batgrbproduct analysis for trigger=1351008
batgrbproduct Analysis for Trigger=1351008
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): Sun Sep 21 11:38:29 EDT 2025
Host Name: batproc1
Current Working Dir: /local/data/bat1/prebascript/trigger1351008/GCN5_download_cron
======================================================================
Trigger: 01351008 Segment: 000
BAT Trigger Time: 780050826.944 [s; MET]
Trigger Stop: 780050827.968 [s; MET]
UTC: 2025-09-20T08:46:30.582840 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 187.336671647084 Dec: 47.8441431180864 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 17.87
Image Trigger?: NO
Rate S/N Ratio: 62.3538290724796 [ if not an image trigger ]
Image S/N Ratio: 17.87
Flight Position: [ source = BAT ]
RA: 187.336671647084 Dec: 47.8441431180864 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 187.315728734299 Dec: 47.8426734415596 [deg; J2000]
{ 12h 29m 15.8s , +47d 50' 33.6" }
+/- 0.716127906467701 [arcmin] (estimated 90% radius based on SNR)
+/- 0.163428806238864 [arcmin] (formal 1-sigma fit error)
SNR: 49.0088677031702
Angular difference between Flight and Ground position is 0.847959 arcmin
Partial Coding Fraction: 0.5703125 [ including projection effects ]
Duration
T90: 128.43599998951 +/- 1.00055178300946
Measured from: -0.263999938964844
to: 128.172000050545 [s; relative to TRIGTIME]
T50: 97.3679999113083 +/- 2.28327480470179
Measured from: 7.4080001115799
to: 104.776000022888 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 0.287999987602234
to: 1.28799998760223 [s; relative to TRIGTIME]
Total Fluence
Measured from: -4.83200001716614
to: 149.432000041008 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 4.602484 6.638463 5.017210 1.300340
0.086567 0.092565 0.080002 0.061270 [error]
Peak 0.131817 0.225880 0.211818 0.059829
0.010872 0.013090 0.012723 0.008888 [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 1.52e-06 2.76e-06 3.84e-06 1.11e-05 1.10e-05 1.92e-05 erg/cm2
Error 6.40e-08 6.65e-08 8.81e-08 6.00e-07 2.20e-07 6.34e-07 erg/cm2
Peak flux Power-law 1.30e+00 1.57e+00 1.36e+00 2.04e+00 4.95e+00 6.27e+00 ph/cm2/s
Error 1.46e-01 1.09e-01 9.80e-02 3.01e-01 3.09e-01 4.13e-01 ph/cm2/s
Fluence Cutoff-PL 1.44e-06 2.78e-06 3.92e-06 8.54e-06 1.09e-05 1.67e-05 erg/cm2
Error 8.63e-08 6.95e-08 1.03e-07 1.54e-06 2.42e-07 1.55e-06 erg/cm2
Peak flux Cutoff-PL 1.20e+00 1.63e+00 1.43e+00 1.32e+00 4.89e+00 5.58e+00 ph/cm2/s
Error 1.76e-01 1.27e-01 1.19e-01 5.68e-01 3.14e-01 6.34e-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 1.525 0.038 - - 7.56e-03 1.48e-04 42.790 57
CPL 1.306 0.154 182.2 153.0 9.42e-03 1.43e-03 36.640 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.199 0.102 - - 4.22e-02 2.59e-03 46.030 57
CPL 0.785 0.420 157.6 448.8 6.68e-02 3.18e-02 42.900 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: 128.000000 sec.
T50 in the 50-300 keV band: 89.984000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 154.264 -4.832 149.432
T90 128.436 -0.264 128.172
T50 97.368 7.408 104.776
Peak 1.000 0.288 1.288
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
187.3157 +47.8427 0.0039 26.4 -72.7 5.0293 49.0 TRIG_01351008
------------------------------------------
Foreground time interval of the image:
-4.832 13.557 (delta_t = 18.389 [sec])
Background time interval of the image:
-239.944 -4.832 (delta_t = 235.112 [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 -4.832 sec. to 149.432 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.52481 ( -0.0377173 0.0377131 )
Norm@50keV : 7.56216E-03 ( -0.000148427 0.000148411 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 42.79 using 59 PHA bins.
# Reduced chi-squared = 0.7507 for 57 degrees of freedom
# Null hypothesis probability = 9.188302e-01
Photon flux (15-150 keV) in 154.3 sec: 0.950499 ( -0.0218991 0.0219844 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.10258e-05 ( -2.1999e-07 2.20089e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -4.832 sec. to 149.432 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.30578 ( -0.156545 0.151432 )
Epeak [keV] : 182.217 ( -52.1711 253.926 )
Norm@50keV : 9.42225E-03 ( -0.00129823 0.00155784 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 36.64 using 59 PHA bins.
# Reduced chi-squared = 0.6542 for 56 degrees of freedom
# Null hypothesis probability = 9.789258e-01
Photon flux (15-150 keV) in 154.3 sec: 0.932313 ( -0.024786 0.024944 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.08863e-05 ( -2.42282e-07 2.41294e-07 ) ergs/cm2
Band function
Time interval is from -4.832 sec. to 149.432 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.31121 ( -0.321337 4.18745 )
beta : -9.36918 ( 9.37152 19.3715 )
Epeak [keV] : 185.690 ( -28.585 117.851 )
Norm@50keV : 9.36909E-03 ( -0.000187045 0.00151474 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 36.64 using 59 PHA bins.
# Reduced chi-squared = 0.6662 for 55 degrees of freedom
# Null hypothesis probability = 9.731656e-01
Photon flux (15-150 keV) in 154.3 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] : 17.6219 ( )
R^2/D10^2 : 5.84364E-02 ( )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 536.42 using 59 PHA bins.
# Reduced chi-squared = 9.4109 for 57 degrees of freedom
# Null hypothesis probability = 3.878535e-79
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 5.643e-07 2.384e-08
25- 50 2.568e-06 7.406e-08
50-150 5.756e-06 1.929e-07
15-150 8.889e-06 1.952e-07
Thermal bremsstrahlung (OTTB)
XSPEC12>exit
XSPEC: quit
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 (-5.72895 -200)
Norm : 3.89103 (-0.0760964 0.0760964)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.495e-06 3.410e-08
25- 50 2.877e-06 6.249e-08
50-150 6.309e-06 1.535e-07
15-150 1.068e-05 2.639e-07
Double BB
XSPEC12>exit
XSPEC: quit
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 7.59047 (-0.597754 0.633613)
R1^2/D10^2 : 0.705343 (-0.170099 0.240162)
kT2 [keV] : 28.1207 (-1.88032 2.30404)
R2^2/D10^2 : 9.24957E-03 (-0.00231376 0.00271868)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.271e-06 9.351e-08
25- 50 2.835e-06 1.018e-07
50-150 6.674e-06 2.739e-07
15-150 1.078e-05 3.611e-07
Peak spectrum fit
Power-law model
Time interval is from 0.288 sec. to 1.288 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.19944 ( -0.101996 0.101756 )
Norm@50keV : 4.21696E-02 ( -0.00259276 0.00259238 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 46.03 using 59 PHA bins.
# Reduced chi-squared = 0.8075 for 57 degrees of freedom
# Null hypothesis probability = 8.505454e-01
Photon flux (15-150 keV) in 1 sec: 4.94946 ( -0.309151 0.309287 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.27896e-07 ( -2.94823e-08 2.95919e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.288 sec. to 1.288 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.785024 ( -0.440392 0.39989 )
Epeak [keV] : 157.619 ( -55.3573 842.167 )
Norm@50keV : 6.67703E-02 ( -0.0232218 0.0403507 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 42.90 using 59 PHA bins.
# Reduced chi-squared = 0.7661 for 56 degrees of freedom
# Null hypothesis probability = 9.007174e-01
Photon flux (15-150 keV) in 1 sec: 4.89196 ( -0.31451 0.31436 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.19434e-07 ( -3.1326e-08 3.1129e-08 ) ergs/cm2
Band function
Time interval is from 0.288 sec. to 1.288 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 3.56195 ( -5.58766 -3.56176 )
beta : -1.31354 ( -0.147129 0.13522 )
Epeak [keV] : 31.1690 ( -6.30588 94.9922 )
Norm@50keV : 109.401 ( -109.249 402.89 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 40.97 using 59 PHA bins.
# Reduced chi-squared = 0.7450 for 55 degrees of freedom
# Null hypothesis probability = 9.202333e-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] : 18.4152 (-1.44158 1.592)
R^2/D10^2 : 0.306284 (-0.0732685 0.0946255)
(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 2.064e-08 2.465e-09
25- 50 9.708e-08 8.260e-09
50-150 2.403e-07 2.740e-08
15-150 3.580e-07 2.960e-08
Thermal bremsstrahlung (OTTB)
XSPEC12>exit
XSPEC: quit
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 (-11.5734 -200)
Norm : 20.2516 (-1.26954 1.26954)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 5.041e-08 3.560e-09
25- 50 9.697e-08 9.230e-09
50-150 2.127e-07 5.470e-08
15-150 3.601e-07 5.990e-08
Double BB
XSPEC12>exit
XSPEC: quit
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 8.28253 (-1.97795 2.53494)
R1^2/D10^2 : 2.33705 (-1.19316 3.0195)
kT2 [keV] : 30.6896 (-6.00527 14.7079)
R2^2/D10^2 : 4.56640E-02 (-0.0326966 0.053129)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.635e-08 1.152e-08
25- 50 9.649e-08 2.215e-08
50-150 2.885e-07 1.056e-07
15-150 4.213e-07 1.210e-07
Plot creation:
Sun Sep 21 11:42:14 EDT 2025