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 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): Thu Sep 25 09:49:20 EDT 2025
Host Name: batproc1
Current Working Dir: /local/data/bat1/prebascript/trigger1351790/GCN5_download_cron
======================================================================
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: 51.9075634228292 Dec: 74.6653056137565 [deg; J2000]
{ 03h 27m 37.8s , +74d 39' 55.1" }
+/- 1.68657173002263 [arcmin] (estimated 90% radius based on SNR)
+/- 0.782197329723424 [arcmin] (formal 1-sigma fit error)
SNR: 14.4153697035566
Angular difference between Flight and Ground position is 1.049534 arcmin
Partial Coding Fraction: 0.1230469 [ including projection effects ]
Duration
T90: 26.527999997139 +/- 3.71814147999738
Measured from: -8.19199991226196
to: 18.336000084877 [s; relative to TRIGTIME]
T50: 14.3359999656677 +/- 2.71369857181295
Measured from: -0.639999866485596
to: 13.6960000991821 [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 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.757894 1.140066 1.165762 0.436935
0.118745 0.127137 0.105728 0.083052 [error]
Peak 0.040003 0.080734 0.077878 0.030985
0.022244 0.024403 0.020862 0.016555 [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 3.20e-07 5.99e-07 8.66e-07 2.66e-06 2.46e-06 4.44e-06 erg/cm2
Error 6.44e-08 7.43e-08 1.01e-07 6.74e-07 2.61e-07 7.30e-07 erg/cm2
Peak flux Power-law 6.06e-01 6.75e-01 5.37e-01 7.08e-01 2.08e+00 2.53e+00 ph/cm2/s
Error 3.54e-01 2.49e-01 1.65e-01 4.54e-01 6.77e-01 7.31e-01 ph/cm2/s
Fluence Cutoff-PL 2.83e-07 6.21e-07 9.21e-07 1.53e-06 2.43e-06 3.35e-06 erg/cm2
Error 7.96e-08 8.31e-08 1.27e-07 1.15e-06 2.67e-07 7.98e-07 erg/cm2
Peak flux Cutoff-PL 4.86e-01 7.20e-01 5.94e-01 3.17e-01 2.00e+00 2.12e+00 ph/cm2/s
Error 4.09e-01 2.95e-01 2.08e-01 5.35e-01 6.96e-01 9.11e-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 1.468 0.174 - - 8.62e-03 9.04e-04 66.190 57
CPL 0.965 0.687 117.9 -38.4 1.45e-02 1.18e-02 64.610 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.330 0.499 - - 1.73e-02 5.13e-03 48.310 57
CPL 0.372 5.806 92.6 -25.9 4.87e-02 1.25e+00 47.700 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: 21.632000 sec.
T50 in the 50-300 keV band: 13.760000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 29.920 -9.920 20.000
T90 26.528 -8.192 18.336
T50 14.336 -0.640 13.696
Peak 1.000 15.780 16.780
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
51.9076 +74.6653 0.0133 54.8 -165.2 3.9008 14.4 TRIG_01351790
------------------------------------------
Foreground time interval of the image:
-9.920 20.000 (delta_t = 29.920 [sec])
Background time interval of the image:
-239.664 -9.920 (delta_t = 229.744 [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 -9.920 sec. to 20.000 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.46823 ( -0.175515 0.172776 )
Norm@50keV : 8.62273E-03 ( -0.000905409 0.000903455 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 66.19 using 59 PHA bins.
# Reduced chi-squared = 1.161 for 57 degrees of freedom
# Null hypothesis probability = 1.894005e-01
Photon flux (15-150 keV) in 29.92 sec: 1.06753 ( -0.125289 0.126294 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.46064e-06 ( -2.61017e-07 2.61351e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -9.920 sec. to 20.000 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.965074 ( -0.793955 0.58104 )
Epeak [keV] : 117.859 ( -41.0815 -117.859 )
Norm@50keV : 1.45317E-02 ( -0.00641531 0.0171792 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.61 using 59 PHA bins.
# Reduced chi-squared = 1.154 for 56 degrees of freedom
# Null hypothesis probability = 2.012660e-01
Photon flux (15-150 keV) in 29.92 sec: 1.04152 ( -0.130052 0.13091 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.4291e-06 ( -2.67796e-07 2.66707e-07 ) ergs/cm2
Band function
Time interval is from -9.920 sec. to 20.000 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.965149 ( -0.501316 0.778645 )
beta : -10.0000 ( 10 1.06581e-14 )
Epeak [keV] : 117.851 ( -33.7437 -117.851 )
Norm@50keV : 1.45295E-02 ( -0.00645574 0.0172302 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.61 using 59 PHA bins.
# Reduced chi-squared = 1.175 for 55 degrees of freedom
# Null hypothesis probability = 1.761632e-01
Photon flux (15-150 keV) in 29.92 sec: 1.05304 ( ) 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] : 18.4452 (-2.13656 2.50542)
R^2/D10^2 : 6.01519E-02 (-0.0222519 0.0337232)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 81.79 using 59 PHA bins.
# Reduced chi-squared = 1.435 for 57 degrees of freedom
# Null hypothesis probability = 1.736459e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.216e-07 2.778e-08
25- 50 5.727e-07 1.053e-07
50-150 1.423e-06 2.308e-07
15-150 2.117e-06 2.985e-07
Thermal bremsstrahlung (OTTB)
XSPEC12>exit
XSPEC: quit
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 (-47.8142 -200)
Norm : 4.49124 (-0.468428 0.468428)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.347e-07 5.270e-08
25- 50 6.440e-07 1.503e-07
50-150 1.412e-06 5.923e-07
15-150 2.391e-06 8.159e-07
Double BB
XSPEC12>exit
XSPEC: quit
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 6.13818 (-1.82799 3.06798)
R1^2/D10^2 : 1.59072 (-1.20931 5.17262)
kT2 [keV] : 24.5743 (-4.30341 8.35006)
R2^2/D10^2 : 1.88545E-02 (-0.0125887 0.0160615)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.057e-07 1.617e-07
25- 50 5.935e-07 2.318e-07
50-150 1.533e-06 5.436e-07
15-150 2.432e-06 8.179e-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: 1.32967 ( -0.522797 0.475493 )
Norm@50keV : 1.73307E-02 ( -0.0051585 0.00509545 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 48.31 using 59 PHA bins.
# Reduced chi-squared = 0.8475 for 57 degrees of freedom
# Null hypothesis probability = 7.870549e-01
Photon flux (15-150 keV) in 1 sec: 2.07933 ( -0.668001 0.686719 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.70053e-07 ( -4.98884e-08 5.0068e-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: 0.372330 ( -3.79153 7.82001 )
Epeak [keV] : 92.5689 ( -40.7449 -92.5846 )
Norm@50keV : 4.86583E-02 ( -0.0486409 2.44776 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.70 using 59 PHA bins.
# Reduced chi-squared = 0.8518 for 56 degrees of freedom
# Null hypothesis probability = 7.771878e-01
Photon flux (15-150 keV) in 1 sec: 2.00101 ( -0.68509 0.70633 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.62893e-07 ( -5.5199e-08 5.2265e-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 : 4.36760 ( -4.36761 -4.36761 )
beta : -1.65461 ( -3.38084 0.680351 )
Epeak [keV] : 37.8633 ( -37.8538 200.94 )
Norm@50keV : 61.1547 ( -61.3136 25.2711 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.12 using 59 PHA bins.
# Reduced chi-squared = 0.8567 for 55 degrees of freedom
# Null hypothesis probability = 7.662579e-01
Photon flux (15-150 keV) in 1 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 1.6519e-07 ( -1.65183e-07 -4.978e-08 ) ergs/cm2
Single BB
XSPEC: quit
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 17.3065 (-4.74688 8.36841)
R^2/D10^2 : 0.154677 (-0.154403 0.339114)
(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 9.388e-09 5.888e-09
25- 50 4.213e-08 2.508e-08
50-150 9.059e-08 5.895e-08
15-150 1.421e-07 8.640e-08
Thermal bremsstrahlung (OTTB)
XSPEC12>exit
XSPEC: quit
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 199.361 (-109.318 -199.363)
Norm : 9.01657 (-2.62395 2.62415)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.245e-08 1.388e-08
25- 50 4.319e-08 2.643e-08
50-150 9.472e-08 5.790e-08
15-150 1.604e-07 9.605e-08
Double BB
XSPEC12>exit
XSPEC: quit
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 12.8981 (-11.7867 9.78819)
R1^2/D10^2 : 0.352312 (-0.348394 -0.348394)
kT2 [keV] : 80.7213 (-87.1034 -87.1034)
R2^2/D10^2 : 9.06949E-04 (-0.00070849 0.305245)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.352e-08 9.215e-09
25- 50 4.557e-08 3.114e-08
50-150 1.066e-07 5.680e-08
15-150 1.657e-07 8.430e-08
Plot creation:
Thu Sep 25 09:53:20 EDT 2025