN                       
236.8705 -65.6079    3.3  31.1 -105.4   3.0644   3.6 ------	UNKNOWN