batgrbproduct Analysis for Trigger=686761
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 10 downlinks after the trigger.
======================================================================
BAT GRB EVENT DATA PROCESSING REPORT
Process Script Ver: batgrbproduct v2.46
Process Start Time (local time): Thu May 19 12:16:32 EDT 2016
Host Name: bat1
Current Working Dir: /local/data/bat1/prebascript/trigger686761/GCN5_download_cron
======================================================================
Trigger: 00686761 Segment: 000
BAT Trigger Time: 485255380.244 [s; MET]
Trigger Stop: 485255380.26 [s; MET]
UTC: 2016-05-18T09:09:23.958660 [includes UTCF correction]
Where From?: (*SHORT BURST*) TDRSS scaled map message
BAT
RA: 293.722461595314 Dec: 21.8910956484575 [deg; J2000]
Catalogged Source?: YES
Point Source?: YES
GRB Indicated?: NO [ by BAT flight software ]
Image S/N Ratio: 24.16
Image Trigger?: NO
Rate S/N Ratio: 255.998046867549 [ if not an image trigger ]
Image S/N Ratio: 24.16
Flight Position: [ source = BAT ]
RA: 293.722461595314 Dec: 21.8910956484575 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 293.72753769189 Dec: 21.8914024205546 [deg; J2000]
{ 19h 34m 54.6s , +21d 53' 29.0" }
+/- 0.455095527860558 [arcmin] (estimated 90% radius based on SNR)
+/- 0.148013191766966 [arcmin] (formal 1-sigma fit error)
SNR: 93.657655736819
Angular difference between Flight and Ground position is 0.283203 arcmin
Partial Coding Fraction: 0.984375 [ including projection effects ]
Duration
T90: 0.12799996137619 +/- 0.004
Measured from: -0.0479999184608459
to: 0.0800000429153442 [s; relative to TRIGTIME]
T50: 0.0679999589920044 +/- 0.004
Measured from: -0.0199999213218689
to: 0.0480000376701355 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.486000001430511
to: 0.513999998569489 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.0720000267028809
to: 0.0959999561309814 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 2.032181 2.162640 0.445415 0.008820
0.021684 0.022189 0.010383 0.002215 [error]
Peak 2.033533 2.166442 0.449657 0.007714
0.022385 0.022852 0.011460 0.004706 [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 9.98e-07 6.48e-07 2.72e-07 1.57e-07 2.00e-06 2.07e-06 erg/cm2
Error -------- -------- -------- -------- -------- -------- erg/cm2
Peak flux Power-law 3.09e+01 1.30e+01 3.24e+00 9.88e-01 4.77e+01 4.81e+01 ph/cm2/s
Error -------- -------- -------- -------- -------- -------- ph/cm2/s
Fluence Cutoff-PL 6.00e-07 8.97e-07 3.29e-07 1.59e-08 1.84e-06 1.84e-06 erg/cm2
Error 3.55e-08 2.15e-08 1.27e-08 2.98e-09 4.78e-08 4.79e-08 erg/cm2
Peak flux Cutoff-PL 1.94e+01 1.64e+01 3.33e+00 9.45e-02 3.93e+01 3.93e+01 ph/cm2/s
Error 1.23e+00 4.09e-01 1.35e-01 2.07e-02 1.39e+00 1.39e+00 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 3.249 0.000 - - 8.73e-01 0.00e+00 1114.720 57
CPL -0.242 0.260 29.5 1.2 6.42e+01 2.11e+01 60.120 56
The chi2 of BB fit is 130.78 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 3.005 0.000 - - 1.73e-01 0.00e+00 682.570 57
CPL -0.165 0.290 29.4 1.3 9.71e+00 3.66e+00 59.990 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: 0.128000 sec.
T50 in the 50-300 keV band: 0.064000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 0.168 -0.072 0.096
T90 0.128 -0.048 0.080
T50 0.068 -0.020 0.048
Peak 1.000 -0.486 0.514
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
293.7275 +21.8914 0.0021 12.0 -120.5 4.7825 93.7 TRIG_00686761
------------------------------------------
Foreground time interval of the image:
-0.072 0.096 (delta_t = 0.168 [sec])
Background time interval of the image:
-239.244 -0.072 (delta_t = 239.172 [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 -0.072 sec. to 0.096 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 3.24866 ( )
Norm@50keV : 0.873192 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 1114.72 using 59 PHA bins.
# Reduced chi-squared = 19.5565 for 57 degrees of freedom
# Null hypothesis probability = 5.298077e-196
Photon flux (15-150 keV) in 0.168 sec: 289.424 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 1.99656e-06 ( 0 0 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.072 sec. to 0.096 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.241560 ( -0.266435 0.253222 )
Epeak [keV] : 29.5420 ( -1.28799 1.1803 )
Norm@50keV : 64.2241 ( -17.1506 24.9553 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.12 using 59 PHA bins.
# Reduced chi-squared = 1.074 for 56 degrees of freedom
# Null hypothesis probability = 3.290575e-01
Photon flux (15-150 keV) in 0.168 sec: 232.329 ( -8.019 8.103 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.84187e-06 ( 0 0 ) ergs/cm2
Band function
Time interval is from -0.072 sec. to 0.096 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.237143 ( -0.239013 0.281906 )
beta : -10.0000 ( 10 10 )
Epeak [keV] : 29.5151 ( -1.2685 1.20242 )
Norm@50keV : 63.9143 ( -16.7599 25.5357 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.12 using 59 PHA bins.
# Reduced chi-squared = 1.093 for 55 degrees of freedom
# Null hypothesis probability = 2.955675e-01
Photon flux (15-150 keV) in 0.168 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] : 8.65223 ( )
R^2/D10^2 : 194.090 ( )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 130.78 using 59 PHA bins.
# Reduced chi-squared = 2.2943 for 57 degrees of freedom
# Null hypothesis probability = 9.984940e-08
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.650e-07 1.806e-08
25- 50 9.283e-07 2.134e-08
50-150 3.134e-07 1.294e-08
15-150 1.707e-06 3.830e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 25.3858 ( )
Norm : 2583.22 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 205.77 using 59 PHA bins.
# Reduced chi-squared = 3.6101 for 57 degrees of freedom
# Null hypothesis probability = 1.074447e-18
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 8.027e-07 2.495e-08
25- 50 8.308e-07 1.831e-08
50-150 3.613e-07 1.386e-08
15-150 1.995e-06 4.368e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 6.09721 (-0.852644 0.812092)
R1^2/D10^2 : 477.039 (-127.055 255.022)
kT2 [keV] : 10.6720 (-0.75452 1.18042)
R2^2/D10^2 : 44.7650 (-25.4812 32.9941)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.95 using 59 PHA bins.
# Reduced chi-squared = 1.054 for 55 degrees of freedom
# Null hypothesis probability = 3.670847e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 5.828e-07 5.947e-08
25- 50 9.013e-07 7.896e-08
50-150 3.444e-07 4.964e-08
15-150 1.829e-06 1.695e-07
Peak spectrum fit
Power-law model
Time interval is from -0.486 sec. to 0.514 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 3.00450 ( )
Norm@50keV : 0.172940 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 682.57 using 59 PHA bins.
# Reduced chi-squared = 11.975 for 57 degrees of freedom
# Null hypothesis probability = 5.262400e-108
Photon flux (15-150 keV) in 1 sec: 47.7171 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 2.08222e-06 ( 0 0 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.486 sec. to 0.514 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.165448 ( -0.296652 0.282391 )
Epeak [keV] : 29.3748 ( -1.40573 1.25808 )
Norm@50keV : 9.71383 ( -2.9075 4.41524 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.99 using 59 PHA bins.
# Reduced chi-squared = 1.071 for 56 degrees of freedom
# Null hypothesis probability = 3.330984e-01
Photon flux (15-150 keV) in 1 sec: 39.2562 ( -1.3826 1.3971 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.85301e-06 ( 0 0 ) ergs/cm2
Band function
Time interval is from -0.486 sec. to 0.514 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.434609 ( -0.420301 0.329406 )
beta : -5.41709 ( -1.05985 0.452095 )
Epeak [keV] : 30.0230 ( -1.46127 0.901632 )
Norm@50keV : 13.9860 ( -5.07049 7.74099 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.75 using 59 PHA bins.
# Reduced chi-squared = 1.014 for 55 degrees of freedom
# Null hypothesis probability = 4.462507e-01
Photon flux (15-150 keV) in 1 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 1.85418e-06 ( 0 0 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 8.58626 ( )
R^2/D10^2 : 33.8319 ( )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 123.70 using 59 PHA bins.
# Reduced chi-squared = 2.1702 for 57 degrees of freedom
# Null hypothesis probability = 7.735324e-07
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.730e-07 1.920e-08
25- 50 9.325e-07 2.185e-08
50-150 3.074e-07 1.350e-08
15-150 1.713e-06 3.950e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 26.9234 ( )
Norm : 404.330 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 159.37 using 59 PHA bins.
# Reduced chi-squared = 2.7960 for 57 degrees of freedom
# Null hypothesis probability = 1.264511e-11
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 7.753e-07 2.735e-08
25- 50 8.322e-07 2.005e-08
50-150 3.935e-07 1.690e-08
15-150 2.001e-06 4.250e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 6.46117 (-0.98398 0.849981)
R1^2/D10^2 : 73.5394 (-18.4371 37.6015)
kT2 [keV] : 11.4407 (-1.28458 2.52588)
R2^2/D10^2 : 4.63522 (-3.52225 6.47288)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.76 using 59 PHA bins.
# Reduced chi-squared = 1.032 for 55 degrees of freedom
# Null hypothesis probability = 4.093440e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 5.780e-07 5.575e-08
25- 50 9.046e-07 9.705e-08
50-150 3.533e-07 9.865e-08
15-150 1.836e-06 2.340e-07
Plot creation:
Thu May 19 12:21:15 EDT 2016