Special notes of this burst
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
201.9396 21.4043 0.0162 34.1447 10.3286 0.9422493 11.893 TRIG_00832119
Foreground time interval of the image:
29.000 55.000 (delta_t = 26.000 [sec])
Background time interval of the image:
-239.000 29.000 (delta_t = 268.000 [sec])
Lightcurves
Notes:
- 1) The mask-weighted light curves are using the flight position.
- 2) Multiple plots of different time binning/intervals are shown to cover all scenarios of short/long GRBs, rate/image triggers, and real/false positives.
- 3) 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.
- 4) 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.
- 5) 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)
Quad-rate summed light curves (from T0-300s to T0+1000s)
Spectral Evolution
Spectra
Notes:
- 1) The fitting includes the systematic errors.
- 2) When the burst includes telescope slew time periods, the fitting uses an average response file made from multiple 5-s response files through out the slew time plus single time preiod for the non-slew times, and weighted by the total counts in the corresponding time period using addrmf. An average response file is needed becuase a spectral fit using 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.
Time averaged spectrum fit using the average DRM
Power-law model
Time interval is from 29.000 sec. to 55.000 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.10065 ( -0.261723 0.283929 )
Norm@50keV : 1.75668E-03 ( -0.00034457 0.000335489 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.88 using 59 PHA bins.
# Reduced chi-squared = 0.9628 for 57 degrees of freedom
# Null hypothesis probability = 5.551419e-01
Photon flux (15-150 keV) in 26 sec: 0.276483 ( -0.038983 0.038983 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.24466e-07 ( -7.35899e-08 7.61602e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 29.000 sec. to 55.000 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.36653 ( -2.28795 0.709577 )
Epeak [keV] : 31.6550 ( )
Norm@50keV : 5.08059E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.02 using 59 PHA bins.
# Reduced chi-squared = 0.9646 for 56 degrees of freedom
# Null hypothesis probability = 5.503599e-01
Photon flux (15-150 keV) in 26 sec: 0.276930 ( -0.039485 0.038562 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.85003e-07 ( -9.17426e-08 1.02294e-07 ) ergs/cm2
Band function
Time interval is from 29.000 sec. to 55.000 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : ( )
beta : ( )
Epeak [keV] : ( )
Norm@50keV : ( )
------------------------------------------------------------
Photon flux (15-150 keV) in 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] : 8.11461 (-1.15912 1.38288)
R^2/D10^2 : 0.292084 (-0.136208 0.248648)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.12 using 59 PHA bins.
# Reduced chi-squared = 1.020 for 57 degrees of freedom
# Null hypothesis probability = 4.337911e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 9.137e-08 2.384e-08
25- 50 1.639e-07 3.626e-08
50-150 4.508e-08 1.963e-08
15-150 3.003e-07 5.620e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 50.0785 (-16.5935 31.6678)
Norm : 1.57340 (-0.3577 0.503881)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.96 using 59 PHA bins.
# Reduced chi-squared = 0.9466 for 57 degrees of freedom
# Null hypothesis probability = 5.899135e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.001e-07 1.820e-08
25- 50 1.438e-07 2.386e-08
50-150 1.398e-07 5.817e-08
15-150 3.837e-07 8.359e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 6.86005 (-1.53527 1.55435)
R1^2/D10^2 : 0.505838 (-0.243266 0.428535)
kT2 [keV] : 35.8178 (-27.6432 -43.8869)
R2^2/D10^2 : 5.82399E-04 (-0.000338359 0.00988244)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.96 using 59 PHA bins.
# Reduced chi-squared = 0.9083 for 55 degrees of freedom
# Null hypothesis probability = 6.671812e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.000e-07 4.602e-08
25- 50 1.460e-07 6.620e-08
50-150 1.675e-07 9.686e-08
15-150 4.135e-07 1.942e-07
Peak spectrum fit
Power-law model
Time interval is from 54.000 sec. to 55.000 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.80234 ( -0.823817 1.33003 )
Norm@50keV : 2.68782E-03 ( -0.00268692 0.00201436 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 77.84 using 59 PHA bins.
# Reduced chi-squared = 1.366 for 57 degrees of freedom
# Null hypothesis probability = 3.475302e-02
Photon flux (15-150 keV) in 1 sec: 0.642855 ( -0.204729 0.204721 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.96982e-08 ( -1.25148e-08 1.447e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 54.000 sec. to 55.000 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 3.43502 ( -1.38463 0.0321507 )
Epeak [keV] : 411.272 ( -93.2369 -412.095 )
Norm@50keV : 1.33210E-03 ( -0.00132215 0.00313651 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 77.53 using 59 PHA bins.
# Reduced chi-squared = 1.384 for 56 degrees of freedom
# Null hypothesis probability = 2.998592e-02
Photon flux (15-150 keV) in 1 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Band function
Time interval is from 54.000 sec. to 55.000 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : ( )
beta : ( )
Epeak [keV] : ( )
Norm@50keV : ( )
------------------------------------------------------------
Photon flux (15-150 keV) in 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] : 4.01813 (-1.34451 3.01746)
R^2/D10^2 : 14.2413 (-14.2627 130.828)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 81.58 using 59 PHA bins.
# Reduced chi-squared = 1.431 for 57 degrees of freedom
# Null hypothesis probability = 1.803240e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.324e-08 7.795e-09
25- 50 4.842e-09 3.244e-09
50-150 6.048e-11 7.055e-11
15-150 1.814e-08 1.111e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 25.2852 (-18.9275 69.3082)
Norm : 5.82045 (-3.38062 41.1616)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 79.64 using 59 PHA bins.
# Reduced chi-squared = 1.397 for 57 degrees of freedom
# Null hypothesis probability = 2.549317e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.074e-08 6.585e-09
25- 50 1.109e-08 7.093e-09
50-150 4.793e-09 4.255e-09
15-150 2.662e-08 1.654e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 3.10108 (-1.27481 1.71306)
R1^2/D10^2 : 48.6657 (-44.1251 1581.32)
kT2 [keV] : 16.6457 (-7.74182 21.7906)
R2^2/D10^2 : 2.61529E-02 (-0.0244038 0.134227)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 75.57 using 59 PHA bins.
# Reduced chi-squared = 1.374 for 55 degrees of freedom
# Null hypothesis probability = 3.431632e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.263e-08 7.625e-09
25- 50 8.276e-09 4.444e-09
50-150 1.269e-08 9.420e-09
15-150 3.359e-08 1.791e-08
Pre-slew spectrum (Pre-slew PHA with pre-slew DRM)
Power-law model
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.10065 ( -0.261723 0.283929 )
Norm@50keV : 1.75668E-03 ( -0.00034457 0.000335489 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.88 using 59 PHA bins.
# Reduced chi-squared = 0.9628 for 57 degrees of freedom
# Null hypothesis probability = 5.551419e-01
Photon flux (15-150 keV) in 26 sec: 0.276459 ( -0.0389795 0.0389795 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.24382e-07 ( -7.35194e-08 7.61917e-08 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.36988 ( -2.29056 0.708981 )
Epeak [keV] : 31.6458 ( )
Norm@50keV : 5.05479E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.02 using 59 PHA bins.
# Reduced chi-squared = 0.9646 for 56 degrees of freedom
# Null hypothesis probability = 5.503589e-01
Photon flux (15-150 keV) in 26 sec: 0.269844 ( -0.040982 0.040814 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.85112e-07 ( -9.18268e-08 1.01993e-07 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : ( )
beta : ( )
Epeak [keV] : ( )
Norm@50keV : ( )
------------------------------------------------------------
Photon flux (15-150 keV) in sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
S(25-50 keV) vs. S(50-100 keV) plot
S(25-50 keV) = 1.31e-07
S(50-100 keV) = 1.22e-07
T90 vs. Hardness ratio plot
T90 = 24 sec.
Hardness ratio (energy fluence ratio) = 0.931298
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 1.2056
Count Ratio (50-100 keV) / (15-25 keV) = 0.421398
Mask shadow pattern
IMX = 6.671994961526532E-01, IMY = -1.215945848633981E-01
TIME vs. PHA plot around the trigger time
TIME vs. DetID plot around the trigger time
100 us light curve (15-350 keV)
Spacecraft aspect plot
Bright source in the pre-burst/pre-slew/post-slew images
Pre-burst image of 15-350 keV band
Time interval of the image:
-239.000000 29.000000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
135.4833 -40.5410 10.7 55.0 -148.4 2.0475 1.1 2.2 Vela X-1
170.3697 -60.5679 8.3 52.6 175.2 1.2692 1.4 3.7 Cen X-3
186.6104 -62.7474 7.7 53.3 165.2 1.8696 1.5 1.9 GX 301-2
216.6622 32.1777 2.2 50.3 18.0 3.3723 5.3 ------ UNKNOWN
195.2707 13.2413 3.1 24.1 5.1 0.9938 3.7 ------ UNKNOWN
138.9448 -24.0844 3.0 48.0 -129.0 4.9432 3.9 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
29.000000 55.000000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
135.5470 -40.5226 6.5 55.0 -148.4 0.6044 1.8 2.1 Vela X-1
170.4517 -60.6406 4.0 52.7 175.1 0.6452 2.9 4.1 Cen X-3
186.4649 -62.7346 10.2 53.3 165.3 0.3266 1.1 5.7 GX 301-2
190.0561 -44.1808 2.6 34.9 161.2 0.3818 4.4 ------ UNKNOWN
201.9396 21.4045 1.0 34.1 10.3 0.9417 11.9 ------ UNKNOWN
192.9440 26.8005 2.9 36.7 -6.1 0.3159 4.0 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
196.300590 383.700610
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.4403 35.2339 14.4 47.7 7.8 -0.2833 -0.8 6.6 Her X-1
204.5790 -10.3928 2.5 31.9 121.7 1.4150 4.6 ------ UNKNOWN
237.0891 12.7835 2.6 34.6 45.2 1.4547 4.5 ------ UNKNOWN
161.0449 -4.9617 2.6 48.0 -172.0 1.8514 4.5 ------ UNKNOWN
254.0456 53.8988 2.6 50.8 -16.5 1.7962 4.5 ------ UNKNOWN
Plot creation:
Thu May 31 18:03:35 EDT 2018