GRB210618A: 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: Fri Jul 29 23:03:09 EDT 2022
             Host Name: batproc1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1056426
======================================================================

  Trigger: 01056426      Segment: 000

  BAT Trigger Time: 645673444.224   [s; MET]
      Trigger Stop: 645673444.736   [s; MET]
               UTC: 2021-06-18T01:43:37.008340    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 235.820334978217   Dec: 46.0433632334042  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.01
     Image Trigger?:     NO
     Rate S/N Ratio:     12.369316876853  [ if not an image trigger ]
     Image S/N Ratio:    7.01

  Analysis Position:   [ source = BAT ]
    RA: 235.820334978217   Dec: 46.0433632334042  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 235.76357055125   Dec: 46.0686421956418  [deg; J2000]  
        { 15h 43m 03.3s , +46d 04' 07.1" }
         +/- 2.01107368901802 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.936196155566632 [arcmin] (formal 1-sigma fit error)
    SNR: 11.2111414279785
 
  Angular difference between the analysis and refined position is 2.808328 arcmin
 
  Partial Coding Fraction: 1.015625    [ including projection effects ]

  Duration
     T90: 2.13199996948242 +/- 0.438488315161259
        Measured from: -1.3639999628067
                   to: 0.76800000667572     [s; relative to TRIGTIME]
     T50: 1.25599992275238 +/- 0.515503641776127
        Measured from: -0.916000008583069
                   to: 0.339999914169312     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.495999932289124     
                   to: 0.504000067710876     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -1.41999995708466     
                   to: 0.927999973297119     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.059160   0.100822   0.072310   0.034526
           0.011647   0.012911   0.013016   0.014175 [error]
 Peak      0.035203   0.055008   0.045402   0.014324
           0.007656   0.008703   0.008684   0.009359 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100    2.348   -1.420    0.928
T90     2.132   -1.364    0.768
T50     1.256   -0.916    0.340
Peak    1.000   -0.496    0.504
 
 
====== 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      -1.216    -0.277      0.278       -           -               -         7.27e-03     -1.11e-03          1.10e-03      58.670   57
CPL     -1.193    -2.586      0.890     9980.860    -9980.860      -9980.860      7.49e-03     -1.30e-03          1.37e-02      58.750   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      -1.136     -0.327     0.334       -           -               -         9.66e-03     -1.72e-03          1.71e-03      89.460   57
CPL     -1.140     -0.321     0.344     9999.360    -9999.360      -9999.360      9.68e-03     -1.67e-03          1.55e-02      89.470   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   1.67e-08  3.66e-08  6.30e-08  2.51e-07  1.72e-07  3.67e-07   erg/cm2
      90%_error_low -4.27e-09 -5.73e-09 -1.28e-08 -9.60e-08 -3.14e-08 -1.07e-07   erg/cm2
      90%_error_hi   4.53e-09  5.65e-09  1.27e-08  1.34e-07  3.24e-08  1.41e-07   erg/cm2
Peak flux       PL   2.81e-01  3.51e-01  3.20e-01  5.06e-01  1.13e+00  1.46e+00   ph/cm2/s
      90%_error_low -8.83e-02 -6.92e-02 -7.22e-02 -2.07e-01 -1.96e-01 -2.91e-01   ph/cm2/s
      90%_error_hi   9.56e-02  6.73e-02  7.09e-02  2.94e-01  1.96e-01  3.20e-01   ph/cm2/s
 
Fluence        CPL   1.67e-08  3.62e-08  6.27e-08  2.66e-07  1.76e-07  3.70e-07   erg/cm2
      90%_error_low    N/A    -5.76e-09    N/A    -2.11e-07 -4.00e-08 -2.02e-07   erg/cm2
      90%_error_hi     N/A     6.70e-09    N/A     4.96e-08  1.76e-08  6.04e-08   erg/cm2
Peak flux      CPL   2.87e-01  3.51e-01  3.18e-01  5.10e-01  1.13e+00  1.46e+00   ph/cm2/s
      90%_error_low -9.66e-02 -6.91e-02 -7.08e-02     N/A   -2.26e-01 -4.02e-01   ph/cm2/s
      90%_error_hi   9.05e-02  6.79e-02  7.37e-02     N/A    2.09e-01  2.90e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  235.7636    46.0686   0.0172    13.1367  -156.5186         0.3045533     11.211 TRIG_01056426                 
 
Foreground time interval of the image:
 -1.420   0.928 (delta_t =   2.348 [sec])
Background time interval of the image:
-119.224  -1.420 (delta_t = 117.804 [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   -1.420 sec. to    0.928 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.21642     ( -0.277341   0.277633 )
Norm@50keV  : 7.27312E-03    ( -0.0011086   0.00109778 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   58.67     using 59 bins.
 Reduced chi-squared = 1.0293
# Null hypothesis probability of 4.14e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 2.348 sec: 0.855746 ( -0.125859  0.125866 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.72484e-07 ( -3.13639e-08  3.23533e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -1.420 sec. to    0.928 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.19306     ( -2.57022   0.905237 )
Epeak [keV] : 9980.86      ( -9999.34 -9999.34 )
Norm@50keV  : 7.48632E-03    ( -0.00111629   0.0138709 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   58.75     using 59 bins.
 Reduced chi-squared = 1.04911
# Null hypothesis probability of 3.75e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 2.348 sec: 0.862351 ( -0.160819  0.146439 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.75723e-07 ( -3.99857e-08  1.75801e-08 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   -0.496 sec. to    0.504 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.13629     ( -0.327105   0.334275 )
Norm@50keV  : 9.66315E-03    ( -0.00171649   0.00170542 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   89.46     using 59 bins.
 Reduced chi-squared = 1.56947
# Null hypothesis probability of 3.89e-03 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 1.12513 ( -0.196245  0.19627 ) ph/cm2/s
Energy fluence (15-150 keV)             : 9.9901e-08 ( -2.12942e-08  2.20092e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -0.496 sec. to    0.504 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.13986     ( -0.321894   0.343868 )
Epeak [keV] : 9999.36      ( -9999.36 -9999.36 )
Norm@50keV  : 9.67663E-03    ( -0.00170019   0.0154577 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   89.47     using 59 bins.
 Reduced chi-squared = 1.59768
# Null hypothesis probability of 2.98e-03 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 1.13193 ( -0.22569  0.20852 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.43596e-08 ( -1.76194e-08  8.47109e-09 ) 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 = -2.140563135164859E-01, IMY = 9.299182024394913E-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:
-119.224000 -1.420000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.4493  35.3399   77.7   9.7  102.4   0.0461   0.1    0.4	Her X-1                       
288.6581  10.8009   40.3  45.0   50.9  -0.2916  -0.3   12.0	GRS 1915+105                  
299.5846  35.1188    1.7  35.4   12.3   2.9838   6.7    5.0	Cyg X-1                       
308.3552  40.9913    0.0  38.9   -1.6   0.6659   1.5   11.3	Cyg X-3                       
326.3185  38.3400   12.4  52.3   -7.5  -0.7147  -0.9    7.0	Cyg X-2                       
241.1548   9.0906    3.1  37.7  124.0   2.9305   3.8 ------	UNKNOWN                       
318.9088  23.8788    3.7  55.6   11.7   5.4290   3.1 ------	UNKNOWN                       
294.6457  35.7818    2.9  31.6   14.9   1.4473   4.0 ------	UNKNOWN                       
215.2193  28.1630    2.6  35.3  177.2   1.7232   4.4 ------	UNKNOWN                       
195.4721  14.3918    3.3  58.1 -179.9   7.5448   3.6 ------	UNKNOWN                       
187.1990  23.8385    3.1  57.6 -165.4   4.9256   3.7 ------	UNKNOWN                       
320.7240  57.9156    2.4  41.4  -30.5   2.3735   4.8 ------	UNKNOWN                       

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

Time interval of the image:
-1.420000 0.928000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.2405  35.4579    0.0   9.5  103.4  -0.0189  -0.7   12.7	Her X-1                       
288.8558  10.8641    6.7  45.0   50.6   0.2047   1.7    5.9	GRS 1915+105                  
299.5658  35.2697    4.9  35.3   12.1   0.0922   2.3    4.3	Cyg X-1                       
308.0301  41.1132    4.5  38.6   -1.6  -0.1058  -2.6   10.3	Cyg X-3                       
326.2174  38.4165    4.0  52.2   -7.5   0.1975   2.9    6.1	Cyg X-2                       
235.7636  46.0686    1.0  13.1 -156.5   0.3045  11.2 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
49.276600 258.876610
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.5142  35.2525   12.3  17.7   60.3  -0.3420  -0.9    6.1	Her X-1                       
299.5765  35.1840    1.2  48.3   18.7   7.8622   9.7    1.3	Cyg X-1                       
308.1805  41.0355   19.5  50.8    7.4  -0.5093  -0.6    5.9	Cyg X-3                       
189.6407  28.9797    2.6  39.7 -159.5   2.2190   4.6 ------	UNKNOWN                       
178.7160  13.5939    3.6  57.6 -165.4   5.5054   3.2 ------	UNKNOWN                       
341.9789  61.1422    2.9  57.5  -27.2   7.4520   3.9 ------	UNKNOWN