batgrbproduct analysis for trigger=1426088
batgrbproduct Analysis for Trigger=1426088
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): Wed Dec 24 17:44:20 EST 2025
Host Name: batproc1
Current Working Dir: /local/data/bat1/prebascript/trigger1426088/batgroup_hand_proc
======================================================================
Trigger: 01426088 Segment: 000
BAT Trigger Time: 787987508.864 [s; MET]
Trigger Stop: 787987512.96 [s; MET]
UTC: 2025-12-21T05:24:31.965060 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 101.408459383592 Dec: 0.729192803908108 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.35
Image Trigger?: NO
Rate S/N Ratio: 13.9642400437689 [ if not an image trigger ]
Image S/N Ratio: 7.35
Flight Position: [ source = BAT ]
RA: 101.408459383592 Dec: 0.729192803908108 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 101.422318443239 Dec: 0.737713396285322 [deg; J2000]
{ 06h 45m 41.4s , +00d 44' 15.8" }
+/- 1.41412613105958 [arcmin] (estimated 90% radius based on SNR)
+/- 0.547047653536818 [arcmin] (formal 1-sigma fit error)
SNR: 18.5410921399077
Angular difference between Flight and Ground position is 0.976070 arcmin
Partial Coding Fraction: 0.4296875 [ including projection effects ]
Duration
T90: 56.864000082016 +/- 7.0481272127273
Measured from: -35.5920000076294
to: 21.2720000743866 [s; relative to TRIGTIME]
T50: 20.9759999513626 +/- 11.2270445163436
Measured from: -15.1439999341965
to: 5.83200001716614 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 2.90799999237061
to: 3.90799999237061 [s; relative to TRIGTIME]
Total Fluence
Measured from: -38.1039999723434
to: 27.7360000610352 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.608569 1.087964 1.015174 0.275365
0.075700 0.080363 0.069525 0.057548 [error]
Peak 0.026973 0.045111 0.057839 0.019973
0.009761 0.010305 0.009590 0.007883 [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 2.06e-07 4.41e-07 7.43e-07 2.86e-06 2.04e-06 4.25e-06 erg/cm2
Error 2.98e-08 3.86e-08 6.59e-08 5.65e-07 1.67e-07 6.04e-07 erg/cm2
Peak flux Power-law 2.49e-01 3.30e-01 3.21e-01 5.59e-01 1.09e+00 1.46e+00 ph/cm2/s
Error 1.12e-01 8.99e-02 7.18e-02 2.78e-01 2.38e-01 3.25e-01 ph/cm2/s
Fluence Cutoff-PL 1.85e-07 4.60e-07 7.78e-07 1.49e-06 1.98e-06 2.91e-06 erg/cm2
Error 3.66e-08 4.51e-08 7.71e-08 1.10e-06 1.81e-07 1.19e-06 erg/cm2
Peak flux Cutoff-PL 2.47e-01 3.29e-01 3.22e-01 5.60e-01 1.08e+00 1.46e+00 ph/cm2/s
Error 1.29e-01 9.19e-02 8.28e-02 4.70e-01 2.38e-01 3.99e-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 1.248 0.131 - - 3.10e-03 2.35e-04 58.350 57
CPL 0.748 0.572 135.3 -44.2 5.34e-03 3.53e-03 55.800 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.039 0.381 - - 9.40e-03 2.00e-03 58.780 57
CPL 1.033 2.593 9998.6 0.0 9.46e-03 1.40e-02 58.780 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: 55.488000 sec.
T50 in the 50-300 keV band: 16.384000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 65.840 -38.104 27.736
T90 56.864 -35.592 21.272
T50 20.976 -15.144 5.832
Peak 1.000 2.908 3.908
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
101.4223 +0.7377 0.0103 28.7 82.0 2.9995 18.5 TRIG_01426088
------------------------------------------
Foreground time interval of the image:
-38.104 27.736 (delta_t = 65.840 [sec])
Background time interval of the image:
-239.864 -38.104 (delta_t = 201.760 [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
Time interval is from -38.104 sec. to 27.736 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.24811 ( -0.131383 0.129703 )
Norm@50keV : 3.09614E-03 ( -0.00023458 0.000234535 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.35 using 59 PHA bins.
# Reduced chi-squared = 1.024 for 57 degrees of freedom
# Null hypothesis probability = 4.255359e-01
Photon flux (15-150 keV) in 65.84 sec: 0.366078 ( -0.0290119 0.0290785 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.04114e-06 ( -1.67108e-07 1.6781e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -38.104 sec. to 27.736 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.747673 ( -0.610204 0.533797 )
Epeak [keV] : 135.317 ( -47.0122 -135.317 )
Norm@50keV : 5.33532E-03 ( -0.00228815 0.00478166 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.80 using 59 PHA bins.
# Reduced chi-squared = 0.9964 for 56 degrees of freedom
# Null hypothesis probability = 4.823649e-01
Photon flux (15-150 keV) in 65.84 sec: 0.358227 ( -0.030303 0.030269 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.98324e-06 ( -1.82186e-07 1.80704e-07 ) ergs/cm2
Band function
Time interval is from -38.104 sec. to 27.736 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.520656 ( -0.588351 0.521602 )
beta : -1.58816 ( 1.58952 0.348383 )
Epeak [keV] : 100.731 ( -50.4948 365.875 )
Norm@50keV : 7.13447E-03 ( -0.00372711 0.167932 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.28 using 59 PHA bins.
# Reduced chi-squared = 1.005 for 55 degrees of freedom
# Null hypothesis probability = 4.641389e-01
Photon flux (15-150 keV) in 65.84 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] : 18.2340 (-1.67561 1.91454)
R^2/D10^2 : 2.27383E-02 (-0.00654874 0.00885911)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 80.01 using 59 PHA bins.
# Reduced chi-squared = 1.404 for 57 degrees of freedom
# Null hypothesis probability = 2.387116e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 9.924e-08 1.458e-08
25- 50 4.634e-07 5.563e-08
50-150 1.122e-06 1.534e-07
15-150 1.685e-06 1.649e-07
Thermal bremsstrahlung (OTTB)
XSPEC12>exit
XSPEC: quit
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 (-18.5804 -200)
Norm : 1.53585 (-0.11799 0.11799)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.518e-07 2.637e-08
25- 50 4.843e-07 4.704e-08
50-150 1.062e-06 3.686e-07
15-150 1.798e-06 4.918e-07
Double BB
XSPEC12>exit
XSPEC: quit
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 8.53841 (-3.72349 4.51703)
R1^2/D10^2 : 0.149682 (-0.0762933 0.416358)
kT2 [keV] : 28.8360 (-9.45069 102.878)
R2^2/D10^2 : 3.82350E-03 (-0.002603 0.00754932)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.693e-07 9.200e-08
25- 50 4.688e-07 2.261e-07
50-150 1.299e-06 6.444e-07
15-150 1.937e-06 8.641e-07
Peak spectrum fit
Power-law model
Time interval is from 2.908 sec. to 3.908 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.03949 ( -0.39163 0.370408 )
Norm@50keV : 9.40402E-03 ( -0.00201246 0.00198721 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.78 using 59 PHA bins.
# Reduced chi-squared = 1.031 for 57 degrees of freedom
# Null hypothesis probability = 4.102237e-01
Photon flux (15-150 keV) in 1 sec: 1.08531 ( -0.237227 0.238719 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.00304e-07 ( -2.21961e-08 2.23595e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 2.908 sec. to 3.908 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.03348 ( -1.46934 3.7175 )
Epeak [keV] : 9998.57 ( -9998.57 -9998.57 )
Norm@50keV : 9.45844E-03 ( -0.00198332 0.026056 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.78 using 59 PHA bins.
# Reduced chi-squared = 1.050 for 56 degrees of freedom
# Null hypothesis probability = 3.741649e-01
Photon flux (15-150 keV) in 1 sec: 1.08363 ( -0.235285 0.23994 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.00316e-07 ( -2.24617e-08 2.2304e-08 ) ergs/cm2
Band function
Time interval is from 2.908 sec. to 3.908 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 5.00000 ( -5 -5 )
beta : -1.13084 ( -0.460431 0.432032 )
Epeak [keV] : 28.6971 ( -28.6956 10.8164 )
Norm@50keV : 303.829 ( -62.6745 2.77743e+06 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.20 using 59 PHA bins.
# Reduced chi-squared = 1.058 for 55 degrees of freedom
# Null hypothesis probability = 3.582780e-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] : 26.3244 (-6.47333 9.73015)
R^2/D10^2 : 2.21221E-02 (-0.0134369 0.0306276)
(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 2.589e-09 1.307e-09
25- 50 1.507e-08 6.110e-09
50-150 7.674e-08 3.227e-08
15-150 9.440e-08 3.473e-08
Thermal bremsstrahlung (OTTB)
XSPEC12>exit
XSPEC: quit
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 (-64.1645 -200)
Norm : 4.51314 (-0.979433 0.979433)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.124e-08 6.660e-09
25- 50 2.162e-08 1.262e-08
50-150 4.741e-08 2.777e-08
15-150 8.027e-08 4.702e-08
Double BB
XSPEC12>exit
XSPEC: quit
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 5.92548 (-1.97165 3.27583)
R1^2/D10^2 : 1.75428 (-1.51913 5.40932)
kT2 [keV] : 34.1764 (-9.7449 22.9447)
R2^2/D10^2 : 9.10687E-03 (-0.00689131 0.0130321)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 9.567e-09 5.970e-09
25- 50 1.772e-08 9.475e-09
50-150 7.760e-08 4.557e-08
15-150 1.049e-07 5.660e-08
Plot creation:
Wed Dec 24 17:51:51 EST 2025