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
61.6825 -2.6003 0.0073 17.7237 37.5020 2.1965366 26.542 TRIG_00783479
Foreground time interval of the image:
-1.096 37.573 (delta_t = 38.669 [sec])
Background time interval of the image:
-254.627 -1.096 (delta_t = 253.531 [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
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 4.096000
8 ms binning
From T100_start-3 s to T100_start+3 s
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 4.096000
2 ms binning
From T100_start-1 s to T100_start+1 s
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 4.096000
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 -1.096 sec. to 129.984 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.45896 ( -0.0423226 0.0422959 )
Norm@50keV : 6.18550E-03 ( -0.000134139 0.000134134 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.86 using 59 PHA bins.
# Reduced chi-squared = 0.9976 for 57 degrees of freedom
# Null hypothesis probability = 4.801383e-01
Photon flux (15-150 keV) in 131.1 sec: 0.764003 ( -0.018701 0.018762 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.74823e-06 ( -1.75848e-07 1.761e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.096 sec. to 129.984 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.30101 ( -0.169422 0.0846607 )
Epeak [keV] : 248.618 ( -99.2454 -248.618 )
Norm@50keV : 7.27436E-03 ( -0.00097881 0.00133965 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.15 using 59 PHA bins.
# Reduced chi-squared = 0.9669 for 56 degrees of freedom
# Null hypothesis probability = 5.453597e-01
Photon flux (15-150 keV) in 131.1 sec: 0.754139 ( -0.021063 0.021158 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.66466e-06 ( -1.95997e-07 1.95346e-07 ) ergs/cm2
Band function
Time interval is from -1.096 sec. to 129.984 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] : 17.6742 ( )
R^2/D10^2 : 4.73677E-02 ( )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 471.99 using 59 PHA bins.
# Reduced chi-squared = 8.2805 for 57 degrees of freedom
# Null hypothesis probability = 1.145541e-66
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.906e-07 1.855e-08
25- 50 1.782e-06 5.572e-08
50-150 4.020e-06 1.436e-07
15-150 6.193e-06 1.606e-07
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 (-4.73664 -200)
Norm : 3.16143 (-0.0686633 0.0686633)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 82.24 using 59 PHA bins.
# Reduced chi-squared = 1.443 for 57 degrees of freedom
# Null hypothesis probability = 1.598495e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.032e-06 2.596e-08
25- 50 1.986e-06 5.047e-08
50-150 4.355e-06 1.036e-07
15-150 7.374e-06 1.809e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 7.36364 (-0.593139 0.636975)
R1^2/D10^2 : 0.623130 (-0.155803 0.220998)
kT2 [keV] : 28.5069 (-2.02585 2.49416)
R2^2/D10^2 : 7.59401E-03 (-0.00193784 0.00229639)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.90 using 59 PHA bins.
# Reduced chi-squared = 0.9435 for 55 degrees of freedom
# Null hypothesis probability = 5.940159e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 8.783e-07 7.525e-08
25- 50 1.916e-06 7.932e-08
50-150 4.830e-06 2.353e-07
15-150 7.624e-06 2.878e-07
Peak spectrum fit
Power-law model
Time interval is from 62.264 sec. to 63.264 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.17580 ( -0.098982 0.098407 )
Norm@50keV : 2.59003E-02 ( -0.0015287 0.0015287 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 41.89 using 59 PHA bins.
# Reduced chi-squared = 0.7350 for 57 degrees of freedom
# Null hypothesis probability = 9.331281e-01
Photon flux (15-150 keV) in 1 sec: 3.03022 ( -0.18273 0.18288 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.64631e-07 ( -1.73561e-08 1.74345e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 62.264 sec. to 63.264 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.506636 ( -0.470522 0.424246 )
Epeak [keV] : 120.229 ( -29.091 108.757 )
Norm@50keV : 5.38758E-02 ( -0.0196049 0.0346464 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 34.28 using 59 PHA bins.
# Reduced chi-squared = 0.6122 for 56 degrees of freedom
# Null hypothesis probability = 9.902392e-01
Photon flux (15-150 keV) in 1 sec: 2.95890 ( -0.18893 0.18851 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.54812e-07 ( -1.87914e-08 1.87464e-08 ) ergs/cm2
Band function
Time interval is from 62.264 sec. to 63.264 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] : 18.6852 (-1.32814 1.46157)
R^2/D10^2 : 0.179863 (-0.0397046 0.0498279)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 66.96 using 59 PHA bins.
# Reduced chi-squared = 1.175 for 57 degrees of freedom
# Null hypothesis probability = 1.722616e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.242e-08 1.525e-09
25- 50 5.902e-08 5.315e-09
50-150 1.509e-07 1.565e-08
15-150 2.223e-07 1.580e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 (-10.419 -200)
Norm : 12.4456 (-0.751181 0.751181)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 75.61 using 59 PHA bins.
# Reduced chi-squared = 1.326 for 57 degrees of freedom
# Null hypothesis probability = 5.014444e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.098e-08 1.935e-09
25- 50 5.960e-08 4.485e-09
50-150 1.307e-07 2.821e-08
15-150 2.213e-07 3.730e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 7.70452 (-2.2421 3.67387)
R1^2/D10^2 : 1.47829 (-0.920133 2.94004)
kT2 [keV] : 26.2727 (-4.24081 13.2086)
R2^2/D10^2 : 4.87224E-02 (-0.0376345 0.0346051)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 35.32 using 59 PHA bins.
# Reduced chi-squared = 0.6421 for 55 degrees of freedom
# Null hypothesis probability = 9.820283e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.110e-08 8.384e-09
25- 50 5.830e-08 1.460e-08
50-150 1.736e-07 5.366e-08
15-150 2.530e-07 6.275e-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: 1.17194 ( -0.102886 0.10164 )
Norm@50keV : 3.51162E-03 ( -0.000203527 0.000203465 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.30 using 59 PHA bins.
# Reduced chi-squared = 0.8825 for 57 degrees of freedom
# Null hypothesis probability = 7.226785e-01
Photon flux (15-150 keV) in 38.67 sec: 0.410640 ( -0.0246495 0.0246859 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.38885e-06 ( -8.84066e-08 8.87852e-08 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.824434 ( -0.428048 0.379369 )
Epeak [keV] : 183.480 ( -72.6597 -183.48 )
Norm@50keV : 5.11638E-03 ( -0.00166603 0.00288062 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.96 using 59 PHA bins.
# Reduced chi-squared = 0.8565 for 56 degrees of freedom
# Null hypothesis probability = 7.688904e-01
Photon flux (15-150 keV) in 38.67 sec: 0.404112 ( -0.025723 0.025708 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.35815e-06 ( -9.65049e-08 9.58823e-08 ) 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) = 1.87e-06
S(50-100 keV) = 2.73e-06
T90 vs. Hardness ratio plot
T90 = 96.7719999551773 sec.
Hardness ratio (energy fluence ratio) = 1.45989
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 1.41829
Count Ratio (50-100 keV) / (15-25 keV) = 1.09808
Mask shadow pattern
IMX = 2.535455495875235E-01, IMY = -1.945664264299750E-01
TIME vs. PHA plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 4.096000
TIME vs. DetID plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 4.096000
100 us light curve (15-350 keV)
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 4.096000
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:
-254.627410 -1.096000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
83.6228 22.0181 0.3 17.4 174.9 10.3038 43.6 0.6 Crab
61.6568 0.9257 2.7 16.4 48.6 1.1159 4.3 ------ UNKNOWN
105.8944 37.6068 2.3 41.1 -169.8 1.9158 4.9 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-1.096000 37.572600
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
83.4838 22.0578 21.3 17.4 174.4 0.0406 0.5 8.7 Crab
35.8652 7.9023 2.0 41.2 70.6 1.8266 5.7 ------ UNKNOWN
35.7261 2.9221 1.7 41.6 63.0 1.9527 6.8 ------ UNKNOWN
38.6004 -36.7457 2.1 55.8 12.4 2.5068 5.5 ------ UNKNOWN
61.6825 -2.6004 0.4 17.7 37.5 2.1966 26.5 ------ UNKNOWN
62.3081 -48.3345 2.0 55.6 -12.9 1.5611 5.7 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
76.572590 962.531700
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
83.6155 22.0231 0.2 32.7 -168.2 30.2487 52.2 1.1 Crab
27.3476 20.3242 2.4 40.7 97.7 9.5653 4.9 ------ UNKNOWN
61.1391 46.3811 2.9 49.0 151.4 8.2866 4.0 ------ UNKNOWN
61.6526 -2.6051 1.5 0.0 82.5 4.0119 7.9 ------ UNKNOWN
78.1239 -3.2216 3.3 16.4 -115.6 1.9024 3.5 ------ UNKNOWN
112.0216 27.9501 3.0 57.2 -154.1 14.5080 3.9 ------ UNKNOWN
100.6154 -12.6706 4.2 39.8 -101.4 6.7954 2.8 ------ UNKNOWN
Plot creation:
Sat Jan 20 11:09:44 EST 2018