GRB230816A: 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 Sep 29 23:28:04 EDT 2023
             Host Name: batproc1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1185673
======================================================================

  Trigger: 01185673      Segment: 000

  BAT Trigger Time: 713894960.128   [s; MET]
      Trigger Stop: 713894961.152   [s; MET]
               UTC: 2023-08-16T16:08:48.290780    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 328.37496109811   Dec: 37.828503929981  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.42
     Image Trigger?:     NO
     Rate S/N Ratio:     15.0332963783729  [ if not an image trigger ]
     Image S/N Ratio:    7.42

  Analysis Position:   [ source = BAT ]
    RA: 328.37496109811   Dec: 37.828503929981  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 328.453175208218   Dec: 37.8577755359379  [deg; J2000]  
        { 21h 53m 48.8s , +37d 51' 28.0" }
         +/- 1.20623606222768 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.379462930520351 [arcmin] (formal 1-sigma fit error)
    SNR: 23.2694710435944
 
  Angular difference between the analysis and refined position is 4.101017 arcmin
 
  Partial Coding Fraction: 0.984375    [ including projection effects ]

  Duration
     T90: 19.4479999542236 +/- 3.21816099943384
        Measured from: -4.24800002574921
                   to: 15.1999999284744     [s; relative to TRIGTIME]
     T50: 7.25599992275238 +/- 1.54746240251562
        Measured from: -0.723999977111816
                   to: 6.53199994564056     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 0.595999956130981     
                   to: 1.59599995613098     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -5.56400001049042     
                   to: 16.4839999675751     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.359209   0.433432   0.346847   0.106696
           0.028446   0.029565   0.025859   0.022254 [error]
 Peak      0.038055   0.046159   0.038396   0.012128
           0.006296   0.006567   0.005782   0.004864 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   22.048   -5.564   16.484
T90    19.448   -4.248   15.200
T50     7.256   -0.724    6.532
Peak    1.000    0.596    1.596
 
 
====== 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      -1.426    -0.132      0.132       -           -               -         3.50e-03     -2.56e-04          2.55e-04      67.400   57
CPL     -1.398    -0.159      0.369      998.553    -998.553      -998.553      3.63e-03     -3.70e-04          1.38e-04      67.510   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      -1.463     -0.268     0.263       -           -               -         8.05e-03     -1.24e-03          1.22e-03      43.950   57
CPL     -1.456     -0.274     0.315     9999.320    -9999.320      -9999.320      8.08e-03     -1.25e-03          1.28e-02      43.960   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   9.21e-08  1.77e-07  2.64e-07  8.45e-07  7.43e-07  1.38e-06   erg/cm2
      90%_error_low -1.16e-08 -1.35e-08 -2.53e-08 -1.65e-07 -6.07e-08 -1.86e-07   erg/cm2
      90%_error_hi   1.20e-08  1.34e-08  2.52e-08  1.92e-07  6.13e-08  2.08e-07   erg/cm2
Peak flux       PL   3.20e-01  3.29e-01  2.39e-01  2.78e-01  9.95e-01  1.16e+00   ph/cm2/s
      90%_error_low -7.78e-02 -5.10e-02 -4.73e-02 -9.86e-02 -1.46e-01 -1.76e-01   ph/cm2/s
      90%_error_hi   8.27e-02  5.03e-02  4.65e-02  1.28e-01  1.46e-01  1.79e-01   ph/cm2/s
 
Fluence        CPL   9.25e-08  1.75e-07  2.62e-07  8.72e-07  7.49e-07  1.37e-06   erg/cm2
      90%_error_low -1.34e-08 -1.57e-08 -2.40e-08 -4.26e-07 -7.30e-08 -3.90e-07   erg/cm2
      90%_error_hi   1.23e-08  1.89e-08  2.66e-08  7.21e-08  5.82e-08  1.01e-07   erg/cm2
Peak flux      CPL   3.24e-01  3.29e-01  2.38e-01  2.93e-01  9.98e-01  1.17e+00   ph/cm2/s
      90%_error_low -8.35e-02 -5.07e-02 -4.61e-02 -5.17e-02 -1.58e-01 -1.74e-01   ph/cm2/s
      90%_error_hi   7.89e-02  5.55e-02  4.88e-02  1.11e-01  1.50e-01  1.65e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  328.4532    37.8578   0.0083    12.6449   142.6552         1.3068170     23.269 TRIG_01185673                 
 
Foreground time interval of the image:
 -5.564  16.484 (delta_t =  22.048 [sec])
Background time interval of the image:
-239.128  -5.564 (delta_t = 233.564 [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   -5.564 sec. to   16.484 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.42592     ( -0.131674   0.131524 )
Norm@50keV  : 3.50490E-03    ( -0.000255731   0.000254788 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   67.40     using 59 bins.
 Reduced chi-squared = 1.18246
# Null hypothesis probability of 1.63e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 22.05 sec: 0.429419 ( -0.031206  0.031252 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.42999e-07 ( -6.07096e-08  6.13204e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -5.564 sec. to   16.484 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.42313     ( -0.159294   0.368952 )
Epeak [keV] : 1.00000E+04      ( -10000 -10000 )
Norm@50keV  : 3.51679E-03    ( -0.000257269   0.000249923 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   67.41     using 59 bins.
 Reduced chi-squared = 1.20375
# Null hypothesis probability of 1.41e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 22.05 sec: 0.431268 ( -0.041085  0.03719 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.49252e-07 ( -7.30003e-08  5.82032e-08 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from    0.596 sec. to    1.596 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.46257     ( -0.268483   0.26299 )
Norm@50keV  : 8.04819E-03    ( -0.00123911   0.00122079 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   43.95     using 59 bins.
 Reduced chi-squared = 0.771053
# Null hypothesis probability of 8.97e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 0.994980 ( -0.146071  0.14619 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.68493e-08 ( -1.31433e-08  1.33618e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    0.596 sec. to    1.596 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.45565     ( -0.271495   0.317304 )
Epeak [keV] : 9999.32      ( -9999.36 -9999.36 )
Norm@50keV  : 8.07697E-03    ( -0.0012493   0.0127897 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   43.96     using 59 bins.
 Reduced chi-squared = 0.785
# Null hypothesis probability of 8.78e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 0.997995 ( -0.157694  0.150125 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.77141e-08 ( -1.43767e-08  1.23559e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 19.448 sec.
Hardness ratio (energy fluence ratio) = 1.48874383186

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

S(15-50 keV)  = 2.6908435e-07
S(50-150 keV) = 4.739269e-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 = -1.783571186160879E-01, IMY = -1.360920252802561E-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:
-239.128000 -5.564000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
299.5865  35.1904    0.6  35.4  155.7  10.9299  18.1    0.7	Cyg X-1                       
308.1893  41.0349    4.3  27.3  162.7   1.1804   2.7    6.1	Cyg X-3                       
326.1432  38.1874    9.4  14.3  146.2   0.4250   1.2    8.2	Cyg X-2                       
354.0541  -5.4229    2.4  46.8   46.4   4.8529   4.9  482.5	UNKNOWN                       
269.5498  83.3047    3.3  48.1 -129.1   5.6146   3.5 ------	UNKNOWN                       

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

Time interval of the image:
-5.564000 16.484000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
299.7642  35.3106    6.0  35.2  155.8  -0.1664  -1.9   10.7	Cyg X-1                       
308.0499  40.8845    7.9  27.4  162.4   0.0982   1.4    4.9	Cyg X-3                       
326.1548  38.4822    8.2  14.2  147.3   0.0847   1.4    9.7	Cyg X-2                       
340.4687  16.6829    2.1  24.1   68.9   0.4173   5.5 ------	UNKNOWN                       
328.4532  37.8578    0.5  12.6  142.7   1.3069  23.2 ------	UNKNOWN                       
283.8020  46.7014    2.0  43.2  178.8   0.5568   5.8 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
71.972600 962.961900
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.4360  35.4145    4.6  57.8 -160.7 -14.0469  -2.5    4.4	Her X-1                       
288.6996  10.8177   66.3  44.6  150.4  -0.6476  -0.2    9.6	GRS 1915+105                  
299.5919  35.1894    0.4  23.2  179.4  37.3832  27.6    0.7	Cyg X-1                       
308.1528  40.9858    3.9  15.9 -165.2   3.8512   3.0    2.8	Cyg X-3                       
326.1581  38.1720    7.5   1.8 -171.5   1.8080   1.5    9.0	Cyg X-2                       
  7.8716   4.8086    1.8  48.8   29.7  16.4865   6.5  553.0	UNKNOWN                       
258.3148  62.1128    3.3  48.1 -129.2  19.3366   3.5 ------	UNKNOWN