Analysis Summary

Notes:

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.46
    Process Start Time: Mon May 20 17:16:22 EDT 2019
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger900285
======================================================================

  Trigger: 00900285      Segment: 000

  BAT Trigger Time: 577792865.984   [s; MET]
      Trigger Stop: 577792867.008   [s; MET]
               UTC: 2019-04-24T10:00:43.191560    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 48.6808760446314   Dec: 20.2334856376405  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    6.72
     Image Trigger?:     NO
     Rate S/N Ratio:     15.1657508881031  [ if not an image trigger ]
     Image S/N Ratio:    6.72

  Analysis Position:   [ source = BAT ]
    RA: 48.6808760446314   Dec: 20.2334856376405  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 48.6932555577323   Dec: 20.2413142171866  [deg; J2000]  
        { 03h 14m 46.4s , +20d 14' 28.7" }
         +/- 1.43103058970632 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.552892855010032 [arcmin] (formal 1-sigma fit error)
    SNR: 18.2289974335155
 
  Angular difference between the analysis and refined position is 0.840432 arcmin
 
  Partial Coding Fraction: 0.4101562    [ including projection effects ]

  Duration
     T90: 9.83599996566772 +/- 3.91796534981675
        Measured from: -0.804000020027161
                   to: 9.03199994564056     [s; relative to TRIGTIME]
     T50: 5.2960000038147 +/- 0.985397294079381
        Measured from: 1.36800003051758
                   to: 6.66400003433228     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 1.09600007534027     
                   to: 2.09600007534027     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -1.31199991703033     
                   to: 14.3680000305176     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.480433   0.720049   0.552130   0.133657
           0.049801   0.053556   0.047571   0.038782 [error]
 Peak      0.044193   0.093931   0.082831   0.021367
           0.012608   0.014186   0.013420   0.011071 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   15.680   -1.312   14.368
T90     9.836   -0.804    9.032
T50     5.296    1.368    6.664
Peak    1.000    1.096    2.096
 
 
====== 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      -1.493    -0.142      0.141       -           -               -         8.12e-03     -6.81e-04          6.78e-04      54.930   57
CPL     -1.197    -0.370      0.611      135.409     -61.298      -135.409      1.15e-02     -3.92e-03          1.16e-02      54.090   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      -1.100     -0.280     0.290       -           -               -         1.72e-02     -2.77e-03          2.76e-03      64.350   57
CPL     -0.870      N/A       N/A         281.263      N/A           N/A         2.19e-02        N/A               N/A         64.320   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   1.62e-07  2.98e-07  4.24e-07  1.27e-06  1.21e-06  2.15e-06   erg/cm2
      90%_error_low -2.22e-08 -2.57e-08 -4.57e-08 -2.68e-07 -1.10e-07 -3.08e-07   erg/cm2
      90%_error_hi   2.30e-08  2.56e-08  4.54e-08  3.13e-07  1.11e-07  3.44e-07   erg/cm2
Peak flux       PL   4.84e-01  6.19e-01  5.78e-01  9.48e-01  2.00e+00  2.63e+00   ph/cm2/s
      90%_error_low -1.50e-01 -1.25e-01 -1.03e-01 -3.19e-01 -3.31e-01 -4.41e-01   ph/cm2/s
      90%_error_hi   1.67e-01  1.21e-01  1.01e-01  4.12e-01  3.33e-01  4.55e-01   ph/cm2/s
 
Fluence        CPL   1.54e-07  3.08e-07  4.32e-07  8.07e-07  1.18e-06  1.70e-06   erg/cm2
      90%_error_low -2.61e-08 -3.13e-08 -4.90e-08 -4.34e-07 -1.22e-07 -4.47e-07   erg/cm2
      90%_error_hi   2.65e-08  3.23e-08  5.00e-08  5.91e-07  1.21e-07  5.75e-07   erg/cm2
Peak flux      CPL   4.68e-01  6.24e-01  5.87e-01  8.25e-01  1.99e+00  2.50e+00   ph/cm2/s
      90%_error_low -1.86e-01 -1.28e-01 -1.10e-01 -5.06e-01 -3.40e-01 -6.44e-01   ph/cm2/s
      90%_error_hi   1.50e-01  1.31e-01  1.25e-01  3.56e-01  3.25e-01  5.44e-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
   48.6933    20.2413   0.0106    33.6996   -74.8538         1.9146232     18.229 TRIG_00900285                 
 
Foreground time interval of the image:
 -1.312  14.368 (delta_t =  15.680 [sec])
Background time interval of the image:
-239.984  -1.312 (delta_t = 238.672 [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   -1.312 sec. to   14.368 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.49329     ( -0.141898   0.14093 )
Norm@50keV  : 8.12291E-03    ( -0.000680606   0.000678017 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          54.93 using 59 PHA bins.
# Reduced chi-squared =         0.9638 for     57 degrees of freedom 
# Null hypothesis probability =   5.529803e-01
 
Photon flux (15-150 keV)    in 15.68 sec: 1.01226 ( -0.084713  0.08482 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.20978e-06 ( -1.10353e-07  1.112e-07 ) ergs/cm2
    Cutoff power-law model
    Time interval is from   -1.312 sec. to   14.368 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.19687     ( -0.369741   0.610924 )
Epeak [keV] : 135.409      ( -61.3085 -135.42 )
Norm@50keV  : 1.15021E-02    ( -0.0039145   0.0116416 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          54.09 using 59 PHA bins.
# Reduced chi-squared =         0.9659 for     56 degrees of freedom 
# Null hypothesis probability =   5.475491e-01
 
Photon flux (15-150 keV)    in 15.68 sec: 1.00055 ( -0.087564  0.08748 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.1842e-06 ( -1.21709e-07  1.20724e-07 ) ergs/cm2

    1-s peak spectrum fit

    Power-law model
    Time interval is from    1.096 sec. to    2.096 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.09966     ( -0.279617   0.290242 )
Norm@50keV  : 1.72483E-02    ( -0.00276909   0.00276043 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          64.35 using 59 PHA bins.
# Reduced chi-squared =          1.129 for     57 degrees of freedom 
# Null hypothesis probability =   2.348955e-01
 
Photon flux (15-150 keV)    in 1 sec: 2.00062 ( -0.33115  0.33288 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.80372e-07 ( -3.11338e-08  3.13568e-08 ) ergs/cm2
    Cutoff power-law model
    Time interval is from    1.096 sec. to    2.096 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.02645     (       )
Epeak [keV] : 9.66330      (   )
Norm@50keV  : 3.46717E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          64.27 using 59 PHA bins.
# Reduced chi-squared =          1.148 for     56 degrees of freedom 
# Null hypothesis probability =   2.094573e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.98973 ( -0.33994  0.32511 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.79374e-07 ( -3.22952e-08  3.09409e-08 ) ergs/cm2

    Time-resolved spectra




    Distribution

    T90 vs. Hardness ratio plot 

    T90                                   = 9.836 sec.
Hardness ratio (energy fluence ratio) = 1.42085602565

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

    S(15-50 keV)  = 4.59805e-07
S(50-150 keV) = 7.499646e-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 = 1.742514579650881E-01, IMY = 6.437401024430686E-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:
-239.984000 -1.312000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6395  22.0249    0.4   5.4   -0.8  10.0435  26.4    0.7	Crab                          
120.2143  -2.4021    3.7  40.4  118.1   5.9760   3.1 ------	UNKNOWN                       
 65.5192 -13.1830    2.8  35.0 -143.9   2.3908   4.1 ------	UNKNOWN

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

    Time interval of the image:
-1.312000 14.368000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.7841  22.1733    0.0   5.6    0.7   0.0343   0.6   12.7	Crab                          
 54.7496  73.2885    1.9  59.1   -6.0   2.2338   6.1 ------	UNKNOWN                       
 48.6933  20.2413    0.6  33.7  -74.9   1.9144  18.2 ------	UNKNOWN                       
 47.4004 -10.8345    2.0  45.5 -121.2   1.3821   5.7 ------	UNKNOWN

    Post-slew image of 15-350 keV band 

    Time interval of the image:
179.516600 962.126600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.5631 -40.5038    1.6  13.3  -90.5   8.9327   7.1    3.4	Vela X-1                      
170.6881 -60.6952    3.5  24.9  172.5   4.6091   3.3   11.8	Cen X-3                       
186.7751 -62.8057    3.5  31.9  164.5   5.6270   3.3    3.9	GX 301-2                      
204.2980 -36.9431    3.1  40.4  118.1  20.0608   3.7 ------	UNKNOWN                       
221.6208 -61.1036    2.5  47.1  155.6  22.9137   4.6 ------	UNKNOWN                       
145.0613  15.0143    3.0  54.0    4.6  11.3305   3.9 ------	UNKNOWN                       
142.2254  -4.9751    2.9  34.8   -4.7   6.5360   4.0 ------	UNKNOWN                       
126.1629 -24.5581    2.4  26.3  -52.3   6.9902   4.9 ------	UNKNOWN                       
124.3811   1.0507    3.2  47.3  -26.4   8.4050   3.6 ------	UNKNOWN                       
 98.2996 -42.7775    2.4  40.7 -100.4  27.5892   4.8 ------	UNKNOWN                       
 91.2153 -52.8490    2.0  43.8 -116.3  31.1127   5.6 ------	UNKNOWN