batgrbproduct analysis for trigger=1308754
batgrbproduct Analysis for Trigger=1308754
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): Fri May 2 05:12:08 EDT 2025
Host Name: batproc1
Current Working Dir: /local/data/bat1/prebascript/trigger1308754/GCN5_download_cron
======================================================================
Trigger: 01308754 Segment: 000
BAT Trigger Time: 767727095.808 [s; MET]
Trigger Stop: 767727096.832 [s; MET]
UTC: 2025-04-30T17:31:00.286940 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 233.428106944477 Dec: -18.0833375040458 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 13.49
Image Trigger?: NO
Rate S/N Ratio: 32.2490309931942 [ if not an image trigger ]
Image S/N Ratio: 13.49
Flight Position: [ source = BAT ]
RA: 233.428106944477 Dec: -18.0833375040458 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 233.394762247466 Dec: -18.1008873451324 [deg; J2000]
{ 15h 33m 34.7s , -18d 06' 03.2" }
+/- 1.05711450756152 [arcmin] (estimated 90% radius based on SNR)
+/- 0.424855407581883 [arcmin] (formal 1-sigma fit error)
SNR: 28.0968952809152
Angular difference between Flight and Ground position is 2.173821 arcmin
Partial Coding Fraction: 0.7265625 [ including projection effects ]
Duration
T90: 9.17199993133545 +/- 1.70176374998516
Measured from: 0.420000195503235
to: 9.59200012683868 [s; relative to TRIGTIME]
T50: 4.3439998626709 +/- 0.437611692826095
Measured from: 1.54000020027161
to: 5.8840000629425 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 0.308000087738037
to: 1.30800008773804 [s; relative to TRIGTIME]
Total Fluence
Measured from: 0.096000075340271
to: 11.8600000143051 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.447317 0.587889 0.384145 0.084279
0.030155 0.028417 0.023410 0.017923 [error]
Peak 0.063683 0.110078 0.086339 0.028185
0.009185 0.009294 0.008336 0.006384 [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 1.42e-07 2.37e-07 3.01e-07 7.66e-07 8.93e-07 1.45e-06 erg/cm2
Error 1.43e-08 1.42e-08 2.36e-08 1.30e-07 5.58e-08 1.47e-07 erg/cm2
Peak flux Power-law 6.54e-01 7.39e-01 5.97e-01 8.03e-01 2.28e+00 2.79e+00 ph/cm2/s
Error 1.15e-01 7.97e-02 6.73e-02 1.89e-01 2.23e-01 2.74e-01 ph/cm2/s
Fluence Cutoff-PL 1.37e-07 2.42e-07 3.05e-07 5.45e-07 8.77e-07 1.23e-06 erg/cm2
Error 1.72e-08 1.69e-08 2.49e-08 3.45e-07 6.31e-08 2.59e-07 erg/cm2
Peak flux Cutoff-PL 5.74e-01 7.75e-01 6.31e-01 4.21e-01 2.22e+00 2.40e+00 ph/cm2/s
Error 1.39e-01 9.28e-02 7.86e-02 3.03e-01 2.34e-01 3.93e-01 ph/cm2/s
Fluence Band 1.30e-07 2.47e-07 2.98e-07 6.71e-07 8.75e-07 1.35e-06 erg/cm2
Error -------- -------- 2.45e-08 -------- -------- -------- erg/cm2
Peak flux Band 5.14e-01 8.24e-01 6.04e-01 5.99e-01 2.19e+00 2.54e+00 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 1.655 0.106 - - 8.17e-03 4.81e-04 54.520 57
CPL 1.434 0.357 127.1 0.0 1.06e-02 0.00e+00 53.650 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.308 0.164 - - 1.91e-02 1.81e-03 65.480 57
CPL 0.676 0.717 109.4 -36.7 3.87e-02 3.70e-02 62.870 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: 6.400000 sec.
T50 in the 50-300 keV band: 3.904000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 11.764 0.096 11.860
T90 9.172 0.420 9.592
T50 4.344 1.540 5.884
Peak 1.000 0.308 1.308
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
233.3948 -18.1009 0.0068 22.0 135.4 1.6249 28.1 TRIG_01308754
------------------------------------------
Foreground time interval of the image:
0.096 11.860 (delta_t = 11.764 [sec])
Background time interval of the image:
-60.808 0.096 (delta_t = 60.904 [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 0.096 sec. to 11.860 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.65526 ( -0.105068 0.106015 )
Norm@50keV : 8.16980E-03 ( -0.000481979 0.000480032 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.52 using 59 PHA bins.
# Reduced chi-squared = 0.9565 for 57 degrees of freedom
# Null hypothesis probability = 5.685744e-01
Photon flux (15-150 keV) in 11.76 sec: 1.06863 ( -0.0638186 0.0639905 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.93085e-07 ( -5.56219e-08 5.59133e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.096 sec. to 11.860 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.43359 ( -0.437783 0.276263 )
Epeak [keV] : 127.131 ( )
Norm@50keV : 1.05665E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.65 using 59 PHA bins.
# Reduced chi-squared = 0.9581 for 56 degrees of freedom
# Null hypothesis probability = 5.642744e-01
Photon flux (15-150 keV) in 11.76 sec: 1.05454 ( -0.068449 0.06855 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.77312e-07 ( -6.3357e-08 6.28537e-08 ) ergs/cm2
Band function
Time interval is from 0.096 sec. to 11.860 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.820017 ( 0.96643 5.54248 )
beta : -1.76985 ( -0.266352 0.166887 )
Epeak [keV] : 51.4186 ( -50.7097 -50.7097 )
Norm@50keV : 2.60648E-02 ( -0.0276865 922088 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.70 using 59 PHA bins.
# Reduced chi-squared = 0.9582 for 55 degrees of freedom
# Null hypothesis probability = 5.629813e-01
Photon flux (15-150 keV) in 11.76 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 8.75312e-07 ( 0 0 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 13.6014 ( )
R^2/D10^2 : 0.161336 ( )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 123.31 using 59 PHA bins.
# Reduced chi-squared = 2.1633 for 57 degrees of freedom
# Null hypothesis probability = 8.641495e-07
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 7.431e-08 8.679e-09
25- 50 2.684e-07 2.017e-08
50-150 3.220e-07 4.157e-08
15-150 6.648e-07 4.592e-08
Thermal bremsstrahlung (OTTB)
XSPEC12>exit
XSPEC: quit
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 155.986 (-38.5757 -155.799)
Norm : 4.36548 (-0.292548 0.339342)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.314e-07 1.076e-08
25- 50 2.449e-07 2.634e-08
50-150 4.912e-07 1.689e-07
15-150 8.676e-07 2.233e-07
Double BB
XSPEC12>exit
XSPEC: quit
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 7.74234 (-1.25912 1.31835)
R1^2/D10^2 : 0.873790 (-0.347353 0.702581)
kT2 [keV] : 28.9998 (-6.03521 11.4603)
R2^2/D10^2 : 7.93398E-03 (-0.00528316 0.0108584)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.211e-07 2.129e-08
25- 50 2.556e-07 4.369e-08
50-150 5.007e-07 1.819e-07
15-150 8.774e-07 2.320e-07
Peak spectrum fit
Power-law model
Time interval is from 0.308 sec. to 1.308 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.30795 ( -0.164045 0.163452 )
Norm@50keV : 1.91154E-02 ( -0.00181553 0.00181388 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 65.48 using 59 PHA bins.
# Reduced chi-squared = 1.149 for 57 degrees of freedom
# Null hypothesis probability = 2.061647e-01
Photon flux (15-150 keV) in 1 sec: 2.28381 ( -0.222532 0.223172 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.88531e-07 ( -1.97691e-08 1.99253e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.308 sec. to 1.308 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.676457 ( -0.794929 0.639254 )
Epeak [keV] : 109.413 ( -35.9313 -109.412 )
Norm@50keV : 3.87121E-02 ( -0.0199068 0.0540143 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.87 using 59 PHA bins.
# Reduced chi-squared = 1.123 for 56 degrees of freedom
# Null hypothesis probability = 2.461893e-01
Photon flux (15-150 keV) in 1 sec: 2.21835 ( -0.23366 0.23347 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.8038e-07 ( -2.2275e-08 2.1997e-08 ) ergs/cm2
Band function
Time interval is from 0.308 sec. to 1.308 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.331950 ( -1.59168 3.09085 )
beta : -1.63157 ( 1.63017 0.330279 )
Epeak [keV] : 58.7222 ( -25.5577 170.957 )
Norm@50keV : 0.156901 ( -0.160944 92.3701 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.56 using 59 PHA bins.
# Reduced chi-squared = 1.119 for 55 degrees of freedom
# Null hypothesis probability = 2.528336e-01
Photon flux (15-150 keV) in 1 sec: 2.18943 ( ) 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] : 16.5047 (-1.92713 2.28962)
R^2/D10^2 : 0.194803 (-0.0697987 0.103773)
(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 1.089e-08 2.043e-09
25- 50 4.705e-08 5.955e-09
50-150 9.060e-08 1.703e-08
15-150 1.485e-07 1.895e-08
Thermal bremsstrahlung (OTTB)
XSPEC12>exit
XSPEC: quit
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 (-33.3368 -200)
Norm : 9.48810 (-0.90478 0.90478)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.363e-08 1.238e-08
25- 50 4.546e-08 1.882e-08
50-150 9.970e-08 5.158e-08
15-150 1.688e-07 8.938e-08
Double BB
XSPEC12>exit
XSPEC: quit
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 10.3121 (-2.954 3.00522)
R1^2/D10^2 : 0.651162 (-0.328052 0.526123)
kT2 [keV] : 37.2663 (-13.9028 -37.3447)
R2^2/D10^2 : 8.81945E-03 (-0.0086126 0.0379862)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.590e-08 6.823e-09
25- 50 4.804e-08 2.418e-08
50-150 1.179e-07 6.011e-08
15-150 1.819e-07 8.339e-08
Plot creation:
Fri May 2 05:14:37 EDT 2025