batgrbproduct analysis for trigger=1500287

batgrbproduct Analysis for Trigger=1500287

Analysis Summary

Notes:

1) No attempt has been made to eliminate the non-significant decimal places.
2) This batgrbproduct analysis is done of the amount of data for this trigger downloaded to date.
3) This batgrbproduct analysis is using the flight position for the mask-weighting calculation.
4) This page will be updated for up to 15 downlinks after the trigger.

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.48
    Process Start Time (local time): Sat Mar 14 09:11:24 EDT 2026
             Host Name: batproc1
   Current Working Dir: /local/data/bat1/prebascript/trigger1500287/GCN5_download_cron
======================================================================

  Trigger: 01500287      Segment: 000

  BAT Trigger Time: 795093024   [s; MET]
      Trigger Stop: 795093088   [s; MET]
               UTC: 2026-03-13T11:09:46.621040    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 352.882977707216   Dec: -2.98881362933404  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    11.25
     Image Trigger?:     YES
     Rate S/N Ratio:     0  [ if not an image trigger ]
     Image S/N Ratio:    11.25

  Flight Position:   [ source = BAT ]
    RA: 352.882977707216   Dec: -2.98881362933404  [deg; J2000]

  Ground Position:   [ source = BAT pre-slew burst ]
    RA: 352.881797873826   Dec: -2.99614064102188  [deg; J2000]  
        { 23h 31m 31.6s , -02d 59' 46.1" }
         +/- 2.12893866633875 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.754028665249869 [arcmin] (formal 1-sigma fit error)
    SNR: 10.3350808940341
 
  Angular difference between Flight and Ground position is 0.445268 arcmin
 
  Partial Coding Fraction: 0.2734375    [ including projection effects ]

  Duration
     T90: 162.212000012398 +/- 7.4979462883115
        Measured from: 11.7322001457214
                   to: 173.944200158119     [s; relative to TRIGTIME]
     T50: 122.191999912262 +/- 23.820777177561
        Measured from: 32.7482001781464
                   to: 154.940200090408     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 41.2522000074387     
                   to: 42.2522000074387     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: 4.09220004081726     
                   to: 180.168200016022     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     5.833962   1.699306   1.178835   0.138575
           0.173017   0.168136   0.149207   0.120131 [error]
 Peak      0.098302   0.036985   0.037912  -0.008665
           0.014336   0.013125   0.011840   0.008681 [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 1.10e-06 1.02e-06 6.52e-07 6.44e-07 3.03e-06 3.41e-06   erg/cm2
              Error -------- -------- -------- -------- -------- --------   erg/cm2
Peak flux Power-law 1.52e+00 8.62e-02 1.67e-03 3.29e-05 1.61e+00 1.61e+00   ph/cm2/s
              Error 3.70e-01 1.20e-01 1.18e-02 1.15e-03 4.17e-01 4.17e-01   ph/cm2/s
 
Fluence   Cutoff-PL 1.12e-06 1.01e-06 6.29e-07 5.92e-07 3.01e-06 3.35e-06   erg/cm2
              Error -------- -------- -------- -------- -------- --------   erg/cm2
Peak flux Cutoff-PL 1.51e+00 7.48e-02 1.20e-03 1.97e-05 1.59e+00 1.59e+00   ph/cm2/s
              Error 3.69e-01 1.32e-01 1.19e-02 1.18e-03 4.13e-01 4.17e-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    2.639    0.000    -      -           1.66e-03 0.00e+00  168.480 57
CPL   1.850    0.000      12.4    0.0      3.59e-03 0.00e+00  175.960 56
 
 
=== 1-s peak spectral analysis ===
 
Model Ph_index Ph_90err Epeak  Epeak_90err Norm     Nomr_90err chi2   dof
PL    6.687    2.261    -      -           1.95e-04 8.97e-04   60.490 57
CPL   1.783    0.000       6.1    0.0      3.23e-02 0.00e+00   71.320 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: 0.000000 sec.
T50 in the 50-300 keV band: 0.000000 sec.

 
=== Table of the duration information ==
 
        Value   tstart    tstop
T100  176.076    4.092  180.168
T90   162.212   11.732  173.944
T50   122.192   32.748  154.940
Peak    1.000   41.252   42.252

Click here for the BAT GCN circular template

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

Image

Pre-slew 15-350 keV image (Event data; bkg subtracted)

#   RAcent  DECcent POSerr  Theta    Phi     Peak Cts     SNR  Name
  352.8818  -2.9961 0.0184   47.4 -149.3       6.5791    10.3  TRIG_01500287       
------------------------------------------
 
Foreground time interval of the image:
  4.092  54.890 (delta_t =  50.798 [sec])
 56.000 155.801 (delta_t =  99.801 [sec])
Background time interval of the image:
-67.499 -55.880 (delta_t =  11.619 [sec])
-55.000   4.092 (delta_t =  59.092 [sec])

Lightcurves

Notes:

1) All plots contain as much data as has been downloaded to date.
2) The mask-weighted light curves are using the flight position.
3) Multiple plots of different time binning/intervals are shown to cover all scenarios of short/long GRBs, rate/image triggers, and real/false positives.
4) 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.
5) 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.
6) 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)

Spectra

Notes:

1) The fitting includes the systematic errors.
2) For long bursts, a spectral fit of 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.
4) For short bursts (T90<1sec), the specrtum is also fit with Blackbody, OTTB, and Double Blackbody.

Time averaged spectrum fit using the pre-slew DRM

Power-law model

Multiple GTIs in the spectrum
tstart tstop
4.092200 54.890000
56.000000 180.168200
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 2.63942     (     )
Norm@50keV  : 1.66221E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =         168.48 using 59 PHA bins.
# Reduced chi-squared =         2.9559 for     57 degrees of freedom 
# Null hypothesis probability =   5.965604e-13
 
Photon flux (15-150 keV)    in 175 sec: 0.356541 (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.03152e-06 ( 0  0 ) ergs/cm2

Cutoff power-law model

Multiple GTIs in the spectrum
tstart tstop
4.092200 54.890000
56.000000 180.168200
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.85017     (     )
Epeak [keV] : 12.3746      (   )
Norm@50keV  : 3.58830E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =         175.96 using 59 PHA bins.
# Reduced chi-squared =         3.1421 for     56 degrees of freedom 
# Null hypothesis probability =   2.561485e-14
 
Photon flux (15-150 keV)    in 175 sec: 0.356296 (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.00984e-06 ( 0  0 ) ergs/cm2

Band function

Multiple GTIs in the spectrum
tstart tstop
4.092200 54.890000
56.000000 180.168200
 
Spectral model in the Band function:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
alpha       : -1.98037   (     )
beta        : -9.37167    (     )
Epeak [keV] : 2.06060      (   )
Norm@50keV   : 3.09779E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =         174.48 using 59 PHA bins.
# Reduced chi-squared =         3.1724 for     55 degrees of freedom 
# Null hypothesis probability =   2.375168e-14
 
Photon flux (15-150 keV)    in 175 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]    : 11.1492  (  )
R^2/D10^2   : 8.73901E-02  (   )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared =         220.25 using 59 PHA bins.
# Reduced chi-squared =         3.8640 for     57 degrees of freedom 
# Null hypothesis probability =   4.892593e-21
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  3.982e-07   7.753e-08
25- 50  1.146e-06   1.491e-07
50-150  8.127e-07   2.003e-07
15-150  2.357e-06   3.098e-07

Thermal bremsstrahlung (OTTB)

XSPEC12>exit
 XSPEC: quit
 
 
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT [keV]    : 45.8853       (      )
Norm        : 1.88155       (     )
------------------------------------------------------------
 Reduced chi-squared = 
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  7.881e-07   1.072e-07
25- 50  1.096e-06   1.331e-07
50-150  9.794e-07   2.466e-07
15-150  2.864e-06   3.500e-07

Double BB

XSPEC12>exit
 XSPEC: quit
 
 
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT1 [keV]   : 1.71551        (-0.20193      0.238645)
R1^2/D10^2  : 5840.60        (-4250.48      16561.4)
kT2 [keV]   : 14.3720        (-1.62345      1.86203)
R2^2/D10^2  : 2.87364E-02    (-0.0109004   0.0168914)
------------------------------------------------------------
 Reduced chi-squared = 
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  2.438e-06   1.210e-06
25- 50  8.616e-07   1.756e-07
50-150  1.151e-06   2.742e-07
15-150  4.451e-06   1.264e-06

Peak spectrum fit

Power-law model

Time interval is from   41.252 sec. to   42.252 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 6.68707     ( -2.22887   2.29274 )
Norm@50keV  : 1.94640E-04    ( -0.000193665   0.00160077 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          60.49 using 59 PHA bins.
# Reduced chi-squared =          1.061 for     57 degrees of freedom 
# Null hypothesis probability =   3.508580e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.61027 ( -0.42081  0.413795 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.69418e-08 ( -1.36267e-08  1.48015e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from   41.252 sec. to   42.252 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.78334     (     )
Epeak [keV] : 6.05575      (   )
Norm@50keV  : 3.22640E-02    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          71.32 using 59 PHA bins.
# Reduced chi-squared =          1.274 for     56 degrees of freedom 
# Null hypothesis probability =   8.148453e-02
 
Photon flux (15-150 keV)    in 1 sec: 1.58918 ( -0.39914  0.42609 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.67768e-08 ( 0  0 ) ergs/cm2

Band function

Time interval is from   41.252 sec. to   42.252 sec.
 
Spectral model in the Band function:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
alpha       : 3.72251   ( -3.72303   -3.72303 )
beta        : -6.75148    ( -2.26336   2.28278 )
Epeak [keV] : 2.23638      ( 6.57997 -2.23638 )
Norm@50keV   : 8.30223E+07    ( -8.21904e+07   2.246e+08 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          60.50 using 59 PHA bins.
# Reduced chi-squared =          1.100 for     55 degrees of freedom 
# Null hypothesis probability =   2.841065e-01
 
Photon flux (15-150 keV)    in 1 sec:  (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2

Single BB

 XSPEC: quit
 
 
Spectral model blackbody:
------------------------------------------------------------
Parameters  : value    Lower 90%  Upper 90%
kT [keV]    : 1.86682  (-0.455698  0.716312)
R^2/D10^2   : 8628.14  (-8533.31   127398)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
 Reduced chi-squared = 
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  3.807e-08   2.432e-08
25- 50  1.611e-09   1.481e-09
50-150  1.316e-13   3.995e-13
15-150  3.968e-08   2.548e-08

Thermal bremsstrahlung (OTTB)

XSPEC12>exit
 XSPEC: quit
 
 
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT [keV]    : 3.11341       (-1.0374      2.16842)
Norm        : 3017.47       (-3088.92     35572.1)
------------------------------------------------------------
 Reduced chi-squared = 
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  4.260e-08   2.460e-08
25- 50  1.465e-09   9.440e-10
50-150  3.622e-13   4.988e-13
15-150  4.407e-08   2.449e-08

Double BB

XSPEC12>exit
 XSPEC: quit
 
 
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT1 [keV]   : 1.58162        (-0.411495      0.53842)
R1^2/D10^2  : 3.69393E+04        (-36569      1.08452e+06)
kT2 [keV]   : 13.0594        (-3.96979      4.32387)
R2^2/D10^2  : 0.145495    (-0.106986   0.421206)
------------------------------------------------------------
 Reduced chi-squared = 
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  3.972e-08   2.135e-08
25- 50  1.847e-08   1.185e-08
50-150  1.969e-08   1.555e-08
15-150  7.788e-08   4.128e-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: 2.65415     (     )
Norm@50keV  : 1.51853E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =         161.23 using 59 PHA bins.
# Reduced chi-squared =         2.8286 for     57 degrees of freedom 
# Null hypothesis probability =   6.833512e-12
 
Photon flux (15-150 keV)    in 150.6 sec: 0.328904 (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.3944e-06 ( 0  0 ) ergs/cm2

Cutoff power-law model

Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.69663     (     )
Epeak [keV] : 33.3172      (   )
Norm@50keV  : 3.10720E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =         171.81 using 59 PHA bins.
# Reduced chi-squared =         3.0680 for     56 degrees of freedom 
# Null hypothesis probability =   1.082855e-13
 
Photon flux (15-150 keV)    in 150.6 sec: 0.329759 (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.3624e-06 ( 0  0 ) ergs/cm2

Band function

 
Spectral model in the Band function:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
alpha       : -1.67251   (     )
beta        : -9.20884    (     )
Epeak [keV] : 22.6903      (   )
Norm@50keV   : 3.87070E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =         169.75 using 59 PHA bins.
# Reduced chi-squared =         3.0863 for     55 degrees of freedom 
# Null hypothesis probability =   1.236341e-13
 
Photon flux (15-150 keV)    in 150.6 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)  = 1.02e-06
S(50-100 keV) = 6.52e-07

T90 vs. Hardness ratio plot

T90                                   = 162.212000012398 sec.
Hardness ratio (energy fluence ratio) = 0.639216

Color vs. Color plot

Count Ratio  (25-50 keV) / (15-25 keV) = 0.291278
Count Ratio (50-100 keV) / (15-25 keV) = 0.202064

Mask shadow pattern

IMX = -9.340864148309894E-01, IMY = 5.546808034903962E-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:
-67.499380 -55.880000
-55.000000 4.092200
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.4711  35.4512    9.6  53.3   10.6   0.6239   1.2    6.6	Her X-1                       
288.6401  11.0967    0.0  36.0  -41.5  -0.1124  -0.5   13.0	GRS 1915+105                  
299.5943  35.2178    0.7  17.1    2.3   2.1229  16.1    1.0	Cyg X-1                       
308.2943  40.8408    4.8  12.4   32.6  -0.3085  -2.4   10.7	Cyg X-3                       
326.2751  38.3419    7.2   7.6  118.7   0.2132   1.6    5.0	Cyg X-2                       
347.6818  40.3143    2.3  23.4  141.3   0.7525   5.1 ------	UNKNOWN

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

Time interval of the image:
4.092200 54.890000
56.000000 155.800600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.4492  35.4497   17.4  53.3   10.6  -0.7981  -0.7    6.4	Her X-1                       
288.6435  11.0662   12.1  36.0  -41.5   0.3744   1.0   11.6	GRS 1915+105                  
299.4058  35.0588    0.0  17.2    1.7   0.6270   2.7   12.5	Cyg X-1                       
308.0314  40.8322    5.3  12.5   32.0   0.5228   2.2    8.1	Cyg X-3                       
326.0387  38.4826    7.8   7.6  116.9   0.3434   1.5   11.5	Cyg X-2                       
313.3798  66.5329    2.3  34.0   73.5   2.4564   5.0 ------	UNKNOWN                       
356.1746  55.4440    2.0  33.9  115.1   2.5253   5.7 ------	UNKNOWN                       
354.5745  38.7651    2.4  28.5  146.1   1.4613   4.7 ------	UNKNOWN                       
352.8818  -2.9962    1.1  47.4 -149.3   6.5801  10.4  463.2	UNKNOWN                       
303.7360   1.3200    2.3  34.9  -72.5   2.6395   4.9 ------	UNKNOWN

Post-slew image of 15-350 keV band

Time interval of the image:
176.300600 395.600600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
288.7378  10.9064    5.1  38.0  -39.9   1.4232   2.3    4.3	GRS 1915+105                  
299.5853  35.2134    0.7  18.5   -0.1   6.4490  17.2    0.8	Cyg X-1                       
308.3137  41.0947    4.6  13.1   27.1   0.9459   2.5   12.6	Cyg X-3                       
326.2253  38.2465    9.1   5.6  115.6   0.4707   1.3    5.2	Cyg X-2                       
 20.4742  22.2173    2.2  52.2  165.9   6.1795   5.2 ------	UNKNOWN                       
263.1744  21.6015    2.8  52.8   -8.1   3.7822   4.1 ------	UNKNOWN                       
352.8928  -3.0319    1.9  47.0 -145.4   5.6462   6.2  463.4	UNKNOWN

Plot creation:
Sat Mar 14 09:15:10 EDT 2026