Analysis Summary

Notes:

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.46
    Process Start Time: Mon Jul 15 19:03:24 EDT 2019
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger903845
======================================================================

  Trigger: 00903845      Segment: 000

  BAT Trigger Time: 579629084.224   [s; MET]
      Trigger Stop: 579629086.272   [s; MET]
               UTC: 2019-05-15T16:04:21.314940    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 98.8398449449947   Dec: 52.2947102013463  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    9.98
     Image Trigger?:     NO
     Rate S/N Ratio:     7.41619848709566  [ if not an image trigger ]
     Image S/N Ratio:    9.98

  Analysis Position:   [ source = BAT ]
    RA: 98.8398449449947   Dec: 52.2947102013463  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 98.8333612658648   Dec: 52.3209179182834  [deg; J2000]  
        { 06h 35m 20.0s , +52d 19' 15.3" }
         +/- 1.42102456969087 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.634172757131786 [arcmin] (formal 1-sigma fit error)
    SNR: 18.4126421553458
 
  Angular difference between the analysis and refined position is 1.590351 arcmin
 
  Partial Coding Fraction: 0.6796875    [ including projection effects ]

  Duration
     T90: 46.5119999647141 +/- 9.64451343727788
        Measured from: -20.135999917984
                   to: 26.37600004673     [s; relative to TRIGTIME]
     T50: 14.3680000305176 +/- 2.80114262250384
        Measured from: -4.32799994945526
                   to: 10.0400000810623     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.388000011444092     
                   to: 0.611999988555908     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -25.5440000295639     
                   to: 31.8000000715256     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.940217   0.949570   0.643713   0.165924
           0.068458   0.070549   0.061163   0.051443 [error]
 Peak      0.035895   0.066082   0.030508   0.011655
           0.009578   0.010319   0.008893   0.007166 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   57.344  -25.544   31.800
T90    46.512  -20.136   26.376
T50    14.368   -4.328   10.040
Peak    1.000   -0.388    0.612
 
 
====== 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      -1.788    -0.155      0.151       -           -               -         2.79e-03     -2.58e-04          2.54e-04      52.770   57
CPL     -1.795    -0.149      0.350     9999.360    -9999.350      -9999.360      2.78e-03     -1.59e-03          1.43e-03      52.790   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      -1.604     -0.341     0.328       -           -               -         8.64e-03     -1.95e-03          1.92e-03      47.990   57
CPL     -0.149     -1.568     2.998       56.160     -15.995       -56.160      5.61e-02     -5.61e-02          3.03e+00      45.690   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   2.68e-07  4.14e-07  4.79e-07  1.07e-06  1.48e-06  2.23e-06   erg/cm2
      90%_error_low -3.38e-08 -3.32e-08 -6.08e-08 -2.56e-07 -1.39e-07 -3.17e-07   erg/cm2
      90%_error_hi   3.47e-08  3.32e-08  6.10e-08  3.06e-07  1.41e-07  3.56e-07   erg/cm2
Peak flux       PL   3.93e-01  3.72e-01  2.45e-01  2.50e-01  1.11e+00  1.26e+00   ph/cm2/s
      90%_error_low -1.20e-01 -7.99e-02 -6.80e-02 -1.12e-01 -2.34e-01 -2.68e-01   ph/cm2/s
      90%_error_hi   1.28e-01  7.95e-02  6.78e-02  1.54e-01  2.35e-01  2.71e-01   ph/cm2/s
 
Fluence        CPL   2.71e-07  4.09e-07  4.78e-07  1.06e-06  1.49e-06  2.22e-06   erg/cm2
      90%_error_low    N/A    -3.48e-08    N/A       N/A    -1.83e-07 -5.06e-07   erg/cm2
      90%_error_hi     N/A     4.92e-08    N/A       N/A     1.61e-07  3.48e-07   erg/cm2
Peak flux      CPL   3.35e-01  4.42e-01  2.53e-01  5.47e-02  1.07e+00  1.08e+00   ph/cm2/s
      90%_error_low -1.42e-01 -1.13e-01 -1.01e-01 -5.47e-02 -2.42e-01 -2.51e-01   ph/cm2/s
      90%_error_hi   1.46e-01  1.30e-01  8.34e-02  2.45e-01  2.41e-01  2.89e-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
   98.8334    52.3209   0.0105    25.5514   -87.6260         2.4090997     18.413 TRIG_00903845                 
 
Foreground time interval of the image:
-25.544  24.677 (delta_t =  50.221 [sec])
Background time interval of the image:
-162.523 -25.544 (delta_t = 136.979 [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  -25.544 sec. to   31.800 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.78847     ( -0.155141   0.151398 )
Norm@50keV  : 2.79468E-03    ( -0.000258366   0.00025392 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          52.77 using 59 PHA bins.
# Reduced chi-squared =         0.9258 for     57 degrees of freedom 
# Null hypothesis probability =   6.343175e-01
 
Photon flux (15-150 keV)    in 57.34 sec: 0.383412 ( -0.031119  0.03116 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.4761e-06 ( -1.38746e-07  1.4059e-07 ) ergs/cm2
    Cutoff power-law model
    Time interval is from  -25.544 sec. to   31.800 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.79483     ( -0.150979   0.347534 )
Epeak [keV] : 9999.36      ( -9999.35 -9999.36 )
Norm@50keV  : 2.78477E-03    ( -0.00159807   0.0014235 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          52.79 using 59 PHA bins.
# Reduced chi-squared =         0.9426 for     56 degrees of freedom 
# Null hypothesis probability =   5.972676e-01
 
Photon flux (15-150 keV)    in 57.34 sec: 0.383829 ( -0.03174  0.03102 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.4861e-06 ( -1.83268e-07  1.61373e-07 ) ergs/cm2

    1-s peak spectrum fit

    Power-law model
    Time interval is from   -0.388 sec. to    0.612 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.60393     ( -0.34133   0.328515 )
Norm@50keV  : 8.64114E-03    ( -0.00195108   0.00191694 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          47.99 using 59 PHA bins.
# Reduced chi-squared =         0.8419 for     57 degrees of freedom 
# Null hypothesis probability =   7.967163e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.11183 ( -0.234474  0.23466 ) ph/cm2/s
Energy fluence (15-150 keV)             : 8.07811e-08 ( -1.91301e-08  1.95094e-08 ) ergs/cm2
    Cutoff power-law model
    Time interval is from   -0.388 sec. to    0.612 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.148768     ( -1.56902   2.99748 )
Epeak [keV] : 56.1605      ( -15.9804 -56.1457 )
Norm@50keV  : 5.60556E-02    ( -0.0561526   3.034 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          45.69 using 59 PHA bins.
# Reduced chi-squared =         0.8158 for     56 degrees of freedom 
# Null hypothesis probability =   8.358892e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.07430 ( -0.242485  0.2406 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.17811e-08 ( -2.05752e-08  2.2293e-08 ) ergs/cm2

    Time-resolved spectra




    Distribution

    T90 vs. Hardness ratio plot 

    T90                                   = 46.512 sec.
Hardness ratio (energy fluence ratio) = 1.15792361941

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

    S(15-50 keV)  = 6.822634e-07
S(50-150 keV) = 7.938399e-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 = 1.980326264263598E-02, IMY = 4.776668917994986E-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:
-162.523410 -25.544000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
267.3893  63.9465    2.6  56.5   10.4   6.7941   4.5 ------	UNKNOWN                       
123.3264  -1.3397    2.6  55.7 -172.9   6.2197   4.4 ------	UNKNOWN                       
 90.2546  29.0784    3.4  43.9 -116.2   4.2795   3.4 ------	UNKNOWN                       
 77.7853  45.7517    2.3  40.8  -87.7   6.1706   4.9 ------	UNKNOWN

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

    Time interval of the image:
-25.544000 24.676600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
146.3655  -1.0730    2.3  53.5  158.9   3.2931   5.0 ------	UNKNOWN                       
328.8048  70.8447    2.8  56.7  -17.7   1.7817   4.1 ------	UNKNOWN                       
 98.8334  52.3209    0.6  25.6  -87.6   2.4087  18.4 ------	UNKNOWN

    Post-slew image of 15-350 keV band 

    Time interval of the image:
71.676590 710.250400
720.776000 754.276620
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6450  22.0045    0.8  32.5 -128.2  26.3478  14.3    0.9	Crab                          
136.5739  11.9313    2.5  50.4  153.9  32.2741   4.7 ------	UNKNOWN                       
313.3834  68.5382    2.4  56.5   10.4  30.6050   4.9 ------	UNKNOWN                       
 71.3704  15.0635    2.6  43.2 -114.5  26.2297   4.5 ------	UNKNOWN                       
 72.2541  13.9919    2.2  43.8 -116.3  31.0534   5.2 ------	UNKNOWN