batgrbproduct analysis for trigger=968211
batgrbproduct Analysis for Trigger=968211
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 v2.47
Process Start Time (local time): Tue Apr 28 21:06:08 EDT 2020
Host Name: bat1
Current Working Dir: /local/data/bat1/prebascript/trigger968211/GCN5_download_cron
======================================================================
Trigger: 00968211 Segment: 000
BAT Trigger Time: 609704804.768 [s; MET]
Trigger Stop: 609704805.152 [s; MET]
UTC: 2020-04-27T18:26:19.922940 [includes UTCF correction]
Where From?: (*SHORT BURST*) Expanded to TRIGTIME - 32 ms to TRIGTIME + 320 ms
BAT
RA: 293.735492190112 Dec: 21.8954732560093 [deg; J2000]
Catalogged Source?: YES
Point Source?: YES
GRB Indicated?: NO [ by BAT flight software ]
Image S/N Ratio: 19.26
Image Trigger?: NO
Rate S/N Ratio: 159.543097625689 [ if not an image trigger ]
Image S/N Ratio: 19.26
Flight Position: [ source = BAT ]
RA: 293.735492190112 Dec: 21.8954732560093 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 293.733417498624 Dec: 21.8997364772289 [deg; J2000]
{ 19h 34m 56.0s , +21d 53' 59.1" }
+/- 1.04072064526202 [arcmin] (estimated 90% radius based on SNR)
+/- 0.564253226890923 [arcmin] (formal 1-sigma fit error)
SNR: 28.7313002101717
Angular difference between Flight and Ground position is 0.280661 arcmin
Partial Coding Fraction: 0.8671875 [ including projection effects ]
Duration
T90: 0.0399999618530273 +/- 0.00565678141973815
Measured from: 0.224000096321106
to: 0.264000058174133 [s; relative to TRIGTIME]
T50: 0.0119999647140503 +/- 0.00565678141973815
Measured from: 0.232000112533569
to: 0.24400007724762 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.251999974250793
to: 0.748000025749207 [s; relative to TRIGTIME]
Total Fluence
Measured from: 0.220000028610229
to: 0.271999955177307 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.151179 0.116174 0.023701 0.001066
0.007515 0.006710 0.003277 0.001611 [error]
Peak 0.175636 0.123845 0.035203 -0.004800
0.010867 0.010403 0.007546 0.006091 [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 5.31e-08 3.85e-08 1.85e-08 1.25e-08 1.16e-07 1.23e-07 erg/cm2
Error 4.59e-09 2.93e-09 2.43e-09 2.90e-09 8.49e-09 9.39e-09 erg/cm2
Peak flux Power-law 1.81e+00 9.10e-01 2.81e-01 1.11e-01 3.06e+00 3.11e+00 ph/cm2/s
Error 2.01e-01 9.11e-02 5.39e-02 3.72e-02 2.79e-01 2.84e-01 ph/cm2/s
Fluence Cutoff-PL 4.74e-08 5.25e-08 1.32e-08 3.99e-10 1.13e-07 1.13e-07 erg/cm2
Error 5.18e-09 4.64e-09 3.43e-09 5.31e-10 8.24e-09 8.24e-09 erg/cm2
Peak flux Cutoff-PL 1.72e+00 1.10e+00 1.46e-01 2.16e-03 2.98e+00 2.98e+00 ph/cm2/s
Error 2.19e-01 1.30e-01 8.67e-02 8.82e-03 2.80e-01 2.80e-01 ph/cm2/s
Fluence Band -------- -------- -------- -------- -------- -------- erg/cm2
Error -------- -------- -------- -------- -------- -------- erg/cm2
Peak flux Band 1.73e+00 1.07e+00 1.95e-01 4.08e-02 3.02e+00 3.04e+00 ph/cm2/s
Error 2.32e-01 1.18e-01 7.00e-02 3.28e-02 2.84e-01 2.88e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 3.058 0.124 - - 1.81e-01 1.85e-02 95.390 57
CPL 1.000 0.000 50.0 0.0 5.91e-01 0.00e+00 288.900 56
The chi2 of BB fit is 56.27 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 2.693 0.184 - - 1.38e-02 2.05e-03 70.670 57
CPL 0.155 1.711 22.8 6.4 7.21e-01 1.12e+01 56.100 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: 0.000000 sec.
T50 in the 50-300 keV band: 0.000000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 0.052 0.220 0.272
T90 0.040 0.224 0.264
T50 0.012 0.232 0.244
Peak 1.000 -0.252 0.748
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
293.7334 +21.8997 0.0067 28.2 1.5 0.3013 28.7 TRIG_00968211
------------------------------------------
Foreground time interval of the image:
0.220 0.272 (delta_t = 0.052 [sec])
Background time interval of the image:
-239.768 0.220 (delta_t = 239.988 [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 0.220 sec. to 0.272 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 3.05804 ( -0.121122 0.127432 )
Norm@50keV : 0.180636 ( -0.018534 0.018393 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 95.39 using 59 PHA bins.
# Reduced chi-squared = 1.674 for 57 degrees of freedom
# Null hypothesis probability = 1.083868e-03
Photon flux (15-150 keV) in 0.052 sec: 51.8361 ( -3.85968 3.86307 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.15974e-07 ( -8.48676e-09 8.49545e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.220 sec. to 0.272 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.00000 ( )
Epeak [keV] : 50.0000 ( )
Norm@50keV : 0.590673 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 288.90 using 59 PHA bins.
# Reduced chi-squared = 5.1589 for 56 degrees of freedom
# Null hypothesis probability = 4.278148e-33
Photon flux (15-150 keV) in 0.052 sec: 50.9928 ( -3.9183 3.9212 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.13429e-07 ( 0 0 ) ergs/cm2
Band function
Time interval is from 0.220 sec. to 0.272 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.27808E-02 ( -0.901463 1.66671 )
beta : -5.44104 ( 5.47913 1.46802 )
Epeak [keV] : 23.1899 ( -4.03698 2.25328 )
Norm@50keV : 15.5854 ( -14.439 217.586 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 46.68 using 59 PHA bins.
# Reduced chi-squared = 0.8487 for 55 degrees of freedom
# Null hypothesis probability = 7.803020e-01
Photon flux (15-150 keV) in 0.052 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] : 6.88308 (-0.419142 0.434359)
R^2/D10^2 : 109.073 (-26.9516 36.4828)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.27 using 59 PHA bins.
# Reduced chi-squared = 0.9872 for 57 degrees of freedom
# Null hypothesis probability = 5.024787e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.241e-08 4.373e-09
25- 50 5.620e-08 4.472e-09
50-150 8.759e-09 1.945e-09
15-150 1.074e-07 7.566e-09
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 22.1340 (-2.17566 2.3962)
Norm : 582.031 (-80.0461 93.2273)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.05 using 59 PHA bins.
# Reduced chi-squared = 0.9306 for 57 degrees of freedom
# Null hypothesis probability = 6.241457e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 5.090e-08 4.285e-09
25- 50 4.805e-08 3.494e-09
50-150 1.698e-08 3.442e-09
15-150 1.159e-07 8.346e-09
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 4.84868 (-1.87051 1.59568)
R1^2/D10^2 : 295.791 (-162.274 1388.45)
kT2 [keV] : 9.22644 (-1.78994 8.33826)
R2^2/D10^2 : 16.6111 (-16.3453 51.2331)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 46.82 using 59 PHA bins.
# Reduced chi-squared = 0.8513 for 55 degrees of freedom
# Null hypothesis probability = 7.757097e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.752e-08 2.443e-08
25- 50 5.199e-08 2.631e-08
50-150 1.387e-08 7.761e-09
15-150 1.134e-07 5.234e-08
Peak spectrum fit
Power-law model
Time interval is from -0.252 sec. to 0.748 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.69314 ( -0.178327 0.190534 )
Norm@50keV : 1.37919E-02 ( -0.00204319 0.00204849 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 70.67 using 59 PHA bins.
# Reduced chi-squared = 1.240 for 57 degrees of freedom
# Null hypothesis probability = 1.053640e-01
Photon flux (15-150 keV) in 1 sec: 3.06417 ( -0.279382 0.279406 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.46373e-07 ( -1.53344e-08 1.56077e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.252 sec. to 0.748 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.155334 ( -2.07445 1.34788 )
Epeak [keV] : 22.8197 ( -9.21083 3.64492 )
Norm@50keV : 0.721033 ( -0.777572 21.6685 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.10 using 59 PHA bins.
# Reduced chi-squared = 1.002 for 56 degrees of freedom
# Null hypothesis probability = 4.710185e-01
Photon flux (15-150 keV) in 1 sec: 2.97522 ( -0.27968 0.27987 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.26934e-07 ( -1.4095e-08 1.5364e-08 ) ergs/cm2
Band function
Time interval is from -0.252 sec. to 0.748 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 4.40858 ( -4.40267 -4.40858 )
beta : -3.45250 ( -0.554062 0.390551 )
Epeak [keV] : 23.2286 ( -1.85836 1.90711 )
Norm@50keV : 2539.06 ( -224.529 12565.9 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.70 using 59 PHA bins.
# Reduced chi-squared = 0.9218 for 55 degrees of freedom
# Null hypothesis probability = 6.395481e-01
Photon flux (15-150 keV) in 1 sec: 3.02417 ( 3.97583 -0.28424 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.26763e-07 ( 0 0 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 6.42588 (-0.52683 0.576571)
R^2/D10^2 : 8.64671 (-2.74304 4.0026)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.61 using 59 PHA bins.
# Reduced chi-squared = 1.028 for 57 degrees of freedom
# Null hypothesis probability = 4.159972e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 5.202e-08 7.300e-09
25- 50 6.001e-08 8.245e-09
50-150 7.220e-09 2.575e-09
15-150 1.192e-07 1.300e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 25.0150 (-4.13602 5.19735)
Norm : 29.6858 (-5.52006 6.94878)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.14 using 59 PHA bins.
# Reduced chi-squared = 1.020 for 57 degrees of freedom
# Null hypothesis probability = 4.330347e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 5.439e-08 6.290e-09
25- 50 5.577e-08 6.520e-09
50-150 2.374e-08 7.570e-09
15-150 1.339e-07 1.475e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 5.56520 (-0.914801 0.766993)
R1^2/D10^2 : 14.0464 (-5.28521 10.5915)
kT2 [keV] : 15.8001 (-6.93705 17.2228)
R2^2/D10^2 : 5.57264E-02 (-0.0449325 0.587437)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.28 using 59 PHA bins.
# Reduced chi-squared = 0.9325 for 55 degrees of freedom
# Null hypothesis probability = 6.173522e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 5.435e-08 1.953e-08
25- 50 5.538e-08 2.070e-08
50-150 2.374e-08 1.515e-08
15-150 1.335e-07 4.519e-08
Plot creation:
Tue Apr 28 21:08:00 EDT 2020