Analysis Summary

Notes:

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.46
    Process Start Time: Sun Jan 19 23:51:46 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger318094
======================================================================

  Trigger: 00318094      Segment: 000

  BAT Trigger Time: 238831062.336   [s; MET]
      Trigger Stop: 238831067.84   [s; MET]
               UTC: 2008-07-27T05:57:39.363900    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 208.388757842545   Dec: -18.5488483391044  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.3
     Image Trigger?:     NO
     Rate S/N Ratio:     14.422205101856  [ if not an image trigger ]
     Image S/N Ratio:    7.3

  Analysis Position:   [ source = BAT ]
    RA: 208.388757842545   Dec: -18.5488483391044  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 208.42327439217   Dec: -18.5770668090244  [deg; J2000]  
        { 13h 53m 41.6s , -18d 34' 37.4" }
         +/- 2.43684074756541 [arcmin] (estimated 90% radius based on SNR)
         +/- 1.23948242939938 [arcmin] (formal 1-sigma fit error)
    SNR: 8.52134538587885
 
  Angular difference between the analysis and refined position is 2.592481 arcmin
 
  Partial Coding Fraction: 0.9765625    [ including projection effects ]

  Duration
     T90: 4.91200000047684 +/- 0.915860247912174
        Measured from: 0.0600000023841858
                   to: 4.97200000286102     [s; relative to TRIGTIME]
     T50: 2.72400000691414 +/- 1.24247012366982
        Measured from: 1.02000001072884
                   to: 3.74400001764297     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 1.2039999961853     
                   to: 2.2039999961853     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.139999985694885     
                   to: 5.1879999935627     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.047941   0.069122   0.066854   0.025742
           0.013936   0.012573   0.011424   0.010243 [error]
 Peak      0.013045   0.012105   0.015474   0.015841
           0.005996   0.005458   0.004962   0.004534 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100    5.328   -0.140    5.188
T90     4.912    0.060    4.972
T50     2.724    1.020    3.744
Peak    1.000    1.204    2.204
 
 
====== 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      -1.223    -0.340      0.345       -           -               -         2.49e-03     -4.57e-04          4.57e-04      40.980   57
CPL     -0.757    -1.800      1.623      147.650    -147.650      -147.650      4.06e-03        N/A               N/A         40.580   56
 
 
=== 1-s peak spectral analysis ===
(Best model with acceptable fit: N/A)
 
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      -0.207      1.919     0.207       -           -               -         2.44e-03     -2.44e-03          -1.97e-03      48.010   57
CPL     -0.320     -0.839     0.320     9999.360    -9999.360      -9999.360      2.58e-03     -2.58e-03          -2.58e-03      48.080   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   1.31e-08  2.85e-08  4.88e-08  1.93e-07  1.34e-07  2.84e-07   erg/cm2
      90%_error_low -4.41e-09 -6.09e-09 -1.10e-08 -8.28e-08 -2.73e-08 -9.16e-08   erg/cm2
      90%_error_hi   5.00e-09  5.93e-09  1.09e-08  1.20e-07  2.78e-08  1.24e-07   erg/cm2
Peak flux       PL   2.93e-02  6.46e-02  1.12e-01  4.56e-01  3.08e-01  6.61e-01   ph/cm2/s
      90%_error_low -2.93e-02 -6.46e-02 -1.12e-01 -1.01e-01 -3.08e-01 -2.84e-01   ph/cm2/s
      90%_error_hi   6.58e-02  6.10e-02  -7.01e-02  1.40e+00  9.00e-02  1.41e+00   ph/cm2/s
 
Fluence        CPL   1.17e-08  2.93e-08  5.08e-08  1.06e-07  1.30e-07  1.97e-07   erg/cm2
      90%_error_low -5.62e-09 -6.54e-09 -1.21e-08 -8.01e-08 -2.97e-08 -8.69e-08   erg/cm2
      90%_error_hi   5.97e-09  6.77e-09  1.28e-08  1.15e-07  2.98e-08  1.22e-07   erg/cm2
Peak flux      CPL     N/A      N/A      N/A      N/A      N/A      N/A     ph/cm2/s
      90%_error_low -2.93e-02 -6.46e-02 -1.12e-01 -1.01e-01 -3.08e-01 -2.84e-01   ph/cm2/s
      90%_error_hi   6.58e-02  6.10e-02  -7.01e-02  1.40e+00  9.00e-02  1.41e+00   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
  208.4233   -18.5771   0.0225    16.9168  -141.6893         0.2136885      8.521 TRIG_00318094                 
 
Foreground time interval of the image:
 -0.140   5.188 (delta_t =   5.328 [sec])
Background time interval of the image:
-239.336  -0.140 (delta_t = 239.196 [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   -0.140 sec. to    5.188 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.223     ( -0.339654   0.345114 )
Norm@50keV  : 2.49201E-03    ( -0.000456656   0.00045662 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          40.98 using 59 PHA bins.
# Reduced chi-squared =         0.7189 for     57 degrees of freedom 
# Null hypothesis probability =   9.458259e-01
 
Photon flux (15-150 keV)    in 5.328 sec: 0.293495 ( -0.055428  0.055755 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.33861e-07 ( -2.73061e-08  2.78329e-08 ) ergs/cm2
    Cutoff power-law model
    Time interval is from   -0.140 sec. to    5.188 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.756822     ( -1.80055   1.62195 )
Epeak [keV] : 147.650      ( -147.513 -147.513 )
Norm@50keV  : 4.06128E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          40.58 using 59 PHA bins.
# Reduced chi-squared =         0.7246 for     56 degrees of freedom 
# Null hypothesis probability =   9.398132e-01
 
Photon flux (15-150 keV)    in 5.328 sec: 0.285374 ( -0.059638  0.059501 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.29689e-07 ( -2.9716e-08  2.98413e-08 ) ergs/cm2

    1-s peak spectrum fit

    Power-law model
    Time interval is from    1.204 sec. to    2.204 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 2.20325     ( -0.467057   -2.17879 )
Norm@50keV  : 1.33153E-04    ( -0.000132892   0.000329942 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          46.64 using 59 PHA bins.
# Reduced chi-squared =         0.8183 for     57 degrees of freedom 
# Null hypothesis probability =   8.345875e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.307594 7.47573E-02 7.12668E-02 (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.84238e-08 ( -1.30807e-08  1.29628e-08 ) ergs/cm2
    Cutoff power-law model
    Time interval is from    1.204 sec. to    2.204 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.216074     ( -0.844491   0.314515 )
Epeak [keV] : 1.00000E+04      ( -10000 -10000 )
Norm@50keV  : 2.48657E-03    ( -0.00248535   -0.00248535 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          48.04 using 59 PHA bins.
# Reduced chi-squared =         0.8578 for     56 degrees of freedom 
# Null hypothesis probability =   7.665048e-01
 
Photon flux (15-150 keV)    in 1 sec:  (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.83319e-08 ( -1.30249e-08  1.305e-08 ) ergs/cm2

    Time-resolved spectra




    Distribution

    T90 vs. Hardness ratio plot 

    T90                                   = 4.912 sec.
Hardness ratio (energy fluence ratio) = 1.71360185082

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

    S(15-50 keV)  = 4.158815e-08
S(50-150 keV) = 9.22734e-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 = -2.386495244269264E-01, IMY = 1.885466209781005E-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:
-239.336000 -0.140000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
244.9833 -15.6420    0.2  20.3   77.8  23.7871  66.8    0.2	Sco X-1                       
254.3380  35.3462   23.1  54.9    4.0  -0.6104  -0.5    5.9	Her X-1                       
255.9437 -37.8726    2.0  38.4  112.7   5.0676   5.6    2.7	4U 1700-377                   
256.5756 -36.5607    0.0  38.1  110.4   1.2752   1.4   10.7	GX 349+2                      
263.1323 -24.6520   20.5  38.8   89.2   0.7017   0.6    8.8	GX 1+4                        
267.2581   1.8295    2.3  44.6   49.4   6.1946   5.1 ------	UNKNOWN                       
166.5453 -42.9194    3.6  58.7 -159.2   7.5156   3.2 ------	UNKNOWN                       
206.5114  36.1345    3.5  50.7  -44.5   5.8295   3.3 ------	UNKNOWN

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

    Time interval of the image:
-0.140000 5.188000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
245.0488 -15.8183    6.7  20.4   78.2  -0.0516  -1.7   11.4	Sco X-1                       
254.5331  35.3191    3.2  55.0    4.2   0.4097   3.6    4.0	Her X-1                       
255.8189 -37.7784    9.7  38.3  112.6  -0.0937  -1.2    8.9	4U 1700-377                   
256.6187 -36.3430    4.8  38.0  110.1   0.1950   2.4   10.1	GX 349+2                      
263.0660 -24.8774  101.5  38.8   89.6   0.0116   0.1    8.5	GX 1+4                        
255.6234  27.9158    2.9  49.8   11.0   0.2709   4.0 ------	UNKNOWN                       
208.4233 -18.5771    1.3  16.9 -141.7   0.2136   8.5 ------	UNKNOWN

    Post-slew image of 15-350 keV band 

    Time interval of the image:
92.764600 962.725600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
170.1405 -60.5719    6.4  50.0 -177.2   3.0650   1.8    6.0	Cen X-3                       
186.6427 -62.8099    3.5  46.8  172.8   4.8836   3.3    2.4	GX 301-2                      
244.9752 -15.6364    0.3  35.0   70.4  65.1401  39.4    0.3	Sco X-1                       
201.3085 -43.0448    1.8  25.2  171.6   4.0928   6.5 ------	UNKNOWN                       
205.2890  32.6290    3.4  51.3  -24.0   4.4295   3.4 ------	UNKNOWN                       
187.5782  28.0079    4.2  50.7  -44.5  10.4676   2.8 ------	UNKNOWN                       
167.8930  -6.6301    4.6  41.2  -99.2  10.4106   2.5 ------	UNKNOWN