batgrbproduct analysis for trigger=968731
batgrbproduct Analysis for Trigger=968731
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): Fri May 1 19:20:23 EDT 2020
Host Name: bat1
Current Working Dir: /local/data/bat1/prebascript/trigger968731/GCN5_download_cron
======================================================================
Trigger: 00968731 Segment: 000
BAT Trigger Time: 609944226.836 [s; MET]
Trigger Stop: 609944226.868 [s; MET]
UTC: 2020-04-30T12:56:41.975400 [includes UTCF correction]
Where From?: (*SHORT BURST*) TDRSS scaled map message
BAT
RA: 272.131488929659 Dec: -20.3976033897298 [deg; J2000]
Catalogged Source?: YES
Point Source?: YES
GRB Indicated?: NO [ by BAT flight software ]
Image S/N Ratio: 8.92
Image Trigger?: NO
Rate S/N Ratio: 20.976176963403 [ if not an image trigger ]
Image S/N Ratio: 8.92
Flight Position: [ source = BAT ]
RA: 272.131488929659 Dec: -20.3976033897298 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 272.127416991447 Dec: -20.3842156435602 [deg; J2000]
{ 18h 08m 30.6s , -20d 23' 03.2" }
+/- 2.08055640411533 [arcmin] (estimated 90% radius based on SNR)
+/- 1.04282300291083 [arcmin] (formal 1-sigma fit error)
SNR: 10.6801227846992
Angular difference between Flight and Ground position is 0.835271 arcmin
Partial Coding Fraction: 1.015625 [ including projection effects ]
Duration
T90: 0.0399999618530273 +/- 0.0113137314268704
Measured from: 1.19209289550781e-07
to: 0.0400000810623169 [s; relative to TRIGTIME]
T50: 0.0119998455047607 +/- 0.0113137314268704
Measured from: 0.0120002031326294
to: 0.0240000486373901 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.47599995136261
to: 0.52400004863739 [s; relative to TRIGTIME]
Total Fluence
Measured from: 0
to: 0.0440000295639038 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.018898 0.019707 0.006505 0.000308
0.002907 0.002763 0.001791 0.001142 [error]
Peak 0.014919 0.035081 0.011961 -0.000778
0.008334 0.007753 0.006354 0.005570 [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 5.62e-09 3.50e-09 1.40e-09 7.60e-10 1.09e-08 1.13e-08 erg/cm2
Error 1.19e-09 8.18e-10 5.73e-10 5.26e-10 2.28e-09 2.45e-09 erg/cm2
Peak flux Power-law 1.99e-01 1.77e-01 1.08e-01 1.01e-01 5.27e-01 5.85e-01 ph/cm2/s
Error 1.06e-01 5.95e-02 5.23e-02 1.04e-01 1.75e-01 1.95e-01 ph/cm2/s
Fluence Cutoff-PL 5.65e-09 6.50e-09 7.36e-10 1.81e-12 1.29e-08 1.29e-08 erg/cm2
Error 1.39e-09 1.62e-09 5.63e-10 1.15e-11 2.35e-09 2.35e-09 erg/cm2
Peak flux Cutoff-PL 1.98e-01 1.77e-01 1.09e-01 1.01e-01 5.27e-01 5.82e-01 ph/cm2/s
Error 1.12e-01 6.85e-02 5.35e-02 1.16e-01 1.75e-01 2.13e-01 ph/cm2/s
Fluence Band -------- -------- -------- -------- -------- -------- erg/cm2
Error -------- -------- -------- -------- -------- -------- erg/cm2
Peak flux Band 1.68e-01 1.77e-01 1.08e-01 5.22e-02 4.85e-01 4.99e-01 ph/cm2/s
Error -------- -------- -------- 1.20e-01 -------- -------- ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 3.318 0.353 - - 1.75e-02 5.69e-03 75.800 57
CPL 1.000 0.000 50.0 0.0 5.08e-02 0.00e+00 118.280 56
The chi2 of BB fit is 58.84 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 1.707 0.657 - - 3.96e-03 1.47e-03 51.770 57
CPL 2.209 2.461 78.5 0.0 2.12e-03 0.00e+00 51.470 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 0.044 0.000 0.044
T90 0.040 0.000 0.040
T50 0.012 0.012 0.024
Peak 1.000 -0.476 0.524
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
272.1274 -20.3842 0.0181 9.4 -162.6 0.0483 10.7 TRIG_00968731
------------------------------------------
Foreground time interval of the image:
0.000 0.044 (delta_t = 0.044 [sec])
Background time interval of the image:
-78.735 0.000 (delta_t = 78.735 [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 0.000 sec. to 0.044 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 3.31775 ( -0.32004 0.386212 )
Norm@50keV : 1.75420E-02 ( -0.00567985 0.00570441 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 75.80 using 59 PHA bins.
# Reduced chi-squared = 1.330 for 57 degrees of freedom
# Null hypothesis probability = 4.859942e-02
Photon flux (15-150 keV) in 0.044 sec: 6.13479 ( -1.21639 1.21642 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.09109e-08 ( -2.27398e-09 2.2835e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 0.044 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.00000 ( )
Epeak [keV] : 50.0000 ( )
Norm@50keV : 5.08348E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 118.28 using 59 PHA bins.
# Reduced chi-squared = 2.1122 for 56 degrees of freedom
# Null hypothesis probability = 2.365608e-06
Photon flux (15-150 keV) in 0.044 sec: 7.09524 ( -1.29095 1.28901 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.28855e-08 ( -2.3529e-09 2.35677e-09 ) ergs/cm2
Band function
Time interval is from 0.000 sec. to 0.044 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 1.65703 ( -0.844687 -1.48737 )
beta : -9.97999 ( 9.97999 19.9494 )
Epeak [keV] : 24.7554 ( -3.41531 3.09688 )
Norm@50keV : 36.4182 ( -15.4138 6.46551 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.91 using 59 PHA bins.
# Reduced chi-squared = 1.071 for 55 degrees of freedom
# Null hypothesis probability = 3.343746e-01
Photon flux (15-150 keV) in 0.044 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] : 6.39199 (-0.838855 0.802113)
R^2/D10^2 : 21.7886 (-9.36909 18.7539)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.84 using 59 PHA bins.
# Reduced chi-squared = 1.032 for 57 degrees of freedom
# Null hypothesis probability = 4.080941e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 5.669e-09 1.643e-09
25- 50 6.468e-09 1.643e-09
50-150 7.625e-10 4.422e-10
15-150 1.290e-08 3.410e-09
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 17.4803 (-3.59071 4.15655)
Norm : 101.107 (-30.3724 43.2127)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 65.41 using 59 PHA bins.
# Reduced chi-squared = 1.148 for 57 degrees of freedom
# Null hypothesis probability = 2.079514e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 6.098e-09 1.309e-09
25- 50 4.784e-09 1.233e-09
50-150 1.132e-09 6.065e-10
15-150 1.201e-08 2.882e-09
Double BB
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 200.000 (-200 -200)
R1^2/D10^2 : 5.09647E-05 (-5.09653e-05 -5.09653e-05)
kT2 [keV] : 6.28887 (-0.84464 0.835676)
R2^2/D10^2 : 23.2151 (-10.2513 20.6304)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.84 using 59 PHA bins.
#Fit statistic : Chi-Squared = 58.33 using 59 PHA bins.
# Reduced chi-squared = 1.070 for 55 degrees of freedom
# Reduced chi-squared = 1.060 for 55 degrees of freedom
# Null hypothesis probability = 3.369163e-01
# Null hypothesis probability = 3.541362e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 5.670e-09 1.789e-02
25- 50 6.484e-09 1.291e-01
50-150 7.681e-10 3.654e+00
15-150 1.292e-08 3.982e+00
Peak spectrum fit
Power-law model
Time interval is from -0.476 sec. to 0.524 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.70710 ( -0.629184 0.684941 )
Norm@50keV : 3.95833E-03 ( -0.00152125 0.00142084 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.77 using 59 PHA bins.
# Reduced chi-squared = 0.9083 for 57 degrees of freedom
# Null hypothesis probability = 6.709770e-01
Photon flux (15-150 keV) in 1 sec: 0.527023 ( -0.174572 0.175136 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.66289e-08 ( -1.38113e-08 1.45779e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.476 sec. to 0.524 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.20897 ( -4.30959 0.612656 )
Epeak [keV] : 78.5451 ( )
Norm@50keV : 2.11952E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.47 using 59 PHA bins.
# Reduced chi-squared = 0.9191 for 56 degrees of freedom
# Null hypothesis probability = 6.467739e-01
Photon flux (15-150 keV) in 1 sec: 0.526785 ( -0.17432 0.175005 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.63269e-08 ( -1.56818e-08 1.47485e-08 ) ergs/cm2
Band function
Time interval is from -0.476 sec. to 0.524 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -2.37991 ( 3.28998 2.37991 )
beta : -1.70714 ( -0.685375 0.629092 )
Epeak [keV] : 99.6517 ( -99.6517 -99.6517 )
Norm@50keV : 0.537987 ( -0.206757 0.193135 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.77 using 59 PHA bins.
# Reduced chi-squared = 0.9413 for 55 degrees of freedom
# Null hypothesis probability = 5.987832e-01
Photon flux (15-150 keV) in 1 sec: 0.484705 ( ) 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] : 10.7728 (-3.29218 7.18164)
R^2/D10^2 : 0.186283 (-0.186151 0.556073)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.97 using 59 PHA bins.
# Reduced chi-squared = 0.9469 for 57 degrees of freedom
# Null hypothesis probability = 5.894374e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.497e-09 2.845e-09
25- 50 1.237e-08 7.430e-09
50-150 7.981e-09 5.595e-09
15-150 2.485e-08 1.597e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 150.471 (-108.224 -145.98)
Norm : 2.14508 (-0.742974 1.53009)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.92 using 59 PHA bins.
# Reduced chi-squared = 0.9109 for 57 degrees of freedom
# Null hypothesis probability = 6.656222e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 5.508e-09 3.304e-09
25- 50 1.021e-08 5.995e-09
50-150 2.019e-08 1.307e-08
15-150 3.591e-08 2.152e-08
Double BB
R1^2/D10^2 : 1.04945E-03 (-0.00100512 0.219725)
kT2 [keV] : 8.30503 (-8.31481 5.04571)
R2^2/D10^2 : 0.400827 (-0.399979 -0.399979)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.92 using 59 PHA bins.
#Fit statistic : Chi-Squared = 51.32 using 59 PHA bins.
#Fit statistic : Chi-Squared = 51.30 using 59 PHA bins.
# Reduced chi-squared = 0.9440 for 55 degrees of freedom
# Reduced chi-squared = 0.9330 for 55 degrees of freedom
# Reduced chi-squared = 0.9327 for 55 degrees of freedom
# Null hypothesis probability = 5.930197e-01
# Null hypothesis probability = 6.161205e-01
# Null hypothesis probability = 6.168283e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.887e-09 2.452e-09
25- 50 1.129e-08 6.930e-09
50-150 1.007e-08 7.180e-09
15-150 2.624e-08 1.594e-08
Plot creation:
Fri May 1 19:24:22 EDT 2020