Analysis Summary

Notes:

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.46
    Process Start Time: Mon Jan 13 21:23:47 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger458918
======================================================================

  Trigger: 00458918      Segment: 000

  BAT Trigger Time: 334477141.44   [s; MET]
      Trigger Stop: 334477149.632   [s; MET]
               UTC: 2011-08-08T06:18:54.201560    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 57.2642206519533   Dec: -44.1786208592457  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.19
     Image Trigger?:     NO
     Rate S/N Ratio:     10  [ if not an image trigger ]
     Image S/N Ratio:    7.19

  Analysis Position:   [ source = BAT ]
    RA: 57.2642206519533   Dec: -44.1786208592457  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 57.3161099519403   Dec: -44.1874910933551  [deg; J2000]  
        { 03h 49m 15.9s , -44d 11' 15.0" }
         +/- 2.29524687581232 [arcmin] (estimated 90% radius based on SNR)
         +/- 1.38573959706836 [arcmin] (formal 1-sigma fit error)
    SNR: 9.28213331131464
 
  Angular difference between the analysis and refined position is 2.295199 arcmin
 
  Partial Coding Fraction: 0.765625    [ including projection effects ]

  Duration
     T90: 40.7040000557899 +/- 9.02859461372617
        Measured from: 0.639999985694885
                   to: 41.3440000414848     [s; relative to TRIGTIME]
     T50: 21.2000000476837 +/- 13.3713508979011
        Measured from: 3.02399998903275
                   to: 24.2240000367165     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 1.18800002336502     
                   to: 2.18800002336502     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.272000014781952     
                   to: 44.7680000066757     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.271722   0.324640   0.115559   0.021219
           0.046201   0.047217   0.041435   0.037888 [error]
 Peak      0.015582   0.037514   0.012492   0.007124
           0.007334   0.007409   0.006394   0.005691 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   45.040   -0.272   44.768
T90    40.704    0.640   41.344
T50    21.200    3.024   24.224
Peak    1.000    1.188    2.188
 
 
====== 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      -2.105    -0.372      0.333       -           -               -         8.82e-04     -2.29e-04          2.23e-04      54.410   57
CPL     -1.346    -1.059      2.602       31.803      N/A           N/A         2.64e-03        N/A               N/A         53.530   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      -1.851     -0.521     0.461       -           -               -         4.15e-03     -1.48e-03          1.43e-03      59.150   57
CPL      0.498     -2.299    -0.498       43.217     -14.801        77.418      9.74e-02     -9.74e-02          -9.74e-02      56.070   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   8.98e-08  1.14e-07  1.06e-07  1.74e-07  3.69e-07  4.84e-07   erg/cm2
      90%_error_low -2.09e-08 -2.21e-08 -3.57e-08 -9.09e-08 -8.39e-08 -1.43e-07   erg/cm2
      90%_error_hi   2.13e-08  2.18e-08  3.83e-08  1.42e-07  8.82e-08  1.83e-07   erg/cm2
Peak flux       PL   2.39e-01  1.96e-01  1.08e-01  8.85e-02  5.83e-01  6.32e-01   ph/cm2/s
      90%_error_low -9.31e-02 -5.87e-02 -4.68e-02 -5.53e-02 -1.75e-01 -1.91e-01   ph/cm2/s
      90%_error_hi   1.00e-01  5.87e-02  4.89e-02  9.07e-02  1.75e-01  1.94e-01   ph/cm2/s
 
Fluence        CPL   8.76e-08  1.25e-07  9.52e-08  1.77e-07  3.36e-07  4.90e-07   erg/cm2
      90%_error_low -2.22e-08    N/A    -6.09e-08 -5.12e-08 -9.44e-08    N/A      erg/cm2
      90%_error_hi   2.22e-08    N/A     4.55e-08  1.10e-07  1.05e-07    N/A      erg/cm2
Peak flux      CPL   1.97e-01  2.57e-01  1.00e-01  7.43e-03  5.60e-01  5.61e-01   ph/cm2/s
      90%_error_low -1.17e-01 -8.54e-02 -1.00e-01 -7.43e-03 -1.97e-01 -1.98e-01   ph/cm2/s
      90%_error_hi   1.12e-01  1.22e-01  6.66e-02  7.97e-02  1.75e-01  1.77e-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
   57.3161   -44.1875   0.0205    29.2649   170.3273         0.8625464      9.282 TRIG_00458918                 
 
Foreground time interval of the image:
 -0.272  44.768 (delta_t =  45.040 [sec])
Background time interval of the image:
-239.440  -0.272 (delta_t = 239.168 [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   -0.272 sec. to   44.768 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.10532     ( -0.372195   0.333371 )
Norm@50keV  : 8.81694E-04    ( -0.000229301   0.000222713 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          54.41 using 59 PHA bins.
# Reduced chi-squared =         0.9546 for     57 degrees of freedom 
# Null hypothesis probability =   5.727564e-01
 
Photon flux (15-150 keV)    in 45.04 sec: 0.139091 ( -0.025362  0.025366 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.69223e-07 ( -8.39248e-08  8.81798e-08 ) ergs/cm2
    Cutoff power-law model
    Time interval is from   -0.272 sec. to   44.768 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.34588     ( -1.05893   2.60211 )
Epeak [keV] : 31.8031      (   )
Norm@50keV  : 2.64132E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          53.53 using 59 PHA bins.
# Reduced chi-squared =         0.9559 for     56 degrees of freedom 
# Null hypothesis probability =   5.688423e-01
 
Photon flux (15-150 keV)    in 45.04 sec: 0.136211 ( -0.025751  0.025841 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.3634e-07 ( -9.43993e-08  1.05077e-07 ) ergs/cm2

    1-s peak spectrum fit

    Power-law model
    Time interval is from    1.188 sec. to    2.188 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.85103     ( -0.520232   0.462355 )
Norm@50keV  : 4.14678E-03    ( -0.0014776   0.00143533 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          59.15 using 59 PHA bins.
# Reduced chi-squared =          1.038 for     57 degrees of freedom 
# Null hypothesis probability =   3.970989e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.583162 ( -0.174797  0.174844 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.81215e-08 ( -1.30841e-08  1.37681e-08 ) ergs/cm2
    Cutoff power-law model
    Time interval is from    1.188 sec. to    2.188 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 0.498315     ( -2.33867   -0.5378 )
Epeak [keV] : 43.2172      ( -14.5121 77.7067 )
Norm@50keV  : 9.73869E-02    ( -0.109098   -0.109098 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          56.07 using 59 PHA bins.
# Reduced chi-squared =          1.001 for     56 degrees of freedom 
# Null hypothesis probability =   4.723654e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.560450 ( -0.19723  0.174627 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.24586e-08 ( -1.44558e-08  1.44033e-08 ) ergs/cm2

    Time-resolved spectra




    Distribution

    T90 vs. Hardness ratio plot 

    T90                                   = 40.704 sec.
Hardness ratio (energy fluence ratio) = 0.92965076734

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

    S(15-50 keV)  = 2.0419502e-07
S(50-150 keV) = 1.6503284e-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 = -5.524030337878577E-01, IMY = -9.415320014049408E-02

    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:
-239.440000 -0.272000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.5544 -40.5644    5.6  38.3  -76.4   1.2660   2.1    1.3	Vela X-1                      
170.3122 -60.6224    3.2  33.4  -26.1   0.9439   3.6    0.1	Cen X-3                       
186.5858 -62.7815    2.0  36.4  -13.1   1.6251   5.9    2.1	GX 301-2                      
 19.8535 -46.2684    2.4  39.4  126.3   3.1395   4.8 ------	UNKNOWN                       
202.9077 -50.1117    2.6  51.8  -10.8   2.2886   4.4 ------	UNKNOWN                       
195.5555 -40.5647    2.8  58.5  -21.2   5.5161   4.1 ------	UNKNOWN                       
 80.9631 -12.2460    2.6  57.3 -150.3   5.5922   4.4 ------	UNKNOWN                       
 85.4122 -14.1152    4.3  55.3 -145.2   3.7080   2.7 ------	UNKNOWN                       
168.7052 -39.6442    3.6  50.6  -44.4   3.2720   3.2 ------	UNKNOWN

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

    Time interval of the image:
-0.272000 44.768000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.3500 -40.6553    6.1  38.2  -76.5  -0.3841  -1.9   10.1	Vela X-1                      
170.3605 -60.5887   79.4  33.5  -26.1  -0.0141  -0.1    2.4	Cen X-3                       
186.4205 -62.8725    5.0  36.3  -13.1  -0.2364  -2.3    8.9	GX 301-2                      
 57.3161 -44.1876    1.2  29.3  170.3   0.8629   9.3 ------	UNKNOWN                       
 58.2977 -17.0908    2.3  55.2 -177.3   1.5943   5.1 ------	UNKNOWN

    Post-slew image of 15-350 keV band 

    Time interval of the image:
100.060590 721.760610
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 18.2436  -9.3403    3.0  48.5  142.3   7.9219   3.9 ------	UNKNOWN                       
 70.9789   9.6778    4.3  55.3 -145.2   8.4001   2.7 ------	UNKNOWN                       
 89.1662 -11.0581    3.3  43.0 -112.2   7.8931   3.5 ------	UNKNOWN