batgrbproduct analysis for trigger=1351790

batgrbproduct Analysis for Trigger=1351790

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 22:52:39 EST 2026
             Host Name: batproc1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1351790
======================================================================

  Trigger: 01351790      Segment: 000

  BAT Trigger Time: 780394745.664   [s; MET]
      Trigger Stop: 780394762.048   [s; MET]
               UTC: 2025-09-24T08:18:29.279420    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 51.8650857219976   Dec: 74.6519011868246  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.59
     Image Trigger?:     NO
     Rate S/N Ratio:     13.9283882771841  [ if not an image trigger ]
     Image S/N Ratio:    7.59

  Flight Position:   [ source = BAT ]
    RA: 51.8650857219976   Dec: 74.6519011868246  [deg; J2000]

  Ground Position:   [ source = BAT pre-slew burst ]
    RA: 51.906870983867   Dec: 74.6643974229604  [deg; J2000]  
        { 03h 27m 37.6s , +74d 39' 51.8" }
         +/- 1.70449003570423 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.777424451435828 [arcmin] (formal 1-sigma fit error)
    SNR: 14.1993721528518
 
  Angular difference between Flight and Ground position is 1.001081 arcmin
 
  Partial Coding Fraction: 0.1230469    [ including projection effects ]

  Duration
     T90: 26.7680000066757 +/- 3.72640305790782
        Measured from: -8.22399997711182
                   to: 18.5440000295639     [s; relative to TRIGTIME]
     T50: 15.055999994278 +/- 2.99229943589583
        Measured from: -1.07200002670288
                   to: 13.9839999675751     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 15.7799999713898     
                   to: 16.7799999713898     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -9.92000007629395     
                   to: 20.0799999237061     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.730301   1.099731   1.120390   0.443873
           0.116351   0.124606   0.103420   0.081308 [error]
 Peak      0.040472   0.081364   0.078382   0.031241
           0.022341   0.024513   0.020953   0.016628 [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 3.07e-07 5.77e-07 8.39e-07 2.61e-06 2.38e-06 4.32e-06   erg/cm2
              Error 6.29e-08 7.29e-08 9.90e-08 6.67e-07 2.56e-07 7.21e-07   erg/cm2
Peak flux Power-law 6.12e-01 6.80e-01 5.41e-01 7.11e-01 2.10e+00 2.54e+00   ph/cm2/s
              Error 3.56e-01 2.50e-01 1.66e-01 4.55e-01 6.81e-01 7.34e-01   ph/cm2/s
 
Fluence   Cutoff-PL 2.70e-07 5.97e-07 8.93e-07 1.51e-06 2.35e-06 3.27e-06   erg/cm2
              Error 7.78e-08 8.12e-08 1.24e-07 1.05e-06 2.61e-07 1.08e-06   erg/cm2
Peak flux Cutoff-PL 4.92e-01 7.26e-01 5.98e-01 3.19e-01 2.02e+00 2.13e+00   ph/cm2/s
              Error 4.12e-01 2.96e-01 2.10e-01 4.05e-01 6.99e-01 8.39e-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    1.458    0.177    -      -           8.76e-03 9.32e-04   68.470 57
CPL   0.957    0.693     120.0  -38.8      1.47e-02 1.16e-02   66.930 56
 
 
=== 1-s peak spectral analysis ===
 
Model Ph_index Ph_90err Epeak  Epeak_90err Norm     Nomr_90err chi2   dof
PL    1.332    0.498    -      -           1.75e-02 5.15e-03   48.270 57
CPL   0.382    5.110      92.6  -25.9      4.87e-02 1.22e+00   47.660 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: 21.760000 sec.
T50 in the 50-300 keV band: 13.888000 sec.

 
=== Table of the duration information ==
 
        Value   tstart    tstop
T100   30.000   -9.920   20.080
T90    26.768   -8.224   18.544
T50    15.056   -1.072   13.984
Peak    1.000   15.780   16.780

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
   51.9069    74.6644   0.0135    54.7650  -165.1547         3.7336445     14.199 TRIG_01351790                 
 
Foreground time interval of the image:
 -9.920   4.776 (delta_t =  14.696 [sec])
  6.336  20.080 (delta_t =  13.744 [sec])
Background time interval of the image:
-239.664  -9.920 (delta_t = 229.744 [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 16.384000

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 16.384000

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 16.384000

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

Multiple GTIs in the spectrum
tstart tstop
-9.920000 4.776000
6.336000 20.080000
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.45772     ( -0.178222   0.175197 )
Norm@50keV  : 8.76432E-03    ( -0.000933616   0.000931001 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   68.47     using 59 bins.
 Reduced chi-squared = 1.20123
# Null hypothesis probability of 1.42e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 28.44 sec: 1.08219 ( -0.128949  0.13004 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.38215e-06 ( -2.55631e-07  2.55817e-07 ) ergs/cm2

Cutoff power-law model

Multiple GTIs in the spectrum
tstart tstop
-9.920000 4.776000
6.336000 20.080000
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 0.956537     ( -0.805562   0.580926 )
Epeak [keV] : 120.001      ( -42.4742 -120.001 )
Norm@50keV  : 1.46923E-02    ( -0.00555805   0.0175994 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   66.93     using 59 bins.
 Reduced chi-squared = 1.19518
# Null hypothesis probability of 1.51e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 28.44 sec: 1.05550 ( -0.134028  0.13496 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.35115e-06 ( -2.619e-07  2.60772e-07 ) ergs/cm2

Band function

Multiple GTIs in the spectrum
tstart tstop
-9.920000 4.776000
6.336000 20.080000
 
 
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]    : 18.6242  (-2.19234  2.58386)
R^2/D10^2   : 5.91151E-02  (-0.0221719   0.0337868)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   83.50     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 1.26e-02 with 57 degrees of freedom
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  1.154e-07   2.591e-08
25- 50  5.474e-07   9.598e-08
50-150  1.390e-06   2.388e-07
15-150  2.052e-06   2.945e-07

Thermal bremsstrahlung (OTTB)

 
 
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT [keV]    : 200.000       (-46.6012      -200)
Norm        : 4.56553       (-0.482405     0.482405)
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   68.78     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 1.36e-01 with 57 degrees of freedom
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  3.235e-07   4.656e-08
25- 50  6.222e-07   1.945e-07
50-150  1.365e-06   6.609e-07
15-150  2.310e-06   8.152e-07

Double BB

 
 
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT1 [keV]   : 6.09984        (-1.88594      3.32336)
R1^2/D10^2  : 1.63419        (-1.27714      5.91084)
kT2 [keV]   : 24.6649        (-4.3658      8.84509)
R2^2/D10^2  : 1.90751E-02    (-0.0130694   0.0119457)
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   65.86     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 1.50e-01 with 55 degrees of freedom
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  2.929e-07   1.511e-07
25- 50  5.684e-07   2.291e-07
50-150  1.494e-06   5.485e-07
15-150  2.355e-06   8.098e-07

Peak spectrum fit

Power-law model

Time interval is from   15.780 sec. to   16.780 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.33219     ( -0.520906   0.474249 )
Norm@50keV  : 1.74603E-02    ( -0.00517853   0.00511703 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   48.27     using 59 bins.
 Reduced chi-squared = 0.846842
# Null hypothesis probability of 7.88e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 2.09596 ( -0.67135  0.68997 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.71246e-07 ( -5.01193e-08  5.02827e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from   15.780 sec. to   16.780 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 0.381522     ( -3.76132   6.45796 )
Epeak [keV] : 92.6281      ( -40.8077 -92.615 )
Norm@50keV  : 4.87095E-02    ( -0.0487222   2.38673 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   47.66     using 59 bins.
 Reduced chi-squared = 0.851071
# Null hypothesis probability of 7.78e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 2.01768 ( -0.68851  0.70979 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.63976e-07 ( -5.53985e-08  5.32641e-08 ) ergs/cm2

Band function

Time interval is from   15.780 sec. to   16.780 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]    : 17.2701  (-4.72812  8.32029)
R^2/D10^2   : 0.156899  (-0.15648   0.342642)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   48.75     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 7.73e-01 with 57 degrees of freedom
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  9.488e-09   6.140e-09
25- 50  4.251e-08   2.431e-08
50-150  9.097e-08   5.865e-08
15-150  1.430e-07   8.800e-08

Thermal bremsstrahlung (OTTB)

 
 
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT [keV]    : 199.361       (-109.364      -199.363)
Norm        : 9.08328       (-2.63541     2.63567)
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   48.62     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 7.78e-01 with 57 degrees of freedom
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  2.262e-08   1.380e-08
25- 50  4.351e-08   2.644e-08
50-150  9.542e-08   5.750e-08
15-150  1.615e-07   9.715e-08

Double BB

 
 
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT1 [keV]   : 12.8744        (-11.7859      9.86313)
R1^2/D10^2  : 0.357437        (-0.353583      -0.353583)
kT2 [keV]   : 80.8899        (-87.1356      -87.1356)
R2^2/D10^2  : 9.10228E-04    (-0.000713836   0.306655)
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   46.94     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 7.72e-01 with 55 degrees of freedom
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  0.000e+00   0.000e+00
25- 50  0.000e+00   0.000e+00
50-150  0.000e+00   0.000e+00
15-150  0.000e+00   0.000e+00

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: 1.45772     ( -0.178222   0.175197 )
Norm@50keV  : 8.76432E-03    ( -0.000933616   0.000931001 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   68.47     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 1.42e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 28.44 sec: 1.08216 ( -0.128936  0.130032 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.38186e-06 ( -2.55609e-07  2.55816e-07 ) ergs/cm2

Cutoff power-law model

Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 0.956538     ( -0.805563   0.580925 )
Epeak [keV] : 120.001      ( -42.4743 -120.001 )
Norm@50keV  : 1.46923E-02    ( -0.00555805   0.0175994 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   66.93     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 1.51e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 28.44 sec: 1.05540 ( -0.133987  0.13491 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.35207e-06 ( -2.62015e-07  2.60931e-07 ) 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)  = 5.77e-07
S(50-100 keV) = 8.39e-07

T90 vs. Hardness ratio plot

T90                                   = 26.7680000066757 sec.
Hardness ratio (energy fluence ratio) = 1.45407

Color vs. Color plot

Count Ratio  (25-50 keV) / (15-25 keV) = 1.50586
Count Ratio (50-100 keV) / (15-25 keV) = 1.53415

Mask shadow pattern

IMX = -1.368494646823022E+00, IMY = 3.627303073479849E-01

TIME vs. PHA plot around the trigger time

Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 16.384000

TIME vs. DetID plot around the trigger time

Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 16.384000

100 us light curve (15-350 keV)

Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 16.384000

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:
-239.664000 -9.920000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6177  22.0106    0.5  20.8  -81.2   9.3093  22.2    0.9	Crab                          
103.1884  65.9312    2.7  53.2 -142.2   7.4510   4.2 ------	UNKNOWN                       
105.3052   9.1428    3.0  43.8  -64.2   6.2265   3.9 ------	UNKNOWN

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

Time interval of the image:
-9.920000 4.776000
6.336000 20.080000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.7804  21.8968    8.4  21.0  -80.9  -0.1165  -1.4   10.8	Crab                          
 37.1698 -13.2572    2.2  41.0   55.3   0.9364   5.2 ------	UNKNOWN                       
 70.8934 -26.5184    1.9  47.6    6.3   0.8133   6.1 ------	UNKNOWN                       
 71.0991 -22.6138    2.6  43.8    4.9   0.4845   4.4 ------	UNKNOWN                       
 47.5486  41.6037    2.9  24.5  172.3   0.2699   4.0 ------	UNKNOWN                       
 51.9058  74.6643    0.8  54.8 -165.2   3.7600  14.3 ------	UNKNOWN

Post-slew image of 15-350 keV band

Time interval of the image:
171.436600 962.474100
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6044  22.0140    1.0  55.2    2.2  28.4671  11.0    1.6	Crab                          
 74.8765  66.6254    3.0  10.9  -16.2   3.8935   3.9 ------	UNKNOWN                       
280.8524  86.4792    2.6  17.9 -150.1   3.9296   4.4 ------	UNKNOWN                       
106.7500  35.2805    2.2  47.1  -27.2  10.0640   5.2 ------	UNKNOWN                       
242.5901  48.0502    3.6  57.1 -149.9  21.6618   3.2 ------	UNKNOWN

Plot creation:
Sun Mar  1 23:23:10 EST 2026