GRB240905E: 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 14:46:37 EDT 2024
             Host Name: batproc1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1252695
======================================================================

  Trigger: 01252695      Segment: 000

  BAT Trigger Time: 747253597.76   [s; MET]
      Trigger Stop: 747253598.784   [s; MET]
               UTC: 2024-09-05T18:26:03.638540    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 345.799313401164   Dec: 35.4951714706035  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    6.52
     Image Trigger?:     NO
     Rate S/N Ratio:     29.3768616431368  [ if not an image trigger ]
     Image S/N Ratio:    6.52

  Analysis Position:   [ source = BAT ]
    RA: 345.799313401164   Dec: 35.4951714706035  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 345.794666258013   Dec: 35.512764499858  [deg; J2000]  
        { 23h 03m 10.7s , +35d 30' 46.0" }
         +/- 1.87786597868521 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.749441800547443 [arcmin] (formal 1-sigma fit error)
    SNR: 12.3642836626612
 
  Angular difference between the analysis and refined position is 1.079711 arcmin
 
  Partial Coding Fraction: 0.2226562    [ including projection effects ]

  Duration
     T90: 121.155999898911 +/- 31.3357303537861
        Measured from: 0.340000033378601
                   to: 121.495999932289     [s; relative to TRIGTIME]
     T50: 51.0599999427795 +/- 10.9917381379608
        Measured from: 6.22800004482269
                   to: 57.2879999876022     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 0.0839999914169312     
                   to: 1.08399999141693     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: 0.0839999914169312     
                   to: 139.388000011444     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.542498   1.031036   0.891685   0.343594
           0.097369   0.101910   0.087673   0.075636 [error]
 Peak      0.072641   0.086225   0.118070   0.066608
           0.014135   0.016638   0.016036   0.013921 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  139.304    0.084  139.388
T90   121.156    0.340  121.496
T50    51.060    6.228   57.288
Peak    1.000    0.084    1.084
 
 
====== 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      -1.167    -0.181      0.186       -           -               -         1.38e-03     -1.42e-04          1.42e-04      60.410   57
CPL     -1.011    -0.466      0.765      352.231    -352.231      -352.231      1.63e-03     -3.76e-04          1.93e-03      60.250   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      -1.009     -0.273     0.287       -           -               -         2.18e-02     -3.42e-03          3.39e-03      60.280   57
CPL     -0.949     -0.332     0.815      987.934    -987.934      -987.934      2.33e-02     -4.74e-03          2.02e-03      60.360   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   1.80e-07  4.05e-07  7.22e-07  3.03e-06  1.97e-06  4.33e-06   erg/cm2
      90%_error_low -3.63e-08 -5.06e-08 -8.49e-08 -7.38e-07 -2.16e-07 -7.93e-07   erg/cm2
      90%_error_hi   3.88e-08  4.97e-08  8.40e-08  8.99e-07  2.18e-07  9.28e-07   erg/cm2
Peak flux       PL   5.62e-01  7.58e-01  7.54e-01  1.35e+00  2.51e+00  3.43e+00   ph/cm2/s
      90%_error_low -1.76e-01 -1.55e-01 -1.24e-01 -4.35e-01 -4.02e-01 -5.55e-01   ph/cm2/s
      90%_error_hi   1.97e-01  1.50e-01  1.22e-01  5.54e-01  4.03e-01  5.78e-01   ph/cm2/s
 
Fluence        CPL   1.73e-07  4.10e-07  7.33e-07  2.43e-06  1.95e-06  3.74e-06   erg/cm2
      90%_error_low -4.47e-08 -4.92e-08 -9.36e-08 -1.44e-06 -2.32e-07 -1.44e-06   erg/cm2
      90%_error_hi   3.98e-08  5.61e-08  9.93e-08  7.91e-07  2.27e-07  1.43e-06   erg/cm2
Peak flux      CPL   5.61e-01  7.57e-01  7.52e-01  1.42e+00  2.52e+00  3.48e+00   ph/cm2/s
      90%_error_low -1.76e-01 -1.61e-01 -1.22e-01 -7.94e-01 -4.34e-01 -9.55e-01   ph/cm2/s
      90%_error_hi   1.97e-01  1.60e-01  1.43e-01  1.98e-01  4.18e-01  4.89e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  345.7947    35.5128   0.0156    37.6757   128.7829         1.3053611     12.364 TRIG_01252695                 
 
Foreground time interval of the image:
  0.084  16.141 (delta_t =  16.057 [sec])
Background time interval of the image:
-239.760   0.084 (delta_t = 239.844 [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    0.084 sec. to  139.388 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.1669     ( -0.181414   0.18626 )
Norm@50keV  : 1.37888E-03    ( -0.000142405   0.000141916 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   60.41     using 59 bins.
 Reduced chi-squared = 1.05982
# Null hypothesis probability of 3.54e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 139.3 sec: 0.161139 ( -0.017405  0.017499 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.96763e-06 ( -2.16446e-07  2.17573e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    0.084 sec. to  139.388 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.01073     ( -0.466022   0.765224 )
Epeak [keV] : 352.231      ( -352.233 -352.233 )
Norm@50keV  : 1.62762E-03    ( -0.000376238   0.00192904 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   60.25     using 59 bins.
 Reduced chi-squared = 1.07589
# Null hypothesis probability of 3.25e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 139.3 sec: 0.159992 ( -0.018112  0.017983 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.95034e-06 ( -2.32189e-07  2.27126e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from    0.084 sec. to    1.084 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.0087     ( -0.273204   0.2867 )
Norm@50keV  : 2.18169E-02    ( -0.00342368   0.0033884 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   60.28     using 59 bins.
 Reduced chi-squared = 1.05754
# Null hypothesis probability of 3.58e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 2.51295 ( -0.40169  0.40307 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.35218e-07 ( -3.84339e-08  3.85735e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    0.084 sec. to    1.084 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.00269     ( -0.332391   0.814806 )
Epeak [keV] : 1.00000E+04      ( -10000 -10000 )
Norm@50keV  : 2.19463E-02    ( -0.00342985   0.00333125 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   60.28     using 59 bins.
 Reduced chi-squared = 1.07643
# Null hypothesis probability of 3.24e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 2.52134 ( -0.4336  0.41797 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.35586e-07 ( -4.10321e-08  4.03892e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 121.156 sec.
Hardness ratio (energy fluence ratio) = 1.78155835898

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

S(15-50 keV)  = 5.847846e-07
S(50-150 keV) = 1.3828452e-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 = -4.836911996927961E-01, IMY = -6.019577487709601E-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:
-239.760000 0.084000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6217  22.0176    0.9  48.0  -27.0   9.2218  12.8    0.7	Crab                          
325.9880  38.3294   10.1  48.2  146.8   1.5125   1.1    8.7	Cyg X-2                       
 36.9170  13.4040    2.7  38.1   40.1   2.7210   4.2 ------	UNKNOWN                       
338.4672  82.5910    2.8  34.9 -146.3   1.8156   4.1 ------	UNKNOWN                       
 94.0267  76.9046    2.5  33.7 -114.8   2.4226   4.6 ------	UNKNOWN                       
 93.6402  55.8627    2.5  34.5  -76.8   2.9402   4.6 ------	UNKNOWN                       

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

Time interval of the image:
0.084000 16.140600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.5806  22.1470   37.8  47.9  -27.0   0.0329   0.3    8.5	Crab                          
326.1480  38.4190    6.4  48.0  146.7   0.3447   1.8    5.9	Cyg X-2                       
345.7947  35.5128    0.9  37.7  128.8   1.3055  12.4 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
93.940600 322.940600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
299.5832  35.1921    1.3  37.4 -167.6   3.8108   8.8    0.7	Cyg X-1                       
308.2075  40.8954    3.2  29.8 -159.2   1.2471   3.6    5.6	Cyg X-3                       
326.3700  38.2988   28.3  15.8 -165.0   0.1231   0.4    9.4	Cyg X-2                       
346.9789  -2.7146    2.6  38.2   87.1   4.2300   4.4 ------	UNKNOWN                       
306.1649   1.6005    2.8  50.0  145.3   5.9966   4.2 ------	UNKNOWN                       
 40.3701  14.6508    2.2  52.9    7.6   3.5865   5.2 ------	UNKNOWN                       
343.3150  35.3971    2.0   2.0  177.0   1.6641   5.8 ------	UNKNOWN                       
 41.4775  33.4591    3.3  45.3  -15.4   1.7786   3.5 ------	UNKNOWN                       
301.3309  47.8837    2.5  34.9 -146.3   1.9656   4.7 ------	UNKNOWN