batgrbproduct analysis for trigger=1420873
batgrbproduct Analysis for Trigger=1420873
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 Dec 6 19:32:19 EST 2025
Host Name: batproc1
Current Working Dir: /local/data/bat1/prebascript/trigger1420873/GCN5_download_cron
======================================================================
Trigger: 01420873 Segment: 000
BAT Trigger Time: 786670824.064 [s; MET]
Trigger Stop: 786670836.224 [s; MET]
UTC: 2025-12-05T23:39:47.254040 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 200.243464502567 Dec: 29.9625366465604 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.81
Image Trigger?: NO
Rate S/N Ratio: 10 [ if not an image trigger ]
Image S/N Ratio: 7.81
Flight Position: [ source = BAT ]
RA: 200.243464502567 Dec: 29.9625366465604 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 200.260233007476 Dec: 29.9058964509097 [deg; J2000]
{ 13h 21m 02.5s , +29d 54' 21.2" }
+/- 2.08719871635066 [arcmin] (estimated 90% radius based on SNR)
+/- 0.885353540297219 [arcmin] (formal 1-sigma fit error)
SNR: 10.6316009462183
Angular difference between Flight and Ground position is 3.508476 arcmin
Partial Coding Fraction: 0.453125 [ including projection effects ]
Duration
T90: 128 +/- 65.9696900098826
Measured from: 0.936000108718872
to: 128.936000108719 [s; relative to TRIGTIME]
T50: 32 +/- 32
Measured from: 0.936000108718872
to: 32.9360001087189 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 8.43599998950958
to: 9.43599998950958 [s; relative to TRIGTIME]
Total Fluence
Measured from: 0.935999989509583
to: 144.93599998951 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.559991 0.671994 0.425748 0.028886
0.091997 0.094835 0.079599 0.065461 [error]
Peak 0.022062 0.022499 0.024220 0.005049
0.009060 0.009217 0.007904 0.006662 [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 1.71e-07 2.83e-07 3.57e-07 8.99e-07 1.06e-06 1.71e-06 erg/cm2
Error 4.03e-08 4.25e-08 7.85e-08 4.14e-07 1.85e-07 4.83e-07 erg/cm2
Peak flux Power-law 1.83e-01 1.81e-01 1.25e-01 1.36e-01 5.43e-01 6.25e-01 ph/cm2/s
Error 1.22e-01 7.52e-02 9.40e-02 1.70e-01 2.14e-01 2.47e-01 ph/cm2/s
Fluence Cutoff-PL 1.69e-07 2.86e-07 3.59e-07 7.40e-07 1.06e-06 1.50e-06 erg/cm2
Error 3.31e-08 4.92e-08 8.08e-08 5.31e-07 1.93e-07 6.30e-07 erg/cm2
Peak flux Cutoff-PL 1.87e-01 1.81e-01 1.23e-01 1.31e-01 5.44e-01 6.24e-01 ph/cm2/s
Error 1.30e-01 7.95e-02 6.84e-02 1.29e-01 2.14e-01 2.54e-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 1.666 0.270 - - 7.94e-04 1.29e-04 49.990 57
CPL 1.640 1.256 676.3 -0.0 8.20e-04 1.18e-03 49.990 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.532 0.780 - - 4.31e-03 1.79e-03 49.960 57
CPL 3.835 2.766 441.0 0.0 3.45e-04 0.00e+00 49.790 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: 14.336000 sec.
T50 in the 50-300 keV band: 8.448000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 144.000 0.936 144.936
T90 128.000 0.936 128.936
T50 32.000 0.936 32.936
Peak 1.000 8.436 9.436
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
200.2602 +29.9059 0.0181 26.0 98.9 1.4835 10.6 TRIG_01420873
------------------------------------------
Foreground time interval of the image:
0.936 63.437 (delta_t = 62.501 [sec])
Background time interval of the image:
-239.064 -182.594 (delta_t = 56.470 [sec])
-181.064 0.936 (delta_t = 182.000 [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 0.936 sec. to 144.936 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.66581 ( -0.264638 0.275413 )
Norm@50keV : 7.94460E-04 ( -0.000130904 0.000127792 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.99 using 59 PHA bins.
# Reduced chi-squared = 0.8770 for 57 degrees of freedom
# Null hypothesis probability = 7.331643e-01
Photon flux (15-150 keV) in 144 sec: 0.104284 ( -0.0156249 0.0156415 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.06235e-06 ( -1.83224e-07 1.86394e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.936 sec. to 144.936 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.64043 ( -1.08642 1.42592 )
Epeak [keV] : 676.333 ( -676.288 -676.298 )
Norm@50keV : 8.19577E-04 ( -0.000155279 0.00219986 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.99 using 59 PHA bins.
# Reduced chi-squared = 0.8926 for 56 degrees of freedom
# Null hypothesis probability = 7.006131e-01
Photon flux (15-150 keV) in 144 sec: 0.104058 ( -0.0159328 0.015824 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.05736e-06 ( -1.9588e-07 1.90354e-07 ) ergs/cm2
Band function
Time interval is from 0.936 sec. to 144.936 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -7.40309 ( 6.17585 7.40309 )
beta : -1.66582 ( -0.275406 0.264638 )
Epeak [keV] : 138.373 ( -138.373 -138.373 )
Norm@50keV : 0.107978 ( -0.0177917 0.017369 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.99 using 59 PHA bins.
# Reduced chi-squared = 0.9089 for 55 degrees of freedom
# Null hypothesis probability = 6.659982e-01
Photon flux (15-150 keV) in 144 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] : 12.9247 (-2.35682 3.02975)
R^2/D10^2 : 1.92617E-02 (-0.0102576 0.0207286)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 63.53 using 59 PHA bins.
# Reduced chi-squared = 1.115 for 57 degrees of freedom
# Null hypothesis probability = 2.572584e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 9.827e-08 2.980e-08
25- 50 3.364e-07 7.207e-08
50-150 3.540e-07 1.161e-07
15-150 7.886e-07 1.796e-07
Thermal bremsstrahlung (OTTB)
XSPEC12>exit
XSPEC: quit
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 160.038 (-80.1612 -158.149)
Norm : 0.425885 (-0.0673889 0.0951961)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.566e-07 8.654e-08
25- 50 2.929e-07 1.613e-07
50-150 5.935e-07 3.454e-07
15-150 1.043e-06 5.861e-07
Double BB
XSPEC12>exit
XSPEC: quit
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 5.04312 (-2.63355 4.9982)
R1^2/D10^2 : 0.387756 (-0.329539 13.1722)
kT2 [keV] : 21.1502 (-7.15852 52.8226)
R2^2/D10^2 : 2.73425E-03 (-0.00251589 0.00336565)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.737e-07 9.684e-08
25- 50 2.650e-07 1.235e-07
50-150 5.753e-07 3.421e-07
15-150 1.014e-06 4.741e-07
Peak spectrum fit
Power-law model
Time interval is from 8.436 sec. to 9.436 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.53179 ( -0.744193 0.81536 )
Norm@50keV : 4.30975E-03 ( -0.0018496 0.00172185 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.96 using 59 PHA bins.
# Reduced chi-squared = 0.8765 for 57 degrees of freedom
# Null hypothesis probability = 7.340684e-01
Photon flux (15-150 keV) in 1 sec: 0.542741 ( -0.213578 0.214137 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.06805e-08 ( -1.78662e-08 1.83685e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 8.436 sec. to 9.436 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 3.83548 ( -5.04875 0.482995 )
Epeak [keV] : 441.003 ( )
Norm@50keV : 3.44611E-04 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.79 using 59 PHA bins.
# Reduced chi-squared = 0.8890 for 56 degrees of freedom
# Null hypothesis probability = 7.077297e-01
Photon flux (15-150 keV) in 1 sec: 0.543614 ( -0.215401 0.213188 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.03912e-08 ( -1.76707e-08 1.85404e-08 ) ergs/cm2
Band function
Time interval is from 8.436 sec. to 9.436 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.32681 ( 1.32893 1.32893 )
beta : -1.52261 ( 1.5317 0.743387 )
Epeak [keV] : 32.6905 ( -33.5043 -33.5043 )
Norm@50keV : 7.22664E-03 ( -0.00464423 80.7418 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.96 using 59 PHA bins.
# Reduced chi-squared = 0.9084 for 55 degrees of freedom
# Null hypothesis probability = 6.669567e-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] : 17.1527 (-8.33525 16.7912)
R^2/D10^2 : 3.74139E-02 (-0.0367484 0.334585)
(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 2.236e-09 1.548e-09
25- 50 9.965e-09 6.385e-09
50-150 2.099e-08 1.480e-08
15-150 3.319e-08 2.255e-08
Thermal bremsstrahlung (OTTB)
XSPEC12>exit
XSPEC: quit
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 199.361 (-199.362 -199.362)
Norm : 2.20944 (-0.85682 1.23823)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 5.502e-09 3.575e-09
25- 50 1.058e-08 6.785e-09
50-150 2.321e-08 1.497e-08
15-150 3.930e-08 2.465e-08
Double BB
XSPEC12>exit
XSPEC: quit
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 3.30614 (-3.13604 12.0331)
R1^2/D10^2 : 15.5246 (-15.2879 -15.3273)
kT2 [keV] : 23.2506 (-11.3262 -23.269)
R2^2/D10^2 : 1.22916E-02 (-0.012118 0.107678)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 6.376e-09 3.498e-09
25- 50 7.585e-09 4.433e-09
50-150 2.639e-08 1.848e-08
15-150 4.035e-08 2.316e-08
Plot creation:
Sat Dec 6 19:36:07 EST 2025