GRB190821A: 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 v2.46
    Process Start Time: Tue Oct  8 22:29:04 EDT 2019
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger921722
======================================================================

  Trigger: 00921722      Segment: 000

  BAT Trigger Time: 588100227.328   [s; MET]
      Trigger Stop: 588100228.736   [s; MET]
               UTC: 2019-08-21T17:10:03.878460    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 250.076946712462   Dec: -34.0215900580302  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    8.8
     Image Trigger?:     NO
     Rate S/N Ratio:     11.2694276695846  [ if not an image trigger ]
     Image S/N Ratio:    8.8

  Analysis Position:   [ source = BAT ]
    RA: 250.076946712462   Dec: -34.0215900580302  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 250.070237617101   Dec: -34.0265150241703  [deg; J2000]  
        { 16h 40m 16.9s , -34d 01' 35.5" }
         +/- 1.32633023350204 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.501644181127196 [arcmin] (formal 1-sigma fit error)
    SNR: 20.3189709488097
 
  Angular difference between the analysis and refined position is 0.445678 arcmin
 
  Partial Coding Fraction: 0.8359375    [ including projection effects ]

  Duration
     T90: 57.095999956131 +/- 2.59615098282311
        Measured from: -1.07199990749359
                   to: 56.0240000486374     [s; relative to TRIGTIME]
     T50: 32.6839998960495 +/- 2.39003606412485
        Measured from: 12.2800000905991
                   to: 44.9639999866486     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 29.9840000867844     
                   to: 30.9840000867844     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -3.30799996852875     
                   to: 59.4920001029968     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     1.675078   1.744593   0.888540   0.179323
           0.075674   0.068286   0.055942   0.045411 [error]
 Peak      0.111102   0.146155   0.068012   0.007259
           0.011115   0.011109   0.008806   0.006062 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   62.800   -3.308   59.492
T90    57.096   -1.072   56.024
T50    32.684   12.280   44.964
Peak    1.000   29.984   30.984
 
 
====== 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      -2.014    -0.098      0.096       -           -               -         4.07e-03     -2.30e-04          2.28e-04      60.300   57
CPL     -1.596    -0.395      0.439       43.438     -35.616        21.646      6.83e-03     -2.60e-03          4.88e-03      57.030   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      -1.937     -0.163     0.156       -           -               -         1.94e-02     -2.15e-03          2.12e-03      63.370   57
CPL     -0.384     -0.820     1.031       44.420      -6.146         8.704      1.47e-01     -1.47e-01          4.28e-01      51.080   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   5.29e-07  7.12e-07  7.06e-07  1.26e-06  2.36e-06  3.21e-06   erg/cm2
      90%_error_low -4.19e-08 -3.48e-08 -5.53e-08 -1.94e-07 -1.26e-07 -2.48e-07   erg/cm2
      90%_error_hi   4.29e-08  3.48e-08  5.57e-08  2.18e-07  1.27e-07  2.64e-07   erg/cm2
Peak flux       PL   1.22e+00  9.45e-01  4.94e-01  3.73e-01  2.82e+00  3.03e+00   ph/cm2/s
      90%_error_low -1.62e-01 -8.92e-02 -6.99e-02 -9.13e-02 -2.69e-01 -2.86e-01   ph/cm2/s
      90%_error_hi   1.66e-01  8.92e-02  7.04e-02  1.07e-01  2.69e-01  2.87e-01   ph/cm2/s
 
Fluence        CPL   4.99e-07  7.41e-07  7.02e-07  6.47e-07  2.26e-06  2.59e-06   erg/cm2
      90%_error_low -5.03e-08 -4.36e-08 -5.99e-08 -2.84e-07 -1.53e-07 -3.32e-07   erg/cm2
      90%_error_hi   5.10e-08  4.44e-08  5.92e-08  5.59e-07  1.54e-07  5.79e-07   erg/cm2
Peak flux      CPL   1.03e+00  1.12e+00  4.93e-01  7.47e-02  2.70e+00  2.71e+00   ph/cm2/s
      90%_error_low -1.91e-01 -1.26e-01 -9.18e-02 -4.70e-02 -2.75e-01 -2.80e-01   ph/cm2/s
      90%_error_hi   1.93e-01  1.31e-01  8.71e-02  9.32e-02  2.75e-01  2.85e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  250.0702   -34.0265   0.0095    22.2724  -122.7599         1.7398844     20.319 TRIG_00921722                 
 
Foreground time interval of the image:
 -3.308  23.973 (delta_t =  27.281 [sec])
Background time interval of the image:
-239.328  -3.308 (delta_t = 236.020 [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   -3.308 sec. to   59.492 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.01396     ( -0.0981079   0.0962671 )
Norm@50keV  : 4.06577E-03    ( -0.000229902   0.000227735 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          60.30 using 59 PHA bins.
# Reduced chi-squared =          1.058 for     57 degrees of freedom 
# Null hypothesis probability =   3.572823e-01
 
Photon flux (15-150 keV)    in 62.8 sec: 0.613859 ( -0.031495  0.03159 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.35689e-06 ( -1.2589e-07  1.26698e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -3.308 sec. to   59.492 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.59588     ( -0.395014   0.438579 )
Epeak [keV] : 43.4382      ( -35.6157 21.6463 )
Norm@50keV  : 6.83354E-03    ( -0.00259982   0.004878 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          57.03 using 59 PHA bins.
# Reduced chi-squared =          1.018 for     56 degrees of freedom 
# Null hypothesis probability =   4.365184e-01
 
Photon flux (15-150 keV)    in 62.8 sec: 0.597380 ( -0.034884  0.035009 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.26022e-06 ( -1.53045e-07  1.54409e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   29.984 sec. to   30.984 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.9373     ( -0.162982   0.156293 )
Norm@50keV  : 1.93656E-02    ( -0.00215357   0.0021229 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          63.37 using 59 PHA bins.
# Reduced chi-squared =          1.112 for     57 degrees of freedom 
# Null hypothesis probability =   2.617972e-01
 
Photon flux (15-150 keV)    in 1 sec: 2.82442 ( -0.26856  0.26872 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.7818e-07 ( -1.91826e-08  1.94077e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   29.984 sec. to   30.984 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.383848     ( -0.822581   1.02824 )
Epeak [keV] : 44.4200      ( -6.13584 8.71384 )
Norm@50keV  : 0.147057    ( -0.147829   0.427552 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          51.08 using 59 PHA bins.
# Reduced chi-squared =         0.9122 for     56 degrees of freedom 
# Null hypothesis probability =   6.610400e-01
 
Photon flux (15-150 keV)    in 1 sec: 2.70333 ( -0.27472  0.27546 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.59948e-07 ( -1.95762e-08  2.07278e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 57.096 sec.
Hardness ratio (energy fluence ratio) = 0.990397839296

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

S(15-50 keV)  = 1.2418162e-06
S(50-150 keV) = 1.1150634e-06

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 = -2.216252074017614E-01, IMY = 3.444242243999509E-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:
-239.328000 -3.308000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
245.0015 -15.6279    0.8  26.0  -76.1   9.3189  14.6    1.5	Sco X-1                       
255.9842 -37.8451    5.7  20.6 -138.9   0.9916   2.0    0.1	4U 1700-377                   
256.3453 -36.5630  387.5  19.5 -136.8   0.0147   0.0    9.5	GX 349+2                      
262.9121 -24.7091    3.7   8.3 -105.1   1.4803   3.1    5.7	GX 1+4                        
264.8389 -44.5178   10.9  23.0 -163.7   0.5023   1.1    5.8	4U 1735-44                    
268.2354  -1.6110    0.0  20.9   -5.6  -0.5874  -1.2   12.4	SW J1753.5-0127               
270.4484 -25.0566    8.3   3.0 -155.9   0.6339   1.4    9.0	GX 5-1                        
270.1350 -25.7272    4.6   3.7 -155.5   1.1527   2.5    9.1	GRS 1758-258                  
274.1603 -14.0459    3.9   8.5   20.9   1.4469   2.9    9.0	GX 17+2                       
275.9575 -30.2715    5.8   8.9  158.9   0.9425   2.0    6.0	H1820-303                     
285.1021 -24.9975   18.6  12.7  109.1  -0.3103  -0.6    5.9	HT1900.1-2455                 
288.7646  11.0275   13.5  37.3   32.5   0.6361   0.9    5.3	GRS 1915+105                  
262.8893 -33.9818    4.0  14.0 -144.9   1.2115   2.9   10.1	GX 354-0                      
314.7585 -53.1513    2.6  44.9  148.4   7.9747   4.5 ------	UNKNOWN                       
320.9730 -62.6852    2.4  52.2  157.7  14.1581   4.7 ------	UNKNOWN                       
261.2987   3.7578    2.2  27.9  -18.5   2.8155   5.2 ------	UNKNOWN                       
249.5033  15.9667    2.4  43.9  -27.5   3.7443   4.8 ------	UNKNOWN                       
227.9967 -60.7343    2.2  48.9 -149.5   6.6771   5.3 ------	UNKNOWN                       

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

Time interval of the image:
-3.308000 23.972600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
244.8400 -15.6593    9.4  26.1  -76.2   0.1282   1.2    8.1	Sco X-1                       
256.0348 -37.9242    7.1  20.6 -139.2  -0.1364  -1.6    5.3	4U 1700-377                   
256.3308 -36.2685    5.6  19.3 -136.1   0.1728   2.1   10.6	GX 349+2                      
262.9213 -24.5974    5.6   8.3 -104.3   0.1599   2.0   10.1	GX 1+4                        
264.9419 -44.5627   10.1  23.0 -163.9  -0.0970  -1.1   10.9	4U 1735-44                    
268.4457  -1.5979    3.7  20.9   -5.0  -0.2575  -3.1    9.9	SW J1753.5-0127               
270.1286 -25.2374    0.0   3.3 -152.3  -0.0396  -0.5   12.7	GX 5-1                        
270.4362 -25.6402    6.1   3.6 -159.0   0.1717   2.2    9.5	GRS 1758-258                  
273.9986 -14.0569  192.4   8.5   19.9   0.0047   0.1    1.3	GX 17+2                       
276.0726 -30.4262    4.9   9.1  158.8   0.1845   2.4    8.4	H1820-303                     
284.8981 -25.0907    0.0  12.5  109.7  -0.1101  -1.3   12.7	HT1900.1-2455                 
288.6584  10.9726    6.7  37.2   32.3  -0.2602  -1.7    8.4	GRS 1915+105                  
262.8858 -33.6846    4.9  13.8 -144.2   0.1876   2.3   10.4	GX 354-0                      
309.6830 -23.3528    2.2  35.0  103.2   1.0278   5.3 ------	UNKNOWN                       
250.0702 -34.0265    0.6  22.3 -122.8   1.7401  20.3 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
67.172600 428.572600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
170.1816 -60.7563    5.3  56.0 -149.2  -8.0238  -2.2    8.9	Cen X-3                       
186.4882 -62.6870    9.0  48.2 -151.2   2.1819   1.3    6.8	GX 301-2                      
244.9896 -15.6256    0.5  18.9  -20.0  16.0448  22.9    1.1	Sco X-1                       
255.7956 -37.8851    5.8   6.0  127.1   1.3586   2.0    9.4	4U 1700-377                   
256.6249 -36.2760    0.0   5.8  110.3   2.2756   3.3   12.7	GX 349+2                      
262.9422 -24.7089    7.5  14.5   48.9   1.0214   1.5    4.3	GX 1+4                        
264.9266 -44.2890    8.2  15.4  131.7   1.0442   1.4   12.5	4U 1735-44                    
268.4911  -1.4128    9.5  36.8   27.1  -1.2972  -1.2    7.8	SW J1753.5-0127               
270.3922 -25.1934   78.0  19.7   64.1  -0.1294  -0.2    9.0	GX 5-1                        
270.2987 -25.7071    7.5  19.3   65.3   1.5722   1.8    2.2	GRS 1758-258                  
274.1591 -14.0670   13.7  29.5   48.7   0.9487   0.8    9.1	GX 17+2                       
276.0392 -30.2112    4.8  22.2   82.7   2.1322   2.4   11.1	H1820-303                     
284.8382 -24.8238    0.0  31.4   77.7   1.7881   1.4   12.2	HT1900.1-2455                 
263.1778 -33.9751    0.0  10.8   88.9   1.0200   1.4   12.6	GX 354-0                      
303.9486 -66.5918    2.8  45.0  148.3  11.1252   4.2 ------	UNKNOWN                       
216.0343 -77.8048    2.6  46.2 -175.2   6.5893   4.4 ------	UNKNOWN                       
195.4167 -37.9789    2.4  43.8 -116.3  13.2498   4.7 ------	UNKNOWN