batgrbproduct analysis for trigger=1401726

batgrbproduct Analysis for Trigger=1401726

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 (local time): Sat Feb 28 21:34:17 EST 2026
             Host Name: batproc1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1401726
======================================================================

  Trigger: 01401726      Segment: 000

  BAT Trigger Time: 781373250.368   [s; MET]
      Trigger Stop: 781373251.776   [s; MET]
               UTC: 2025-10-05T16:06:53.917040    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 75.6734431496227   Dec: 16.8817079854514  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    13.73
     Image Trigger?:     NO
     Rate S/N Ratio:     35.7770876399966  [ if not an image trigger ]
     Image S/N Ratio:    13.73

  Flight Position:   [ source = BAT ]
    RA: 75.6734431496227   Dec: 16.8817079854514  [deg; J2000]

  Ground Position:   [ source = BAT pre-slew burst ]
    RA: 75.668070906342   Dec: 16.8850317932806  [deg; J2000]  
        { 05h 02m 40.3s , +16d 53' 06.1" }
         +/- 1.43476106283473 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.562112185317926 [arcmin] (formal 1-sigma fit error)
    SNR: 18.1613257594782
 
  Angular difference between Flight and Ground position is 0.367298 arcmin
 
  Partial Coding Fraction: 0.765625    [ including projection effects ]

  Duration
     T90: 1.51999998092651 +/- 0.196010160416378
        Measured from: -0.0440000295639038
                   to: 1.47599995136261     [s; relative to TRIGTIME]
     T50: 0.843999981880188 +/- 0.278567765201334
        Measured from: 0.335999965667725
                   to: 1.17999994754791     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 0.583999991416931     
                   to: 1.58399999141693     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.200000047683716     
                   to: 1.58799993991852     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.051989   0.113695   0.129004   0.063932
           0.009925   0.011168   0.010480   0.008456 [error]
 Peak      0.031967   0.074174   0.094648   0.048125
           0.007496   0.008526   0.008254   0.006751 [error]

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

======================================================================
 
=== 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   Power-law 1.73e-08 4.56e-08 9.67e-08 5.31e-07 2.61e-07 6.90e-07   erg/cm2
              Error 3.60e-09 5.62e-09 9.57e-09 1.26e-07 2.57e-08 1.29e-07   erg/cm2
Peak flux Power-law 3.42e-01 5.21e-01 5.94e-01 1.29e+00 1.84e+00 2.75e+00   ph/cm2/s
              Error 8.52e-02 7.80e-02 6.24e-02 3.13e-01 2.00e-01 3.25e-01   ph/cm2/s
 
Fluence   Cutoff-PL 1.72e-08 4.58e-08 9.73e-08 5.22e-07 2.61e-07 6.81e-07   erg/cm2
              Error 3.75e-09 5.45e-09 9.54e-09 1.89e-07 2.60e-08 1.85e-07   erg/cm2
Peak flux Cutoff-PL 3.41e-01 5.21e-01 5.94e-01 1.28e+00 1.84e+00 2.91e+00   ph/cm2/s
              Error 8.52e-02 7.81e-02 6.26e-02 2.33e-01 2.00e-01 4.49e-01   ph/cm2/s
 
Fluence        Band -------- -------- -------- -------- -------- --------   erg/cm2
              Error -------- -------- -------- -------- -------- --------   erg/cm2
Peak flux      Band -------- -------- -------- -------- -------- --------   ph/cm2/s
              Error -------- -------- -------- -------- -------- --------   ph/cm2/s

 
=== Time-averaged spectral analysis ===
 
Model Ph_index Ph_90err Epeak  Epeak_90err Norm     Nomr_90err chi2   dof
PL    0.913    0.170    -      -           1.31e-02 1.27e-03   53.600 57
CPL   0.906    0.289    10000.0    0.0      1.32e-02 1.21e-03   53.600 56
 
 
=== 1-s peak spectral analysis ===
 
Model Ph_index Ph_90err Epeak  Epeak_90err Norm     Nomr_90err chi2   dof
PL    0.811    0.196    -      -           1.60e-02 1.78e-03   48.460 57
CPL   0.809    0.198    9999.4    0.0      1.61e-02 6.31e-03   48.480 56
 
Model      : spectral model: simple power-law (PL) and cutoff power-law (CPL)
Ph_index   : photon index: E^-{Ph_index} (minus sign is not included in the 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 PL model and at 1 keV in CPL model
Nomr_90err : 90% error of the normalization
chi2       : Chi-Squared
dof        : degree of freedom

 
=== T90/T50 calculation in the 50-300 keV band (BATSE band) using 64 ms lc ===
 
T90 in the 50-300 keV band: 1.472000 sec.
T50 in the 50-300 keV band: 0.768000 sec.

 
=== Table of the duration information ==
 
        Value   tstart    tstop
T100    1.788   -0.200    1.588
T90     1.520   -0.044    1.476
T50     0.844    0.336    1.180
Peak    1.000    0.584    1.584

Click here for the BAT GCN circular template

Estimated redshift from machine learning (Ukwatta et al. 2016) - may take a few minute to calcaulte

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
   75.6681    16.8850   0.0106    31.4409    -3.8761         0.3752191     18.161 TRIG_01401726                 
 
Foreground time interval of the image:
 -0.200   1.588 (delta_t =   1.788 [sec])
Background time interval of the image:
-141.867  -0.200 (delta_t = 141.667 [sec])

Lightcurves

Notes:

1) The mask-weighted light curves are using the flight position.
2) Multiple plots of different time binning/intervals are shown to cover all scenarios of short/long GRBs, rate/image triggers, and real/false positives.
3) For all the mask-weighted lightcurves, the y-axis units are counts/sec/det where a det is 0.4 x 0.4 = 0.16 sq cm.
4) The verticle lines correspond to following: green dotted lines are T50 interval, black dotted lines are T90 interval, blue solid line(s) is a spacecraft slew start time, and orange solid line(s) is a spacecraft slew end time.
5) Time of each bin is in the middle of the bin.

1 s binning

From T0-310 s to T0+310 s

From T100_start - 20 s to T100_end + 30 s

Full time interval

64 ms binning

Full time interval

From T100_start to T100_end

From T0-5 sec to T0+5 sec

16 ms binning

From T100_start-5 s to T100_start+5 s

Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 1.408000

8 ms binning

From T100_start-3 s to T100_start+3 s

Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 1.408000

2 ms binning

From T100_start-1 s to T100_start+1 s

Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 1.408000

SN=5 or 10 sec. binning (whichever binning is satisfied first)

SN=5 or 10 sec. binning (T < 200 sec)

Quad-rate summed light curves (from T0-300s to T0+1000s)

Spectral Evolution

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   -0.200 sec. to    1.588 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 0.912837     ( -0.173427   0.167294 )
Norm@50keV  : 1.30656E-02    ( -0.00127567   0.00126272 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   53.60     using 59 bins.
 Reduced chi-squared = 0.940351
# Null hypothesis probability of 6.03e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 1.788 sec: 1.49985 ( -0.14649  0.14716 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.60909e-07 ( -2.5611e-08  2.57254e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from   -0.200 sec. to    1.588 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 0.906175     ( -0.380821   0.197565 )
Epeak [keV] : 10000.00      ( -10000 -10000 )
Norm@50keV  : 1.31508E-02    ( -0.00121312   0.0012127 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   53.60     using 59 bins.
 Reduced chi-squared = 0.957143
# Null hypothesis probability of 5.66e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 1.788 sec: 1.49782 ( -0.14515  0.14271 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.6068e-07 ( -2.66142e-08  2.54531e-08 ) ergs/cm2

Band function

Time interval is from   -0.200 sec. to    1.588 sec.
 
 
Spectral model in the Band function:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
alpha       :    (     )
beta        :     (     )
Epeak [keV] :       (   )
Norm@50keV   :     (     )
------------------------------------------------------------
 
Photon flux (15-150 keV)    in  sec:  (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2

Single BB

 
Spectral model blackbody:
------------------------------------------------------------
Parameters  : value    Lower 90%  Upper 90%
kT [keV]    : 24.7677  (-3.19937  3.98085)
R^2/D10^2   : 3.77249E-02  (-0.0136866   0.0202284)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   72.65     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 7.92e-02 with 57 degrees of freedom
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  7.224e-09   1.418e-09
25- 50  4.079e-08   6.660e-09
50-150  1.858e-07   2.818e-08
15-150  2.338e-07   3.147e-08

Thermal bremsstrahlung (OTTB)

 
 
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT [keV]    : 200.000       (-15.7842      -200)
Norm        : 6.16674       (-0.608615     0.608615)
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   94.12     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 1.44e-03 with 57 degrees of freedom
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  2.744e-08   1.472e-08
25- 50  5.279e-08   2.870e-08
50-150  1.158e-07   6.297e-08
15-150  1.960e-07   1.032e-07

Double BB

 
 
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT1 [keV]   : 10.2625        (-4.32184      5.24322)
R1^2/D10^2  : 0.317132        (-0.203206      0.71284)
kT2 [keV]   : 44.7792        (-15.292      -45.2057)
R2^2/D10^2  : 5.56140E-03    (-0.00488902   0.0139406)
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   54.63     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 4.89e-01 with 55 degrees of freedom
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  1.463e-08   7.753e-09
25- 50  4.828e-08   2.554e-08
50-150  1.994e-07   1.034e-07
15-150  2.623e-07   1.310e-07

Peak spectrum fit

Power-law model

Time interval is from    0.584 sec. to    1.584 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 0.810554     ( -0.200437   0.191221 )
Norm@50keV  : 1.60291E-02    ( -0.00179891   0.00176591 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   48.46     using 59 bins.
 Reduced chi-squared = 0.850175
# Null hypothesis probability of 7.82e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 1.84159 ( -0.19997  0.20071 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.86505e-07 ( -2.0248e-08  2.02995e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from    0.584 sec. to    1.584 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 0.809207     ( -0.207506   0.187887 )
Epeak [keV] : 9999.36      ( -9999.36 -9999.36 )
Norm@50keV  : 1.61451E-02    ( -0.00169424   0.0109243 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   48.48     using 59 bins.
 Reduced chi-squared = 0.865714
# Null hypothesis probability of 7.52e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 1.84109 ( -0.19998  0.20063 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.8678e-07 ( -2.28381e-08  2.22747e-08 ) ergs/cm2

Band function

Time interval is from    0.584 sec. to    1.584 sec.
 
 
Spectral model in the Band function:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
alpha       :    (     )
beta        :     (     )
Epeak [keV] :       (   )
Norm@50keV   :     (     )
------------------------------------------------------------
 
Photon flux (15-150 keV)    in  sec:  (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2

Single BB

 
Spectral model blackbody:
------------------------------------------------------------
Parameters  : value    Lower 90%  Upper 90%
kT [keV]    : 27.6398  (-4.16792  5.47617)
R^2/D10^2   : 3.42166E-02  (-0.013897   0.0215631)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   65.71     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 2.01e-01 with 57 degrees of freedom
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  4.295e-09   9.825e-10
25- 50  2.557e-08   4.685e-09
50-150  1.418e-07   2.400e-08
15-150  1.717e-07   2.535e-08

Thermal bremsstrahlung (OTTB)

 
 
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT [keV]    : 200.000       (-17.7904      -200)
Norm        : 7.46649       (-0.832592     0.832592)
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   90.49     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 3.14e-03 with 57 degrees of freedom
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  1.860e-08   1.031e-08
25- 50  3.577e-08   1.965e-08
50-150  7.846e-08   4.257e-08
15-150  1.328e-07   7.270e-08

Double BB

 
 
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT1 [keV]   : 10.1815        (-4.75691      5.77743)
R1^2/D10^2  : 0.387777        (-0.272389      2.50622)
kT2 [keV]   : 51.5304        (-19.0748      -51.538)
R2^2/D10^2  : 5.27056E-03    (-0.00400639   0.014546)
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   49.36     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 6.89e-01 with 55 degrees of freedom
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  9.727e-09   5.495e-09
25- 50  3.186e-08   1.676e-08
50-150  1.481e-07   7.901e-08
15-150  1.897e-07   9.535e-08

Pre-slew spectrum (Pre-slew PHA with pre-slew DRM)

Power-law model

 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 0.912837     ( -0.173427   0.167294 )
Norm@50keV  : 1.30656E-02    ( -0.00127567   0.00126272 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   53.60     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 6.03e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 1.788 sec: 1.49986 ( -0.146497  0.147155 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.60882e-07 ( -2.56551e-08  2.57606e-08 ) ergs/cm2

Cutoff power-law model

Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 0.905619     ( -0.174554   0.169194 )
Epeak [keV] : 9998.27      ( -9998.12 -9998.12 )
Norm@50keV  : 1.31517E-02    ( -0.00121232   0.0128521 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   53.60     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 5.66e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 1.788 sec: 1.49553 ( -0.14978  0.15067 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.6054e-07 ( -2.61441e-08  2.61137e-08 ) ergs/cm2

Band function

 
 
Spectral model in the Band function:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
alpha       :    (     )
beta        :     (     )
Epeak [keV] :       (   )
Norm@50keV   :     (     )
------------------------------------------------------------
 
Photon flux (15-150 keV)    in  sec:  (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2

S(25-50 keV) vs. S(50-100 keV) plot

S(25-50 keV)  = 4.56e-08
S(50-100 keV) = 9.67e-08

T90 vs. Hardness ratio plot

T90                                   = 1.51999998092651 sec.
Hardness ratio (energy fluence ratio) = 2.12061

Color vs. Color plot

Count Ratio  (25-50 keV) / (15-25 keV) = 2.1869
Count Ratio (50-100 keV) / (15-25 keV) = 2.48137

Mask shadow pattern

IMX = 6.099852948830339E-01, IMY = 4.132883317836925E-02

TIME vs. PHA plot around the trigger time

Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 1.408000

TIME vs. DetID plot around the trigger time

Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 1.408000

100 us light curve (15-350 keV)

Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 1.408000

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:
-141.867370 -0.200000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6201  22.0037    0.5  32.3  -21.1   5.8857  23.6    1.0	Crab                          
 58.7859   8.5240    3.5  33.5   30.7   1.0356   3.3 ------	UNKNOWN                       
347.1017  48.2033    3.9  45.7  162.8   1.5338   2.9 ------	UNKNOWN                       
  8.1163  68.9174    2.3  35.9 -164.7   1.2706   4.9 ------	UNKNOWN

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

Time interval of the image:
-0.200000 1.588000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.5530  22.0543    3.8  32.2  -21.0  -0.0597  -3.0    5.1	Crab                          
 75.6681  16.8850    0.6  31.4   -3.9   0.3752  18.2 ------	UNKNOWN                       
346.8401  69.8093    2.0  43.3 -166.4   0.1540   5.6 ------	UNKNOWN

Post-slew image of 15-350 keV band

Time interval of the image:
100.532590 962.766800
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6257  22.0151    0.4   9.1 -122.8  35.6772  30.4    0.4	Crab                          
 58.8108   4.6967    3.3  20.5   58.5   4.3145   3.5 ------	UNKNOWN                       
 66.7570 -36.4875    2.5  54.0   11.8  14.3997   4.7 ------	UNKNOWN                       
 67.8702 -32.5909    3.0  50.0   11.5   9.0212   3.9 ------	UNKNOWN                       
 75.6908  48.6733    3.2  31.8 -177.0   4.7077   3.6 ------	UNKNOWN                       
 80.9801 -39.7684    2.8  56.9   -1.9  15.2024   4.2 ------	UNKNOWN                       
119.7202  23.4468    2.7  41.7 -103.6  21.6654   4.2 ------	UNKNOWN

Plot creation:
Sun Mar  1 23:20:14 EST 2026