GRB200909B: 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 23:45:42 EDT 2022
             Host Name: batproc1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger995288
======================================================================

  Trigger: 00995288      Segment: 000

  BAT Trigger Time: 621386256.064   [s; MET]
      Trigger Stop: 621386257.088   [s; MET]
               UTC: 2020-09-09T23:17:10.456620    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 175.17575805061   Dec: -31.1790605147067  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.51
     Image Trigger?:     NO
     Rate S/N Ratio:     13.1529464379659  [ if not an image trigger ]
     Image S/N Ratio:    7.51

  Analysis Position:   [ source = BAT ]
    RA: 175.17575805061   Dec: -31.1790605147067  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 175.174539786638   Dec: -31.2029207996047  [deg; J2000]  
        { 11h 40m 41.9s , -31d 12' 10.5" }
         +/- 1.4053230059855 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.454525600113584 [arcmin] (formal 1-sigma fit error)
    SNR: 18.707234304325
 
  Angular difference between the analysis and refined position is 1.432982 arcmin
 
  Partial Coding Fraction: 0.359375    [ including projection effects ]

  Duration
     T90: 13.703999876976 +/- 2.16713637717744
        Measured from: -4.83599996566772
                   to: 8.86799991130829     [s; relative to TRIGTIME]
     T50: 6.26800000667572 +/- 1.27188056188019
        Measured from: -2.20800006389618
                   to: 4.05999994277954     [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: -5.60000002384186     
                   to: 10.3559999465942     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.460565   0.616261   0.503527   0.127805
           0.045324   0.048386   0.042717   0.035206 [error]
 Peak      0.038595   0.040750   0.068220   0.022164
           0.011564   0.012795   0.011766   0.008929 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   15.956   -5.600   10.356
T90    13.704   -4.836    8.868
T50     6.268   -2.208    4.060
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: 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      -1.569    -0.137      0.135       -           -               -         7.37e-03     -6.26e-04          6.23e-04      57.740   57
CPL     -0.828    -0.560      0.645       77.555     -17.063        82.308      1.78e-02     -8.47e-03          1.97e-02      52.410   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      -1.399     -0.394     0.382       -           -               -         1.12e-02     -2.52e-03          2.51e-03      47.160   57
CPL     -1.204     -1.757     1.966      236.558    -236.558      -236.558      1.37e-02     -1.37e-02          6.99e-02      47.130   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   1.60e-07  2.82e-07  3.80e-07  1.05e-06  1.10e-06  1.88e-06   erg/cm2
      90%_error_low -2.10e-08 -2.40e-08 -4.14e-08 -2.20e-07 -1.00e-07 -2.59e-07   erg/cm2
      90%_error_hi   2.17e-08  2.39e-08  4.12e-08  2.54e-07  1.01e-07  2.85e-07   erg/cm2
Peak flux       PL   4.19e-01  4.48e-01  3.39e-01  4.19e-01  1.37e+00  1.63e+00   ph/cm2/s
      90%_error_low -1.59e-01 -1.14e-01 -9.27e-02 -1.96e-01 -3.17e-01 -3.67e-01   ph/cm2/s
      90%_error_hi   1.79e-01  1.11e-01  8.91e-02  2.66e-01  3.18e-01  3.70e-01   ph/cm2/s
 
Fluence        CPL   1.43e-07  3.06e-07  3.97e-07  3.93e-07  1.05e-06  1.24e-06   erg/cm2
      90%_error_low -2.49e-08 -3.02e-08 -4.64e-08 -1.91e-07 -1.08e-07 -2.18e-07   erg/cm2
      90%_error_hi   2.52e-08  3.11e-08  4.70e-08  4.10e-07  1.09e-07  4.11e-07   erg/cm2
Peak flux      CPL   4.02e-01  4.53e-01  3.48e-01  3.64e-01  1.36e+00  1.57e+00   ph/cm2/s
      90%_error_low -2.27e-01 -1.18e-01 -9.98e-02 -3.64e-01 -3.28e-01 -4.69e-01   ph/cm2/s
      90%_error_hi   1.92e-01  1.25e-01  1.27e-01  3.10e-01  3.22e-01  4.23e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  175.1745   -31.2029   0.0103    37.5276   -48.1630         1.8223261     18.707 TRIG_00995288                 
 
Foreground time interval of the image:
 -5.600  10.356 (delta_t =  15.956 [sec])
Background time interval of the image:
-239.064  -5.600 (delta_t = 233.464 [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   -5.600 sec. to   10.356 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.56945     ( -0.13685   0.135362 )
Norm@50keV  : 7.36795E-03    ( -0.00062603   0.000623114 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   57.74     using 59 bins.
 Reduced chi-squared = 1.01298
# Null hypothesis probability of 4.48e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 15.96 sec: 0.938104 ( -0.078587  0.078676 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.10419e-06 ( -1.00213e-07  1.01023e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -5.600 sec. to   10.356 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.827507     ( -0.560045   0.644813 )
Epeak [keV] : 77.5551      ( -17.0626 82.3078 )
Norm@50keV  : 1.77698E-02    ( -0.00846508   0.0196579 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   52.41     using 59 bins.
 Reduced chi-squared = 0.935893
# Null hypothesis probability of 6.11e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 15.96 sec: 0.913619 ( -0.080995  0.080934 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.05165e-06 ( -1.07913e-07  1.08813e-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: -1.39946     ( -0.393835   0.381641 )
Norm@50keV  : 1.12143E-02    ( -0.0025192   0.00251304 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   47.16     using 59 bins.
 Reduced chi-squared = 0.827368
# Null hypothesis probability of 8.21e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 1.36555 ( -0.31653  0.31757 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.08385e-07 ( -2.6382e-08  2.64399e-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: -1.20417     ( -1.72719   1.99598 )
Epeak [keV] : 236.558      ( -279.085 -279.085 )
Norm@50keV  : 1.36723E-02    ( -0.0132403   0.0703216 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   47.13     using 59 bins.
 Reduced chi-squared = 0.841607
# Null hypothesis probability of 7.95e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 1.35801 ( -0.32835  0.32216 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.93992e-08 ( -3.22825e-08  2.66947e-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 = 5.123286074816912E-01, IMY = 5.722647915154588E-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:
-239.064000 -5.600000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.4424 -40.4154    4.2   6.6   -2.7   0.8141   2.7    9.2	Vela X-1                      
170.5983 -60.5506    3.4  36.0    2.1  -1.2078  -3.4    9.4	Cen X-3                       
186.9184 -62.8983    5.8  44.1    1.8  -0.9559  -2.0   10.5	GX 301-2                      
203.4484 -43.5168    2.8  55.4  -22.6   3.9280   4.1 ------	UNKNOWN                       

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

Time interval of the image:
-5.600000 10.356000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.5042 -40.3783   11.0   6.6   -3.2  -0.0537  -1.0   10.6	Vela X-1                      
170.4909 -60.7081    3.5  36.0    2.4   0.2170   3.3    7.3	Cen X-3                       
186.6511 -62.6604    8.4  43.9    1.4   0.1245   1.4    6.6	GX 301-2                      
215.1058 -57.3700    2.1  58.3   -4.2   1.6430   5.5 ------	UNKNOWN                       
175.1746 -31.2029    0.6  37.5  -48.2   1.8223  18.7 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
338.436600 962.989800
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.5375 -40.5552    8.2  35.1 -156.9   1.0584   1.4    0.4	Vela X-1                      
170.2117 -60.5532    2.8   7.0  174.2   2.0071   4.1    5.2	Cen X-3                       
186.7231 -62.8114    2.5   4.1   83.5   2.5372   4.7    3.1	GX 301-2                      
255.8462 -37.8666   20.5  49.4   21.4   0.7998   0.6    6.8	4U 1700-377                   
256.4477 -36.4260  193.3  50.8   20.7  -0.1134  -0.1    0.6	GX 349+2                      
264.6460 -44.5704    7.1  48.8   33.8   3.4897   1.6    8.3	4U 1735-44                    
264.8878 -40.0026    2.7  52.3   30.1  11.9013   4.3 ------	UNKNOWN                       
125.2639 -74.7505    3.5  26.1  133.7   2.2443   3.3 ------	UNKNOWN                       
105.8669 -32.1642    2.9  56.8 -175.2   9.3348   4.0 ------	UNKNOWN                       
216.7143 -21.0396    3.2  44.7  -30.5   3.7630   3.6 ------	UNKNOWN                       
160.6485 -29.1894    3.1  33.7 -114.9   3.5024   3.7 ------	UNKNOWN