GRB240825A: 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 14:54:22 EDT 2024
             Host Name: batproc1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1250617
======================================================================

  Trigger: 01250617      Segment: 000

  BAT Trigger Time: 746294013.888   [s; MET]
      Trigger Stop: 746294014.4   [s; MET]
               UTC: 2024-08-25T15:52:59.832120    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 344.551212104986   Dec: 1.03600080556074  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    9.64
     Image Trigger?:     NO
     Rate S/N Ratio:     17  [ if not an image trigger ]
     Image S/N Ratio:    9.64

  Analysis Position:   [ source = BAT ]
    RA: 344.551212104986   Dec: 1.03600080556074  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 344.570092086646   Dec: 1.01893420502123  [deg; J2000]  
        { 22h 58m 16.8s , +01d 01' 08.2" }
         +/- 0.548640743748894 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.214772630598617 [arcmin] (formal 1-sigma fit error)
    SNR: 71.7074062092812
 
  Angular difference between the analysis and refined position is 1.526889 arcmin
 
  Partial Coding Fraction: 0.5390625    [ including projection effects ]

  Duration
     T90: 416 +/- 48
        Measured from: 0.111999988555908
                   to: 416.111999988556     [s; relative to TRIGTIME]
     T50: 16 +/- 16
        Measured from: 0.111999988555908
                   to: 16.1119999885559     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 7.61199998855591     
                   to: 8.61199998855591     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: 0.111999988555908     
                   to: 832.111999988556     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     8.846667  13.391295  12.019102   3.843009
           0.179064   0.189660   0.167860   0.137380 [error]
 Peak      0.110714   0.131893   0.102026   0.006854
           0.010556   0.011598   0.010599   0.007766 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  832.000    0.112  832.112
T90   416.000    0.112  416.112
T50    16.000    0.112   16.112
Peak    1.000    7.612    8.612
 
 
====== 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: 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      -1.261    -0.036      0.036       -           -               -         3.07e-03     -5.83e-05          5.81e-05      42.510   57
CPL     -1.257    -0.036      0.037     9999.360    -9999.360      -9999.360      3.08e-03     -5.79e-05          2.05e-04      42.650   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      -1.618     -0.162     0.157       -           -               -         2.27e-02     -2.32e-03          2.29e-03      50.580   57
CPL     -1.015     -0.630     0.730       78.052     -21.571       -78.052      4.74e-02     -2.49e-02          6.57e-02      47.920   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   2.61e-06  5.55e-06  9.26e-06  3.52e-05  2.55e-05  5.26e-05   erg/cm2
      90%_error_low -1.11e-07 -1.37e-07 -1.86e-07 -1.71e-06 -4.76e-07 -1.76e-06   erg/cm2
      90%_error_hi   1.13e-07  1.37e-07  1.85e-07  1.77e-06  4.76e-07  1.81e-06   erg/cm2
Peak flux       PL   1.05e+00  9.84e-01  6.41e-01  6.46e-01  2.94e+00  3.32e+00   ph/cm2/s
      90%_error_low -1.51e-01 -9.37e-02 -8.38e-02 -1.53e-01 -2.76e-01 -3.17e-01   ph/cm2/s
      90%_error_hi   1.56e-01  9.35e-02  8.33e-02  1.77e-01  2.76e-01  3.19e-01   ph/cm2/s
 
Fluence        CPL   2.61e-06  5.54e-06  9.19e-06  3.60e-05  2.56e-05  5.25e-05   erg/cm2
      90%_error_low -1.11e-07 -1.27e-07 -1.05e-07 -4.28e-06 -5.78e-07 -3.02e-06   erg/cm2
      90%_error_hi   1.13e-07  1.48e-07  2.66e-07  -7.61e-08  3.65e-07  1.70e-06   erg/cm2
Peak flux      CPL   9.60e-01  1.05e+00  6.68e-01  3.30e-01  2.88e+00  3.01e+00   ph/cm2/s
      90%_error_low -1.79e-01 -1.17e-01 -9.31e-02 -1.66e-01 -2.83e-01 -3.38e-01   ph/cm2/s
      90%_error_hi   1.81e-01  1.21e-01  9.51e-02  3.49e-01  2.82e-01  4.16e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  344.5701     1.0189   0.0027    24.7406   101.9320        31.9669591     71.707 TRIG_01250617                 
 
Foreground time interval of the image:
  0.112  10.413 (delta_t =  10.301 [sec])
Background time interval of the image:
-50.987   0.112 (delta_t =  51.099 [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    0.112 sec. to  832.112 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.26106     ( -0.0360976   0.0362383 )
Norm@50keV  : 3.07059E-03    ( -5.82766e-05   5.81383e-05 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   42.51     using 59 bins.
 Reduced chi-squared = 0.745789
# Null hypothesis probability of 9.24e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 832 sec: 0.363834 ( -0.007782  0.007821 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.54966e-05 ( -4.75717e-07  4.76432e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    0.112 sec. to  832.112 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.2574     ( -0.0356016   0.0372815 )
Epeak [keV] : 9999.36      ( -9999.36 -9999.36 )
Norm@50keV  : 3.08427E-03    ( -5.78037e-05   0.000205532 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   42.65     using 59 bins.
 Reduced chi-squared = 0.761607
# Null hypothesis probability of 9.06e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 832 sec: 0.366778 ( -0.010857  0.004733 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.5602e-05 ( -5.77591e-07  3.64523e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from    7.612 sec. to    8.612 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.61789     ( -0.162092   0.157303 )
Norm@50keV  : 2.27496E-02    ( -0.00232276   0.00229471 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   50.58     using 59 bins.
 Reduced chi-squared = 0.887368
# Null hypothesis probability of 7.13e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 2.93997 ( -0.27555  0.27563 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.12339e-07 ( -2.31831e-08  2.34318e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    7.612 sec. to    8.612 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.01543     ( -0.6296   0.729881 )
Epeak [keV] : 78.0515      ( -21.5705 -78.0515 )
Norm@50keV  : 4.73711E-02    ( -0.0249297   0.0656865 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   47.92     using 59 bins.
 Reduced chi-squared = 0.855714
# Null hypothesis probability of 7.70e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 2.88324 ( -0.2828  0.28227 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.03395e-07 ( -2.50463e-08  2.5307e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 416.0 sec.
Hardness ratio (energy fluence ratio) = 1.66897618167

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

S(15-50 keV)  = 8.159391e-06
S(50-150 keV) = 1.7337392e-05

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 = -9.527226604463888E-02, IMY = -4.508503657237785E-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:
-50.987400 0.112000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
308.0343  40.9537    5.5  52.3 -179.0  -0.6414  -2.1    3.4	Cyg X-3                       
326.1696  38.3220   53.4  38.2 -177.2  -0.0299  -0.2    0.1	Cyg X-2                       

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

Time interval of the image:
0.112000 10.412600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
308.1066  40.9067    3.3  52.2 -179.1  -3.3631  -3.5    2.8	Cyg X-3                       
326.4046  38.3847    0.0  38.0 -177.0   0.8360   1.9   11.6	Cyg X-2                       
344.5701   1.0189    0.2  24.7  101.9  31.9717  71.7 ------	UNKNOWN                       
302.6414  31.4723    2.9  56.0  168.9   8.2787   3.9 ------	UNKNOWN                       
338.6862  15.6547    2.9  23.5  141.0   1.5511   4.0 ------	UNKNOWN                       
 35.1727  19.7372    2.9  30.4  -46.4   1.5444   4.0 ------	UNKNOWN                       
 49.1317  30.9243    3.3  43.6  -64.0   4.9963   3.5 ------	UNKNOWN                       
 45.5824  36.7366    2.1  41.8  -73.2   5.0297   5.5 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
71.412600 962.117000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
299.5482  35.2105    1.7  54.0 -175.2  27.3072   6.9    2.1	Cyg X-1                       
308.1056  40.9118   13.1  51.7 -164.5   3.0765   0.9    2.5	Cyg X-3                       
326.4414  38.3553    0.0  40.9 -151.5  -2.7598  -1.4   12.9	Cyg X-2                       
328.7661 -27.3425    3.3  32.2   77.4   7.4658   3.4 ------	UNKNOWN                       
  9.2017 -27.5913    2.5  37.1   12.6   7.0619   4.6 ------	UNKNOWN