batgrbproduct analysis for trigger=1108538
batgrbproduct Analysis for Trigger=1108538
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): Tue May 31 20:14:18 EDT 2022
Host Name: batproc1
Current Working Dir: /local/data/bat1/prebascript/trigger1108538/GCN5_download_cron
======================================================================
Trigger: 01108538 Segment: 000
BAT Trigger Time: 675635575.88 [s; MET]
Trigger Stop: 675635575.896 [s; MET]
UTC: 2022-05-30T20:32:26.647840 [includes UTCF correction]
Where From?: (*SHORT BURST*) TDRSS scaled map message
BAT
RA: 293.71420400356 Dec: 21.9012441525763 [deg; J2000]
Catalogged Source?: YES
Point Source?: YES
GRB Indicated?: NO [ by BAT flight software ]
Image S/N Ratio: 22.93
Image Trigger?: NO
Rate S/N Ratio: 255.998046867549 [ if not an image trigger ]
Image S/N Ratio: 22.93
Flight Position: [ source = BAT ]
RA: 293.71420400356 Dec: 21.9012441525763 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 293.726411300169 Dec: 21.8916599275078 [deg; J2000]
{ 19h 34m 54.3s , +21d 53' 30.0" }
+/- 0.625203837765301 [arcmin] (estimated 90% radius based on SNR)
+/- 0.214463436486806 [arcmin] (formal 1-sigma fit error)
SNR: 59.4998737104746
Angular difference between Flight and Ground position is 0.890248 arcmin
Partial Coding Fraction: 0.8671875 [ including projection effects ]
Duration
T90: 0.111999988555908 +/- 0.0164924703816713
Measured from: -0.0839998722076416
to: 0.0280001163482666 [s; relative to TRIGTIME]
T50: 0.0359998941421509 +/- 0.004
Measured from: -0.0279998779296875
to: 0.00800001621246338 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.526000022888184
to: 0.473999977111816 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.167999982833862
to: 0.111999988555908 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.845583 0.822847 0.196373 0.003085
0.017362 0.016968 0.008734 0.003281 [error]
Peak 0.852716 0.834007 0.192506 0.005214
0.018441 0.018081 0.010333 0.005681 [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 3.56e-07 2.62e-07 1.28e-07 8.91e-08 7.88e-07 8.35e-07 erg/cm2
Error -------- -------- -------- -------- -------- -------- erg/cm2
Peak flux Power-law 1.09e+01 5.31e+00 1.59e+00 6.01e-01 1.81e+01 1.84e+01 ph/cm2/s
Error -------- -------- -------- -------- -------- -------- ph/cm2/s
Fluence Cutoff-PL 2.52e-07 3.51e-07 1.43e-07 1.06e-08 7.56e-07 7.56e-07 erg/cm2
Error 1.81e-08 1.27e-08 1.02e-08 3.33e-09 2.68e-08 2.70e-08 erg/cm2
Peak flux Cutoff-PL 8.18e+00 6.51e+00 1.41e+00 5.48e-02 1.62e+01 1.62e+01 ph/cm2/s
Error 6.52e-01 2.55e-01 1.18e-01 2.31e-02 7.36e-01 7.37e-01 ph/cm2/s
Fluence Band 2.53e-07 3.47e-07 1.44e-07 1.17e-08 7.58e-07 7.59e-07 erg/cm2
Error 1.50e-08 1.19e-08 9.81e-09 -------- 2.60e-08 -------- 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 3.032 0.000 - - 2.31e-01 0.00e+00 415.510 57
CPL 0.265 0.355 28.1 2.1 7.62e+00 3.71e+00 64.600 56
The chi2 of BB fit is 119.79 which shows a significant improvement in the fit over a PL.
Check the BB fit.
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.742 0.000 - - 7.89e-02 0.00e+00 207.610 57
CPL 0.226 0.444 28.1 2.3 2.29e+00 1.49e+00 50.930 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: 0.064000 sec.
T50 in the 50-300 keV band: 0.064000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 0.280 -0.168 0.112
T90 0.112 -0.084 0.028
T50 0.036 -0.028 0.008
Peak 1.000 -0.526 0.474
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
293.7264 +21.8917 0.0032 17.5 -122.6 1.9494 59.5 TRIG_01108538
------------------------------------------
Foreground time interval of the image:
-0.168 0.112 (delta_t = 0.280 [sec])
Background time interval of the image:
-239.880 -0.168 (delta_t = 239.712 [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 -0.168 sec. to 0.112 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 3.03151 ( )
Norm@50keV : 0.230721 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 415.51 using 59 PHA bins.
# Reduced chi-squared = 7.2897 for 57 degrees of freedom
# Null hypothesis probability = 6.433482e-56
Photon flux (15-150 keV) in 0.28 sec: 64.9215 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 7.87646e-07 ( 0 0 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.168 sec. to 0.112 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.264933 ( -0.371015 0.338554 )
Epeak [keV] : 28.0666 ( -2.27126 1.93081 )
Norm@50keV : 7.61603 ( -2.69169 4.72576 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.60 using 59 PHA bins.
# Reduced chi-squared = 1.153 for 56 degrees of freedom
# Null hypothesis probability = 2.015053e-01
Photon flux (15-150 keV) in 0.28 sec: 57.1298 ( -2.472 2.4906 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.55527e-07 ( 0 0 ) ergs/cm2
Band function
Time interval is from -0.168 sec. to 0.112 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.265259 ( -0.340459 0.348059 )
beta : -10.0000 ( 10 10 )
Epeak [keV] : 28.0576 ( -2.2677 1.93193 )
Norm@50keV : 7.61515 ( -2.6847 4.74119 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.60 using 59 PHA bins.
# Reduced chi-squared = 1.175 for 55 degrees of freedom
# Null hypothesis probability = 1.762389e-01
Photon flux (15-150 keV) in 0.28 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 7.58162e-07 ( 0 0 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 8.49046 ( )
R^2/D10^2 : 51.0526 ( )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 119.79 using 59 PHA bins.
# Reduced chi-squared = 2.1017 for 57 degrees of freedom
# Null hypothesis probability = 2.310352e-06
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.941e-07 1.149e-08
25- 50 3.756e-07 1.176e-08
50-150 1.195e-07 9.450e-09
15-150 6.892e-07 2.268e-08
Thermal bremsstrahlung (OTTB)
XSPEC12>exit
XSPEC: quit
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 28.1993 (-1.26545 1.3044)
Norm : 539.023 (-33.2339 35.7559)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.972e-07 1.330e-08
25- 50 3.279e-07 9.800e-09
50-150 1.653e-07 1.113e-08
15-150 7.904e-07 2.506e-08
Double BB
XSPEC12>exit
XSPEC: quit
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 5.79751 (-0.774885 0.708384)
R1^2/D10^2 : 158.580 (-49.0244 95.5914)
kT2 [keV] : 11.6948 (-1.1074 1.33733)
R2^2/D10^2 : 7.13716 (-3.66011 6.34735)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.461e-07 3.171e-08
25- 50 3.502e-07 5.072e-08
50-150 1.560e-07 4.119e-08
15-150 7.523e-07 1.072e-07
Peak spectrum fit
Power-law model
Time interval is from -0.526 sec. to 0.474 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.74214 ( )
Norm@50keV : 7.89489E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 207.61 using 59 PHA bins.
# Reduced chi-squared = 3.6422 for 57 degrees of freedom
# Null hypothesis probability = 5.468981e-19
Photon flux (15-150 keV) in 1 sec: 18.1229 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 8.5262e-07 ( 0 0 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.526 sec. to 0.474 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.225512 ( -0.462662 0.425614 )
Epeak [keV] : 28.1346 ( -2.52436 2.02052 )
Norm@50keV : 2.29063 ( -0.995628 1.98664 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.93 using 59 PHA bins.
# Reduced chi-squared = 0.9095 for 56 degrees of freedom
# Null hypothesis probability = 6.665621e-01
Photon flux (15-150 keV) in 1 sec: 16.1577 ( -0.7339 0.7386 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.62122e-07 ( -2.9861e-08 3.0103e-08 ) ergs/cm2
Band function
Time interval is from -0.526 sec. to 0.474 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 7.28724E-02 ( -0.534684 0.680955 )
beta : -4.40352 ( 4.40293 0.545713 )
Epeak [keV] : 28.6788 ( -2.27219 1.7922 )
Norm@50keV : 3.56885 ( -1.90323 6.02767 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.08 using 59 PHA bins.
# Reduced chi-squared = 0.8924 for 55 degrees of freedom
# Null hypothesis probability = 6.990326e-01
Photon flux (15-150 keV) in 1 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 7.68438e-07 ( -7.68431e-07 -3.0421e-08 ) ergs/cm2
Single BB
XSPEC: quit
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 8.32434 (-0.246244 0.251967)
R^2/D10^2 : 15.7569 (-2.0038 2.30323)
(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 2.030e-07 1.175e-08
25- 50 3.803e-07 1.280e-08
50-150 1.136e-07 1.045e-08
15-150 6.969e-07 2.270e-08
Thermal bremsstrahlung (OTTB)
XSPEC12>exit
XSPEC: quit
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 29.8477 (-1.68267 1.8112)
Norm : 143.571 (-10.1232 10.8824)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.914e-07 1.375e-08
25- 50 3.321e-07 1.100e-08
50-150 1.806e-07 1.520e-08
15-150 8.042e-07 2.715e-08
Double BB
XSPEC12>exit
XSPEC: quit
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 6.18895 (-1.21828 0.925514)
R1^2/D10^2 : 37.5783 (-12.0182 31.5132)
kT2 [keV] : 12.3666 (-2.14937 3.9379)
R2^2/D10^2 : 1.36492 (-1.10475 3.24122)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.439e-07 3.705e-08
25- 50 3.570e-07 5.530e-08
50-150 1.573e-07 6.104e-08
15-150 7.583e-07 1.363e-07
Plot creation:
Tue May 31 20:17:26 EDT 2022