batgrbproduct analysis for trigger=1311764

batgrbproduct Analysis for Trigger=1311764

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): Thu Jun 19 20:44:33 EDT 2025
             Host Name: batproc1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1311764
======================================================================

  Trigger: 01311764      Segment: 000

  BAT Trigger Time: 768522846.208   [s; MET]
      Trigger Stop: 768522847.232   [s; MET]
               UTC: 2025-05-09T22:33:30.632640    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 46.4548923274837   Dec: -38.8534416712175  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    12.76
     Image Trigger?:     NO
     Rate S/N Ratio:     33.1511689085016  [ if not an image trigger ]
     Image S/N Ratio:    12.76

  Flight Position:   [ source = BAT ]
    RA: 46.4548923274837   Dec: -38.8534416712175  [deg; J2000]

  Ground Position:   [ source = BAT pre-slew burst ]
    RA: 46.4522907344857   Dec: -38.8551097964994  [deg; J2000]  
        { 03h 05m 48.5s , -38d 51' 18.4" }
         +/- 0.749395237662782 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.21891126881961 [arcmin] (formal 1-sigma fit error)
    SNR: 45.9306685950901
 
  Angular difference between Flight and Ground position is 0.157461 arcmin
 
  Partial Coding Fraction: 0.96875    [ including projection effects ]

  Duration
     T90: 54.3279999494553 +/- 11.5425226062181
        Measured from: -1
                   to: 53.3279999494553     [s; relative to TRIGTIME]
     T50: 16.9879999160767 +/- 2.16260587892502
        Measured from: 2.71600008010864
                   to: 19.7039999961853     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 0.416000008583069     
                   to: 1.41600000858307     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -2.84799993038177     
                   to: 71.4640001058578     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     1.199588   1.632114   1.061012   0.313841
           0.052282   0.054801   0.047245   0.039634 [error]
 Peak      0.062163   0.091098   0.087445   0.024896
           0.006934   0.007551   0.006986   0.005423 [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 3.45e-07 6.17e-07 8.47e-07 2.40e-06 2.44e-06 4.21e-06   erg/cm2
              Error 2.59e-08 2.70e-08 4.67e-08 2.94e-07 1.11e-07 3.26e-07   erg/cm2
Peak flux Power-law 4.90e-01 6.02e-01 5.38e-01 8.29e-01 1.92e+00 2.46e+00   ph/cm2/s
              Error 7.95e-02 5.97e-02 5.38e-02 1.76e-01 1.67e-01 2.29e-01   ph/cm2/s
 
Fluence   Cutoff-PL 3.35e-07 6.26e-07 8.55e-07 1.87e-06 2.41e-06 3.69e-06   erg/cm2
              Error 3.12e-08 2.37e-08 4.91e-08 7.32e-07 1.27e-07 6.57e-07   erg/cm2
Peak flux Cutoff-PL 4.55e-01 6.19e-01 5.58e-01 5.68e-01 1.89e+00 2.20e+00   ph/cm2/s
              Error 9.54e-02 6.69e-02 6.31e-02 2.84e-01 1.72e-01 3.46e-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    1.545    0.077    -      -           3.49e-03 1.46e-04   57.330 57
CPL   1.388    0.254     196.4  -49.1      4.17e-03 1.25e-03   56.470 56
 
 
=== 1-s peak spectral analysis ===
 
Model Ph_index Ph_90err Epeak  Epeak_90err Norm     Nomr_90err chi2   dof
PL    1.164    0.148    -      -           1.64e-02 1.40e-03   73.960 57
CPL   0.819    0.511     183.7    0.0      2.40e-02 1.50e-02   72.770 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: 34.624000 sec.
T50 in the 50-300 keV band: 12.096000 sec.

 
=== Table of the duration information ==
 
        Value   tstart    tstop
T100   74.312   -2.848   71.464
T90    54.328   -1.000   53.328
T50    16.988    2.716   19.704
Peak    1.000    0.416    1.416

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
   46.4523   -38.8551   0.0042     9.4275    53.9425         2.7331857     45.931 TRIG_01311764                 
 
Foreground time interval of the image:
 -2.848  15.493 (delta_t =  18.341 [sec])
Background time interval of the image:
-239.208  -2.848 (delta_t = 236.360 [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

8 ms binning

From T100_start-3 s to T100_start+3 s

2 ms binning

From T100_start-1 s to T100_start+1 s

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   -2.848 sec. to   71.464 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.54478     ( -0.0768741   0.077158 )
Norm@50keV  : 3.48761E-03    ( -0.000146047   0.000145563 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   57.33     using 59 bins.
 Reduced chi-squared = 1.00579
# Null hypothesis probability of 4.63e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 74.31 sec: 0.440859 ( -0.018817  0.018851 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.44195e-06 ( -1.10926e-07  1.11496e-07 ) ergs/cm2

Cutoff power-law model

Time interval is from   -2.848 sec. to   71.464 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.38784     ( -0.306578   0.201806 )
Epeak [keV] : 196.447      ( -98.2328 -196.525 )
Norm@50keV  : 4.17499E-03    ( -0.000798757   0.00170632 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   56.47     using 59 bins.
 Reduced chi-squared = 1.00839
# Null hypothesis probability of 4.57e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 74.31 sec: 0.436565 ( -0.020338  0.020346 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.408e-06 ( -1.27515e-07  1.26878e-07 ) ergs/cm2

Band function

Time interval is from   -2.848 sec. to   71.464 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]    : 14.6258  (  )
R^2/D10^2   : 5.22856E-02  (   )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic  : Chi-Squared                  188.23     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 6.17e-16 with 57 degrees of freedom
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  1.747e-07   1.479e-08
25- 50  6.778e-07   3.641e-08
50-150  9.755e-07   7.988e-08
15-150  1.828e-06   8.992e-08

Thermal bremsstrahlung (OTTB)

 
 
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT [keV]    : 200.000       (-33.793      -200)
Norm        : 1.78548       (-0.0728144     0.0728144)
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   57.15     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 4.70e-01 with 57 degrees of freedom
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  3.308e-07   1.382e-08
25- 50  6.363e-07   2.716e-08
50-150  1.396e-06   6.131e-08
15-150  2.363e-06   1.144e-07

Double BB

 
 
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT1 [keV]   : 7.70283        (-1.01327      1.06716)
R1^2/D10^2  : 0.347517        (-0.118304      0.207961)
kT2 [keV]   : 29.9927        (-4.91385      7.9122)
R2^2/D10^2  : 3.30279E-03    (-0.00176745   0.00293194)
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   56.83     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 4.07e-01 with 55 degrees of freedom
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  3.035e-07   3.879e-08
25- 50  6.535e-07   6.558e-08
50-150  1.456e-06   3.429e-07
15-150  2.413e-06   4.161e-07

Peak spectrum fit

Power-law model

Time interval is from    0.416 sec. to    1.416 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.16408     ( -0.148673   0.147119 )
Norm@50keV  : 1.64145E-02    ( -0.00140307   0.00140294 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   73.96     using 59 bins.
 Reduced chi-squared = 1.29754
# Null hypothesis probability of 6.49e-02 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 1.91756 ( -0.16675  0.16691 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.68287e-07 ( -1.62077e-08  1.63548e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from    0.416 sec. to    1.416 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 0.818759     ( -0.606261   0.415722 )
Epeak [keV] : 183.658      ( -183.658 -183.658 )
Norm@50keV  : 2.40013E-02    ( -0.0085651   0.0214277 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   72.77     using 59 bins.
 Reduced chi-squared = 1.29946
# Null hypothesis probability of 6.54e-02 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 1.89199 ( -0.17175  0.17155 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.82159e-08 ( -1.0536e-08  1.31306e-08 ) ergs/cm2

Band function

Time interval is from    0.416 sec. to    1.416 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]    : 19.3900  (-2.20499  2.54211)
R^2/D10^2   : 9.87918E-02  (-0.0323899   0.0475074)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   97.62     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 6.54e-04 with 57 degrees of freedom
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  7.246e-09   1.244e-09
25- 50  3.535e-08   4.515e-09
50-150  9.805e-08   1.489e-08
15-150  1.406e-07   1.640e-08

Thermal bremsstrahlung (OTTB)

 
 
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT [keV]    : 200.000       (-20.4301      -200)
Norm        : 7.82703       (-0.684693     0.684693)
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   90.84     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 2.91e-03 with 57 degrees of freedom
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  1.949e-08   2.130e-09
25- 50  3.750e-08   1.292e-08
50-150  8.224e-08   3.727e-08
15-150  1.392e-07   4.298e-08

Double BB

 
 
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT1 [keV]   : 7.08337        (-1.81678      2.49773)
R1^2/D10^2  : 1.46344        (-0.897572      2.64237)
kT2 [keV]   : 29.2555        (-5.63565      11.0778)
R2^2/D10^2  : 2.23127E-02    (-0.014382   0.0237382)
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   70.25     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 8.07e-02 with 55 degrees of freedom
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  1.497e-08   7.006e-09
25- 50  3.525e-08   1.239e-08
50-150  1.159e-07   5.009e-08
15-150  1.661e-07   6.393e-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: 1.38999     ( -0.0629309   0.0628506 )
Norm@50keV  : 9.65665E-03    ( -0.000329769   0.000329698 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   48.62     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 7.77e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 18.34 sec: 1.17336 ( -0.0420768  0.0421436 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.71482e-06 ( -6.4216e-08  6.44027e-08 ) ergs/cm2

Cutoff power-law model

Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.21797     ( -0.247804   0.198568 )
Epeak [keV] : 238.752      ( -110.44 -238.757 )
Norm@50keV  : 1.16863E-02    ( -0.00221334   0.00358132 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   47.06     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 7.97e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 18.34 sec: 1.16157 ( -0.04483  0.04487 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.69292e-06 ( -7.17681e-08  7.13426e-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)  = 6.17e-07
S(50-100 keV) = 8.47e-07

T90 vs. Hardness ratio plot

T90                                   = 54.3279999494553 sec.
Hardness ratio (energy fluence ratio) = 1.37277

Color vs. Color plot

Count Ratio  (25-50 keV) / (15-25 keV) = 1.36056
Count Ratio (50-100 keV) / (15-25 keV) = 0.88448

Mask shadow pattern

IMX = 9.773204041814562E-02, IMY = -1.342329241330164E-01

TIME vs. PHA plot around the trigger time

TIME vs. DetID plot around the trigger time

100 us light curve (15-350 keV)

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:
-239.208000 -2.848000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 33.5492 -69.8670    2.4  39.8   82.0   6.6914   4.8 ------	UNKNOWN                       
101.5557 -34.4284    2.6  50.1    9.1   2.8236   4.4 ------	UNKNOWN                       
 97.5924 -27.8118    3.4  48.5   -0.5   1.9842   3.4 ------	UNKNOWN                       
101.3767 -26.6342    2.6  52.1   -0.6   3.0666   4.5 ------	UNKNOWN

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

Time interval of the image:
-2.848000 15.492600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 46.4523 -38.8551    0.3   9.4   53.9   2.7333  45.9 ------	UNKNOWN                       
351.7870  -4.2994    2.5  53.6 -173.5   0.8282   4.7  555.8	UNKNOWN                       
 89.4780  -8.0041    2.4  49.9  -28.6   0.6971   4.9 ------	UNKNOWN

Post-slew image of 15-350 keV band

Time interval of the image:
58.492600 677.592600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
338.8346 -40.8304    2.4  50.6  154.3  13.6907   4.7 ------	UNKNOWN                       
  1.5031  -6.0878    1.8  52.1 -153.5  15.1801   6.4  376.2	UNKNOWN

Plot creation:
Fri Jun 20 01:40:16 EDT 2025