GRB240805B: 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: Sat Oct 19 15:01:33 EDT 2024
             Host Name: batproc1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1246989
======================================================================

  Trigger: 01246989      Segment: 000

  BAT Trigger Time: 744560968.064   [s; MET]
      Trigger Stop: 744560969.088   [s; MET]
               UTC: 2024-08-05T14:28:54.126720    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 254.239139683668   Dec: 18.3233256365182  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.47
     Image Trigger?:     NO
     Rate S/N Ratio:     10.9087121146357  [ if not an image trigger ]
     Image S/N Ratio:    7.47

  Analysis Position:   [ source = BAT ]
    RA: 254.239139683668   Dec: 18.3233256365182  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 254.223663622839   Dec: 18.3170280608998  [deg; J2000]  
        { 16h 56m 53.7s , +18d 19' 01.3" }
         +/- 1.32168020693965 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.517148134234712 [arcmin] (formal 1-sigma fit error)
    SNR: 20.4211730431763
 
  Angular difference between the analysis and refined position is 0.959070 arcmin
 
  Partial Coding Fraction: 0.859375    [ including projection effects ]

  Duration
     T90: 64.9959999322891 +/- 2.55053562398777
        Measured from: 3.01199996471405
                   to: 68.0079998970032     [s; relative to TRIGTIME]
     T50: 30.2999999523163 +/- 1.06725066691503
        Measured from: 17.8919999599457
                   to: 48.191999912262     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 15.9479999542236     
                   to: 16.9479999542236     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.75600004196167     
                   to: 96.5160000324249     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     2.495904   3.249714   2.027245   0.342407
           0.071490   0.070397   0.061248   0.055125 [error]
 Peak      0.065719   0.117323   0.096851   0.017976
           0.008199   0.008695   0.007926   0.006345 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   97.272   -0.756   96.516
T90    64.996    3.012   68.008
T50    30.300   17.892   48.192
Peak    1.000   15.948   16.948
 
 
====== 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: CPL)
 
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      -1.704    -0.056      0.056       -           -               -         5.27e-03     -1.58e-04          1.58e-04      60.860   57
CPL     -1.047    -0.250      0.266       71.969      -8.180        15.130      1.12e-02     -2.72e-03          3.87e-03      38.830   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      -1.311     -0.137     0.137       -           -               -         2.00e-02     -1.69e-03          1.68e-03      81.860   57
CPL     -0.376     -0.592     0.688       87.722     -18.864        63.370      5.88e-02     -2.85e-02          6.83e-02      74.000   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   7.94e-07  1.29e-06  1.58e-06  3.82e-06  4.75e-06  7.49e-06   erg/cm2
      90%_error_low -4.22e-08 -4.01e-08 -6.32e-08 -3.27e-07 -1.49e-07 -3.72e-07   erg/cm2
      90%_error_hi   4.30e-08  4.01e-08  6.31e-08  3.48e-07  1.49e-07  3.88e-07   erg/cm2
Peak flux       PL   6.85e-01  7.72e-01  6.22e-01  8.35e-01  2.39e+00  2.91e+00   ph/cm2/s
      90%_error_low -9.74e-02 -7.10e-02 -6.32e-02 -1.60e-01 -2.02e-01 -2.55e-01   ph/cm2/s
      90%_error_hi   1.02e-01  7.05e-02  6.28e-02  1.82e-01  2.02e-01  2.58e-01   ph/cm2/s
 
Fluence        CPL   6.98e-07  1.35e-06  1.61e-06  1.60e-06  4.47e-06  5.26e-06   erg/cm2
      90%_error_low -5.30e-08 -4.70e-08 -6.88e-08 -4.00e-07 -1.78e-07 -4.40e-07   erg/cm2
      90%_error_hi   5.40e-08  4.75e-08  6.90e-08  5.61e-07  1.79e-07  5.86e-07   erg/cm2
Peak flux      CPL   5.78e-01  8.41e-01  6.71e-01  3.32e-01  2.31e+00  2.42e+00   ph/cm2/s
      90%_error_low -1.16e-01 -8.57e-02 -7.40e-02 -1.41e-01 -2.09e-01 -2.56e-01   ph/cm2/s
      90%_error_hi   1.20e-01  8.80e-02  7.54e-02  2.46e-01  2.09e-01  3.03e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  254.2237    18.3170   0.0094    19.7996    30.8256         1.0544297     20.421 TRIG_01246989                 
 
Foreground time interval of the image:
 -0.756  11.237 (delta_t =  11.993 [sec])
Background time interval of the image:
-239.064  -0.756 (delta_t = 238.308 [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   -0.756 sec. to   96.516 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.70432     ( -0.0559771   0.0557253 )
Norm@50keV  : 5.27383E-03    ( -0.000158241   0.000157985 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   60.86     using 59 bins.
 Reduced chi-squared = 1.06772
# Null hypothesis probability of 3.39e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 97.27 sec: 0.701514 ( -0.022049  0.022113 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.74875e-06 ( -1.48527e-07  1.48913e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -0.756 sec. to   96.516 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.04726     ( -0.250003   0.26558 )
Epeak [keV] : 71.9689      ( -8.18034 15.1298 )
Norm@50keV  : 1.11601E-02    ( -0.00271523   0.00387413 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   38.83     using 59 bins.
 Reduced chi-squared = 0.693393
# Null hypothesis probability of 9.61e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 97.27 sec: 0.668007 ( -0.024887  0.025024 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.4732e-06 ( -1.78147e-07  1.78573e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   15.948 sec. to   16.948 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.31109     ( -0.137085   0.137154 )
Norm@50keV  : 1.99583E-02    ( -0.00168528   0.00168304 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   81.86     using 59 bins.
 Reduced chi-squared = 1.43614
# Null hypothesis probability of 1.71e-02 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 2.38604 ( -0.20221  0.20238 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.96716e-07 ( -1.84986e-08  1.86762e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   15.948 sec. to   16.948 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.375647     ( -0.591602   0.688033 )
Epeak [keV] : 87.7225      ( -18.8635 63.3692 )
Norm@50keV  : 5.87513E-02    ( -0.028541   0.0682619 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   74.00     using 59 bins.
 Reduced chi-squared = 1.32143
# Null hypothesis probability of 5.39e-02 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 2.30678 ( -0.20874  0.20863 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.84014e-07 ( -2.02683e-08  2.04609e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 64.996 sec.
Hardness ratio (energy fluence ratio) = 1.19541851056

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

S(15-50 keV)  = 2.0478793e-06
S(50-150 keV) = 2.4252608e-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 = 3.091552619697618E-01, IMY = -1.844809990319657E-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 -0.756000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
244.9861 -15.6445    0.5  25.7  132.7  13.3053  23.0    0.5	Sco X-1                       
254.5289  35.2018    7.7  31.3    1.2  -0.7428  -1.5    9.1	Her X-1                       
268.4380  -1.6378    5.2  33.5   78.3  -2.3253  -2.2   11.9	SW J1753.5-0127               
253.4441  -6.0404    2.7  22.4  102.3   2.5820   4.3 ------	UNKNOWN                       
244.5050  62.0008    2.3  53.7  -23.3   5.5716   5.0 ------	UNKNOWN                       

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

Time interval of the image:
-0.756000 11.236600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
245.0448 -15.5127   13.7  25.6  132.5  -0.0552  -0.8    8.5	Sco X-1                       
254.5044  35.1731    4.4  31.3    1.2   0.1439   2.6   10.4	Her X-1                       
268.3698  -1.4723    6.1  33.4   78.1  -0.1941  -1.9    1.2	SW J1753.5-0127               
254.2236  18.3170    0.6  19.8   30.8   1.0544  20.4 ------	UNKNOWN                       
193.7370 -26.7094    2.7  54.4 -159.9   0.6496   4.2 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
66.236590 962.963200
1030.936000 1121.063500
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
244.9774 -15.6523    0.6  35.2  169.6  45.7402  20.7    0.7	Sco X-1                       
254.6841  35.3857    3.6  17.1  -24.8   4.6962   3.2   11.4	Her X-1                       
263.0130 -24.8887    8.2  44.1  142.5  -8.8631  -1.4    8.6	GX 1+4                        
268.3601  -1.4536   23.5  24.2  117.5  -1.0876  -0.5    0.5	SW J1753.5-0127               
270.0489 -25.1561    0.0  46.1  134.0 -20.0580  -2.3   13.6	GX 5-1                        
270.2407 -25.6075    6.3  46.6  134.0  15.3419   1.8    8.8	GRS 1758-258                  
273.9810 -14.1640    8.5  37.9  121.8   7.8361   1.4    7.8	GX 17+2                       
288.8075  10.8923    6.3  34.2   71.7   7.8807   1.8    3.2	GRS 1915+105                  
299.6137  35.1824    1.1  43.4   31.8  36.8710  11.0    1.6	Cyg X-1                       
308.2557  41.0493   11.5  51.2   25.6   4.2909   1.0    8.8	Cyg X-3                       
285.7920   8.6771    3.2  32.1   77.3  12.8716   3.6 ------	UNKNOWN                       
267.1014  -8.0635    2.3  29.3  127.3  13.8061   5.1 ------	UNKNOWN                       
215.6310  52.7963    4.7  45.7  -57.8  18.0491   2.5 ------	UNKNOWN                       
207.8793   4.6220    3.0  47.3 -127.0  30.2011   3.8 ------	UNKNOWN