GRB240829A: 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 14:52:47 EDT 2024
             Host Name: batproc1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1251252
======================================================================

  Trigger: 01251252      Segment: 000

  BAT Trigger Time: 746596622.528   [s; MET]
      Trigger Stop: 746596623.552   [s; MET]
               UTC: 2024-08-29T03:56:28.451440    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 143.059023378014   Dec: -18.7280334116614  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    8
     Image Trigger?:     NO
     Rate S/N Ratio:     15.6843871413581  [ if not an image trigger ]
     Image S/N Ratio:    8

  Analysis Position:   [ source = BAT ]
    RA: 143.059023378014   Dec: -18.7280334116614  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 143.070597139097   Dec: -18.6953818833994  [deg; J2000]  
        { 09h 32m 16.9s , -18d 41' 43.4" }
         +/- 1.35092168384343 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.555747931763791 [arcmin] (formal 1-sigma fit error)
    SNR: 19.7926455635584
 
  Angular difference between the analysis and refined position is 2.066552 arcmin
 
  Partial Coding Fraction: 0.1523438    [ including projection effects ]

  Duration
     T90: 42.9760000705719 +/- 8.63934814855529
        Measured from: -0.407999992370605
                   to: 42.5680000782013     [s; relative to TRIGTIME]
     T50: 18.768000125885 +/- 2.06120737623349
        Measured from: 3.68799996376038
                   to: 22.4560000896454     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 0.187999963760376     
                   to: 1.18799996376038     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -1.91199994087219     
                   to: 51.8960000276566     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     1.635279   2.288953   1.617613   0.414449
           0.120416   0.127477   0.107685   0.086575 [error]
 Peak      0.097912   0.112859   0.145511   0.006566
           0.017838   0.020798   0.019729   0.012876 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   53.808   -1.912   51.896
T90    42.976   -0.408   42.568
T50    18.768    3.688   22.456
Peak    1.000    0.188    1.188
 
 
====== 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      -1.716    -0.112      0.111       -           -               -         7.43e-03     -4.95e-04          4.92e-04      52.930   57
CPL     -1.384    -0.381      0.467       91.294     -29.670       -91.294      1.10e-02     -3.85e-03          7.88e-03      51.160   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      -2.032     -0.242     0.215       -           -               -         1.70e-02     -3.46e-03          3.40e-03      88.440   57
CPL      1.012     -1.189     1.595       54.212      -7.718         8.018      5.42e-01     -5.42e-01          2.36e+00      64.820   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   6.25e-07  1.01e-06  1.23e-06  2.94e-06  3.70e-06  5.80e-06   erg/cm2
      90%_error_low -6.46e-08 -6.56e-08 -1.07e-07 -5.06e-07 -2.56e-07 -6.04e-07   erg/cm2
      90%_error_hi   6.65e-08  6.55e-08  1.07e-07  5.71e-07  2.57e-07  6.52e-07   erg/cm2
Peak flux       PL   1.17e+00  8.59e-01  4.19e-01  2.91e-01  2.58e+00  2.74e+00   ph/cm2/s
      90%_error_low -2.66e-01 -1.60e-01 -9.98e-02 -1.05e-01 -4.85e-01 -5.09e-01   ph/cm2/s
      90%_error_hi   2.75e-01  1.60e-01  9.90e-02  1.22e-01  4.85e-01  5.09e-01   ph/cm2/s
 
Fluence        CPL   5.94e-07  1.04e-06  1.25e-06  1.80e-06  3.62e-06  4.69e-06   erg/cm2
      90%_error_low -7.63e-08 -8.01e-08 -1.15e-07 -7.97e-07 -2.78e-07 -8.41e-07   erg/cm2
      90%_error_hi   7.73e-08  8.19e-08  1.16e-07  1.31e-06  2.78e-07  1.37e-06   erg/cm2
Peak flux      CPL   6.99e-01  1.26e+00  7.39e-01  9.03e-02  2.78e+00  2.79e+00   ph/cm2/s
      90%_error_low -3.00e-01 -2.26e-01 -1.85e-01 -5.52e-02 -4.93e-01 -4.97e-01   ph/cm2/s
      90%_error_hi   3.23e-01  2.31e-01  1.95e-01  7.75e-02  4.94e-01  4.97e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  143.0706   -18.6954   0.0098    39.3127   -67.3756         6.4092520     19.793 TRIG_01251252                 
 
Foreground time interval of the image:
 -1.912  51.896 (delta_t =  53.808 [sec])
Background time interval of the image:
-239.528  -1.912 (delta_t = 237.616 [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   -1.912 sec. to   51.896 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.71554     ( -0.112221   0.110703 )
Norm@50keV  : 7.43210E-03    ( -0.000495091   0.000492236 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   52.93     using 59 bins.
 Reduced chi-squared = 0.928596
# Null hypothesis probability of 6.29e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 53.81 sec: 0.992527 ( -0.065138  0.065253 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.69899e-06 ( -2.55706e-07  2.5707e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -1.912 sec. to   51.896 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.38429     ( -0.380825   0.466701 )
Epeak [keV] : 91.2945      ( -29.6696 -91.2945 )
Norm@50keV  : 1.10040E-02    ( -0.00385333   0.0078761 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   51.16     using 59 bins.
 Reduced chi-squared = 0.913571
# Null hypothesis probability of 6.58e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 53.81 sec: 0.977741 ( -0.067834  0.067849 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.6162e-06 ( -2.7823e-07  2.77949e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from    0.188 sec. to    1.188 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.03213     ( -0.240079   0.216063 )
Norm@50keV  : 1.69578E-02    ( -0.0034507   0.00340288 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   88.44     using 59 bins.
 Reduced chi-squared = 1.55158
# Null hypothesis probability of 4.80e-03 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 2.58250 ( -0.48487  0.48524 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.56664e-07 ( -3.07193e-08  3.07836e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    0.188 sec. to    1.188 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.01212     ( -1.1843   1.5998 )
Epeak [keV] : 54.2117      ( -7.74061 7.99559 )
Norm@50keV  : 0.542129    ( -0.539476   2.36617 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   64.82     using 59 bins.
 Reduced chi-squared = 1.1575
# Null hypothesis probability of 1.96e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 2.78080 ( -0.49311  0.49396 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.89845e-07 ( -3.42986e-08  3.45174e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 42.976 sec.
Hardness ratio (energy fluence ratio) = 1.21800844872

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

S(15-50 keV)  = 1.6330912e-06
S(50-150 keV) = 2.0659197e-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 = 3.150063776940881E-01, IMY = 7.558474122916268E-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:
-239.528000 -1.912000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6100  22.0284    0.9  43.9  170.9   9.6638  13.1    1.5	Crab                          
135.5661 -40.5038    3.2  36.7  -30.3   1.7832   3.6    3.5	Vela X-1                      
 95.0228  13.0290    3.4  31.9 -176.9   1.3346   3.4 ------	UNKNOWN                       
100.7742  -4.1790    2.3  14.1 -168.0   1.5751   5.0 ------	UNKNOWN                       
147.9310 -54.8855    3.0  50.7  -17.4   2.5639   3.8 ------	UNKNOWN                       
111.1710  24.4769    3.1  43.7 -152.1   2.3110   3.8 ------	UNKNOWN                       

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

Time interval of the image:
-1.912000 51.896000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.7273  22.1267    3.9  44.0  171.1  -0.5478  -3.0    8.5	Crab                          
135.4737 -40.6142    8.9  36.7  -30.0  -0.1848  -1.3    4.4	Vela X-1                      
 73.5681 -48.8392    2.0  38.0   45.2   0.9491   5.8 ------	UNKNOWN                       
 74.5782   5.7411    2.2  35.8  144.7   0.7818   5.2 ------	UNKNOWN                       
 91.6570 -13.4112    2.3  10.7  130.7   0.4380   5.0 ------	UNKNOWN                       
143.0706 -18.6954    0.6  39.3  -67.4   6.4108  19.8 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
597.972600 962.596400
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
233.5758  16.7374    3.6  29.5   69.6   2.4699   3.2 ------	UNKNOWN                       
225.5883 -45.3769    2.5  53.9  166.9   7.3603   4.6 ------	UNKNOWN                       
216.2813  44.8047    2.0  40.4   15.8   3.8020   5.6 ------	UNKNOWN                       
211.8134  51.8055    2.7  46.6    9.4   2.7880   4.3 ------	UNKNOWN                       
179.7781 -31.9262    2.1  44.8 -144.2   5.3720   5.6 ------	UNKNOWN                       
162.7003  21.0607    2.6  44.4  -61.2  10.1545   4.4 ------	UNKNOWN