GRB200907B: Summary Image Light curves Spectra Distribution Others

Analysis Summary

Notes:

• 1) No attempt has been made to eliminate the non-significant decimal places.
• 2) This batgrbproduct analysis is done using the HEASARC data.
• 3) This batgrbproduct analysis is using the flight position for the mask-weighting calculation.

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.48
    Process Start Time: Wed Oct 19 23:47:22 EDT 2022
             Host Name: batproc1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger995004
======================================================================

  Trigger: 00995004      Segment: 000

  BAT Trigger Time: 621197496.768   [s; MET]
      Trigger Stop: 621197497.024   [s; MET]
               UTC: 2020-09-07T18:51:11.173040    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 89.0132987196125   Dec: 6.9106310534709  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    9.45
     Image Trigger?:     NO
     Rate S/N Ratio:     23.4093998214393  [ if not an image trigger ]
     Image S/N Ratio:    9.45

  Analysis Position:   [ source = BAT ]
    RA: 89.0132987196125   Dec: 6.9106310534709  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 89.0186661880718   Dec: 6.90493001644181  [deg; J2000]  
        { 05h 56m 04.5s , +06d 54' 17.7" }
         +/- 1.83306134109208 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.859541821129795 [arcmin] (formal 1-sigma fit error)
    SNR: 12.7982691588517
 
  Angular difference between the analysis and refined position is 0.468211 arcmin
 
  Partial Coding Fraction: 0.7890625    [ including projection effects ]

  Duration
     T90: 0.832000017166138 +/- 0.133880554639642
        Measured from: -0.572000026702881
                   to: 0.259999990463257     [s; relative to TRIGTIME]
     T50: 0.447999954223633 +/- 0.123693125978031
        Measured from: -0.324000000953674
                   to: 0.123999953269958     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.675999999046326     
                   to: 0.324000000953674     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.639999985694885     
                   to: 0.284000039100647     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.035949   0.051848   0.073322   0.046492
           0.007723   0.008401   0.008137   0.007118 [error]
 Peak      0.034700   0.053882   0.076359   0.046571
           0.007986   0.008730   0.008343   0.007366 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100    0.924   -0.640    0.284
T90     0.832   -0.572    0.260
T50     0.448   -0.324    0.124
Peak    1.000   -0.676    0.324
 
 
====== 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: 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      -0.680    -0.244      0.264       -           -               -         1.38e-02     -2.00e-03          1.92e-03      40.310   57
CPL     -0.680    -0.238      0.275     9999.360    -9999.360      -9999.360      1.39e-02     -1.86e-03          7.36e-03      40.350   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      -0.637     -0.243     0.263       -           -               -         1.29e-02     -1.92e-03          1.85e-03      43.970   57
CPL     -0.550     -0.334     0.662      999.046    -999.046      -999.046      1.41e-02     -2.83e-03          8.53e-03      44.240   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   7.60e-09  2.32e-08  5.79e-08  4.09e-07  1.57e-07  4.97e-07   erg/cm2
      90%_error_low -2.31e-09 -4.45e-09 -7.37e-09 -1.18e-07 -2.05e-08 -1.20e-07   erg/cm2
      90%_error_hi   2.62e-09  4.33e-09  7.31e-09  1.54e-07  2.06e-08  1.53e-07   erg/cm2
Peak flux       PL   2.34e-01  3.96e-01  5.10e-01  1.32e+00  1.50e+00  2.46e+00   ph/cm2/s
      90%_error_low -7.31e-02 -8.05e-02 -6.33e-02 -3.48e-01 -1.99e-01 -3.59e-01   ph/cm2/s
      90%_error_hi   8.41e-02  7.94e-02  6.32e-02  4.37e-01  2.01e-01  3.99e-01   ph/cm2/s
 
Fluence        CPL   7.58e-09  2.32e-08  5.80e-08  4.13e-07  1.57e-07  4.82e-07   erg/cm2
      90%_error_low    N/A    -4.46e-09    N/A    -2.02e-07    N/A    -1.70e-07   erg/cm2
      90%_error_hi     N/A     4.33e-09    N/A     1.56e-07    N/A     1.62e-07   erg/cm2
Peak flux      CPL   2.34e-01  3.99e-01  5.09e-01  1.42e+00  1.51e+00  2.52e+00   ph/cm2/s
      90%_error_low     N/A       N/A       N/A   -6.77e-01     N/A   -7.36e-01   ph/cm2/s
      90%_error_hi      N/A       N/A       N/A    4.40e-01     N/A    3.64e-01   ph/cm2/s
 
======================================================================

Image

Pre-slew 15.0-350.0 keV image (Event data)

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
   89.0187     6.9049   0.0150    23.5826   149.2167         0.2066859     12.798 TRIG_00995004                 
 
Foreground time interval of the image:
 -0.640   0.284 (delta_t =   0.924 [sec])
Background time interval of the image:
-239.768  -0.640 (delta_t = 239.128 [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

Other quick-look light curves:

• 64 ms binning (zoomed)
• 16 ms binning (zoomed)
• 8 ms binning (zoomed)
• 2 ms binning (zoomed)
• SN=5 or 10 s binning (full-time range)
• Raw light curve

Spectra

Notes:

• 1) The fitting includes the systematic errors.
• 2) When the burst includes telescope slew time periods, the fitting uses an average response file made from multiple 5-s response files through out the slew time plus single time preiod for the non-slew times, and weighted by the total counts in the corresponding time period using addrmf. An average response file is needed becuase a spectral fit using the pre-slew DRM will introduce some errors in both a spectral shape and a normalization if the PHA file contains a lot of the slew/post-slew time interval.
• 3) For fits to more complicated models (e.g. a power-law over a cutoff power-law), the BAT team has decided to require a chi-square improvement of more than 6 for each extra dof.

Time averaged spectrum fit using the average DRM

Power-law model

Time interval is from   -0.640 sec. to    0.284 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.679718     ( -0.244503   0.263759 )
Norm@50keV  : 1.38031E-02    ( -0.00199794   0.001923 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   40.31     using 59 bins.
 Reduced chi-squared = 0.707193
# Null hypothesis probability of 9.54e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 0.924 sec: 1.59818 ( -0.21042  0.21135 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.57142e-07 ( -2.05415e-08  2.05722e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -0.640 sec. to    0.284 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.68011     ( -0.238497   0.274924 )
Epeak [keV] : 9999.36      ( -9999.36 -9999.36 )
Norm@50keV  : 1.39431E-02    ( -0.00185433   0.00736631 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   40.35     using 59 bins.
 Reduced chi-squared = 0.720536
# Null hypothesis probability of 9.43e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 0.924 sec: 1.59768 ( -0.21049  0.21121 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.57066e-07 ( 0  0 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   -0.676 sec. to    0.324 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.636501     ( -0.243258   0.263498 )
Norm@50keV  : 1.29407E-02    ( -0.0019213   0.00184716 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   43.97     using 59 bins.
 Reduced chi-squared = 0.771404
# Null hypothesis probability of 8.97e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 1.50460 ( -0.19948  0.2006 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.6266e-07 ( -2.11165e-08  2.11546e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -0.676 sec. to    0.324 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.6273     ( -0.333849   0.66186 )
Epeak [keV] : 9999.35      ( -9999.36 -9999.36 )
Norm@50keV  : 1.30420E-02    ( -0.00177689   0.00958245 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   43.99     using 59 bins.
 Reduced chi-squared = 0.785536
# Null hypothesis probability of 8.78e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 1.51491 (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.62619e-07 ( -2.11146e-08  2.11575e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = N/A sec.
Hardness ratio (energy fluence ratio) = N/A

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

S(15-50 keV)  = N/A
S(50-150 keV) = N/A

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 = -3.750242461204163E-01, IMY = -2.234109063977873E-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:
-239.768000 -0.640000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6246  22.0214    0.5  38.1  162.5  10.0430  22.6    0.6	Crab                          
135.5163 -40.5616    0.9  40.9  -14.9   5.1852  13.1    0.7	Vela X-1                      
133.7143 -31.6969    3.3  34.0  -24.5   1.1604   3.5 ------	UNKNOWN                       
135.1554  -1.6035    3.0  29.0  -83.4   1.6617   3.8 ------	UNKNOWN                       
145.1719 -25.0569    2.4  40.0  -42.0   2.1697   4.9 ------	UNKNOWN                       
150.4771 -33.9376    2.4  47.4  -32.2   2.7769   4.7 ------	UNKNOWN                       
141.4932 -12.4832    3.0  34.2  -61.5   1.6880   3.9 ------	UNKNOWN                       

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

Time interval of the image:
-0.640000 0.284000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.4922  22.0262    6.3  38.2  162.3   0.0395   1.8    7.9	Crab                          
135.4960 -40.6077    5.4  40.9  -14.8   0.0427   2.2    3.5	Vela X-1                      
 89.0187   6.9049    0.9  23.6  149.2   0.2067  12.8 ------	UNKNOWN                       
122.4411 -58.5859    1.9  51.4    8.6   0.2353   6.1 ------	UNKNOWN                       
 88.3929  46.2912    2.4  57.3 -176.3   0.3889   4.8 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
63.732600 837.132600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6281  22.0187    0.3  16.0  166.0  30.8433  44.0    0.4	Crab