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
265.4217 0.7375 0.0108 38.8899 42.7936 8.1516094 17.814 TRIG_00814677
Foreground time interval of the image:
-79.728 24.373 (delta_t = 104.101 [sec])
Background time interval of the image:
-166.827 -79.728 (delta_t = 87.099 [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 -79.728 sec. to 37.272 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.45777 ( -0.122295 0.12149 )
Norm@50keV : 4.39700E-03 ( -0.00030383 0.000303667 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.74 using 59 PHA bins.
# Reduced chi-squared = 1.031 for 57 degrees of freedom
# Null hypothesis probability = 4.115180e-01
Photon flux (15-150 keV) in 117 sec: 0.542933 ( -0.039992 0.040104 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.91649e-06 ( -3.61728e-07 3.63289e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -79.728 sec. to 37.272 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.45444 ( -0.417854 0.176962 )
Epeak [keV] : 8969.30 ( -8894.61 -8894.61 )
Norm@50keV : 4.41381E-03 ( -0.000306443 0.00301079 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.74 using 59 PHA bins.
# Reduced chi-squared = 1.049 for 56 degrees of freedom
# Null hypothesis probability = 3.754294e-01
Photon flux (15-150 keV) in 117 sec: 0.542598 ( -0.041354 0.040517 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.9122e-06 ( -3.87539e-07 3.66245e-07 ) ergs/cm2
Band function
Time interval is from -79.728 sec. to 37.272 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 4.33706 ( -5.12997 -4.33705 )
beta : -1.55166 ( -0.159088 0.141661 )
Epeak [keV] : 27.0168 ( -10.4928 20.9863 )
Norm@50keV : 94.1199 ( -94.2247 1475.59 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.61 using 59 PHA bins.
# Reduced chi-squared = 1.011 for 55 degrees of freedom
# Null hypothesis probability = 4.517293e-01
Photon flux (15-150 keV) in 117 sec: 0.532768 ( -0.041407 0.042001 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.9442e-06 ( -4.19226e-07 3.34489e-07 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 15.8118 ( )
R^2/D10^2 : 5.05621E-02 ( )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 117.57 using 59 PHA bins.
# Reduced chi-squared = 2.0626 for 57 degrees of freedom
# Null hypothesis probability = 4.262346e-06
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.066e-07 4.382e-08
25- 50 1.277e-06 1.282e-07
50-150 2.221e-06 2.755e-07
15-150 3.805e-06 3.492e-07
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 (-31.3747 -200)
Norm : 2.24849 (-0.155434 0.155434)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.81 using 59 PHA bins.
# Reduced chi-squared = 1.084 for 57 degrees of freedom
# Null hypothesis probability = 3.083082e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 6.551e-07 5.493e-08
25- 50 1.260e-06 1.010e-07
50-150 2.764e-06 5.909e-07
15-150 4.679e-06 7.979e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 8.86231 (-1.51538 1.65331)
R1^2/D10^2 : 0.291455 (-0.123155 0.245673)
kT2 [keV] : 43.6883 (-13.3782 45.545)
R2^2/D10^2 : 1.35128E-03 (-0.00109626 0.00284224)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.54 using 59 PHA bins.
# Reduced chi-squared = 0.9917 for 55 degrees of freedom
# Null hypothesis probability = 4.919748e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 5.537e-07 1.220e-07
25- 50 1.328e-06 2.652e-07
50-150 3.097e-06 1.360e-06
15-150 4.979e-06 1.608e-06
Peak spectrum fit
Power-law model
Time interval is from 1.272 sec. to 2.272 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.20511 ( -0.235644 0.226142 )
Norm@50keV : 2.83008E-02 ( -0.0037532 0.00374399 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 70.24 using 59 PHA bins.
# Reduced chi-squared = 1.232 for 57 degrees of freedom
# Null hypothesis probability = 1.119084e-01
Photon flux (15-150 keV) in 1 sec: 3.32436 ( -0.46548 0.46817 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.86741e-07 ( -3.99382e-08 4.01026e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.272 sec. to 2.272 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.41284 ( -0.294203 0.224518 )
Epeak [keV] : 135.511 ( -9999.36 -9999.36 )
Norm@50keV : 4.08136E-03 ( -0.00407692 0.0060101 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 69.63 using 59 PHA bins.
# Reduced chi-squared = 1.243 for 56 degrees of freedom
# Null hypothesis probability = 1.042650e-01
Photon flux (15-150 keV) in 1 sec: 3.32871 ( -0.47892 0.47127 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.87184e-07 ( -4.05971e-08 3.51751e-08 ) ergs/cm2
Band function
Time interval is from 1.272 sec. to 2.272 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 4.52906 ( -10.3569 -4.52906 )
beta : -1.51191 ( -0.374561 0.333571 )
Epeak [keV] : 36.9654 ( -7.84897 14.4737 )
Norm@50keV : 131.901 ( -17.158 2959.21 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 67.17 using 59 PHA bins.
# Reduced chi-squared = 1.221 for 55 degrees of freedom
# Null hypothesis probability = 1.257665e-01
Photon flux (15-150 keV) in 1 sec: 3.32436 ( -0.46548 0.46817 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.86741e-07 ( -3.99382e-08 4.01026e-08 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 16.6019 (-2.97928 4.3997)
R^2/D10^2 : 0.278869 (-0.152321 0.27652)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 86.16 using 59 PHA bins.
# Reduced chi-squared = 1.512 for 57 degrees of freedom
# Null hypothesis probability = 7.579024e-03
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.575e-08 4.080e-09
25- 50 6.837e-08 1.570e-08
50-150 1.335e-07 3.412e-08
15-150 2.176e-07 4.090e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 (-40.9054 -200)
Norm : 14.0684 (-1.88998 1.88998)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 76.99 using 59 PHA bins.
# Reduced chi-squared = 1.351 for 57 degrees of freedom
# Null hypothesis probability = 3.999624e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.505e-08 1.972e-08
25- 50 6.743e-08 3.794e-08
50-150 1.479e-07 8.235e-08
15-150 2.504e-07 1.373e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 10.6065 (-2.17929 2.0531)
R1^2/D10^2 : 1.03167 (-0.424493 0.861556)
kT2 [keV] : 98.8852 (-150.137 -199.363)
R2^2/D10^2 : 1.61162E-03 (-0.000140255 0.00664852)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.95 using 59 PHA bins.
# Reduced chi-squared = 1.126 for 55 degrees of freedom
# Null hypothesis probability = 2.419728e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.502e-08 9.357e-09
25- 50 7.265e-08 3.577e-08
50-150 1.924e-07 1.391e-07
15-150 2.900e-07 1.508e-07
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: 1.40069 ( -0.121449 0.120175 )
Norm@50keV : 4.68786E-03 ( -0.00032309 0.000323089 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.10 using 59 PHA bins.
# Reduced chi-squared = 1.054 for 57 degrees of freedom
# Null hypothesis probability = 3.640225e-01
Photon flux (15-150 keV) in 104.1 sec: 0.570985 ( -0.042231 0.0423581 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.71477e-06 ( -3.44855e-07 3.45813e-07 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.29753 ( -0.482114 0.208144 )
Epeak [keV] : 332.267 ( -378.637 -378.637 )
Norm@50keV : 5.26407E-03 ( -0.000831051 0.00354066 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.03 using 59 PHA bins.
# Reduced chi-squared = 1.072 for 56 degrees of freedom
# Null hypothesis probability = 3.320307e-01
Photon flux (15-150 keV) in 104.1 sec: 0.568554 ( -0.043533 0.043594 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.69018e-06 ( -3.68962e-07 3.63101e-07 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 4.89788 ( -12.3713 -4.89788 )
beta : -1.50973 ( -0.164458 0.142063 )
Epeak [keV] : 27.6161 ( -5.19733 4.17182 )
Norm@50keV : 211.491 ( -14.5194 1118.41 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.66 using 59 PHA bins.
# Reduced chi-squared = 1.012 for 55 degrees of freedom
# Null hypothesis probability = 4.498382e-01
Photon flux (15-150 keV) in 104.1 sec: 3.62683E-03 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 4.6395e-06 ( -3.50353e-07 3.48552e-07 ) ergs/cm2
S(25-50 keV) vs. S(50-100 keV) plot
S(25-50 keV) = 1.19e-06
S(50-100 keV) = 1.73e-06
T90 vs. Hardness ratio plot
T90 = 87 sec.
Hardness ratio (energy fluence ratio) = 1.45378
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 1.6826
Count Ratio (50-100 keV) / (15-25 keV) = 1.15584
Mask shadow pattern
IMX = 5.918939788582531E-01, IMY = -5.479761629433119E-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:
-166.827400 -79.728000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.4075 35.2161 17.9 39.2 101.5 -0.4302 -0.6 8.0 Her X-1
268.3728 -1.4557 85.3 38.1 37.0 -0.0396 -0.1 0.3 SW J1753.5-0127
270.3493 -25.1386 75.3 55.6 14.6 -0.1423 -0.2 5.0 GX 5-1
273.9285 -14.1655 7.7 44.4 18.3 -0.4732 -1.5 9.0 GX 17+2
285.1234 -24.9916 4.9 50.2 -0.8 -0.9281 -2.4 6.4 HT1900.1-2455
288.7729 10.9644 1.5 15.3 20.0 1.2957 7.8 1.9 GRS 1915+105
299.5693 35.1914 0.6 11.7 171.0 3.3138 20.9 1.2 Cyg X-1
308.0590 40.9110 2.2 19.3 -172.0 0.8860 5.3 3.4 Cyg X-3
326.1684 38.1818 7.6 28.1 -143.7 0.2899 1.5 8.4 Cyg X-2
258.1880 67.3566 2.6 50.1 145.4 3.6848 4.4 ------ UNKNOWN
275.0951 7.1891 0.5 27.3 40.8 5.4665 25.4 ------ UNKNOWN
359.5707 55.4390 2.9 54.8 -158.2 2.9791 4.0 ------ UNKNOWN
2.5623 54.8266 5.1 56.4 -157.2 2.4276 2.3 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-79.728000 24.372590
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.2830 35.2682 8.1 39.4 101.5 1.2795 1.4 9.6 Her X-1
268.2575 -1.4906 5.7 38.2 37.1 -0.8383 -2.0 7.0 SW J1753.5-0127
270.3567 -25.2519 8.8 55.7 14.5 1.8379 1.3 11.1 GX 5-1
273.9597 -14.1183 12.7 44.4 18.3 0.4229 0.9 5.6 GX 17+2
285.0718 -24.9208 264.8 50.1 -0.7 0.0228 0.0 1.9 HT1900.1-2455
288.9745 11.0536 4.9 15.1 19.6 -0.5060 -2.3 12.2 GRS 1915+105
299.5385 35.3706 10.9 11.8 170.8 0.2368 1.0 10.5 Cyg X-1
307.9647 40.8791 3.1 19.2 -172.1 -0.7860 -3.7 7.9 Cyg X-3
326.0627 38.4584 6.9 28.2 -144.3 -0.4325 -1.7 9.7 Cyg X-2
265.4217 0.7375 0.6 38.9 42.8 8.1528 17.8 ------ UNKNOWN
275.0371 7.1583 2.3 27.4 40.9 1.3992 5.0 ------ UNKNOWN
336.0311 52.4187 2.0 40.8 -160.7 2.0002 5.7 ------ UNKNOWN
351.0853 34.9959 2.7 47.2 -132.5 3.5651 4.3 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
81.772600 962.348600
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
244.9837 -15.6353 0.3 26.0 48.6 62.1457 39.6 0.4 Sco X-1
254.3043 35.3060 8.8 36.1 162.9 -2.4989 -1.3 7.8 Her X-1
255.9872 -37.8514 1.8 39.6 10.2 10.4967 6.6 0.4 4U 1700-377
256.5772 -36.5821 6.7 38.2 10.0 2.7886 1.7 11.7 GX 349+2
262.8649 -24.5968 76.7 25.5 3.9 -0.1807 -0.2 11.9 GX 1+4
264.6026 -44.3081 17.7 45.0 -0.7 1.4931 0.7 10.4 4U 1735-44
268.3376 -1.5064 9.4 3.6 -53.7 1.4136 1.2 3.7 SW J1753.5-0127
270.4324 -24.9283 493.9 26.1 -11.9 -0.0282 -0.0 12.1 GX 5-1
270.2270 -25.8150 3.6 26.9 -11.1 3.8489 3.2 5.9 GRS 1758-258
273.8681 -13.9305 9.8 16.9 -30.9 1.3725 1.2 10.2 GX 17+2
275.7772 -30.3253 6.2 32.6 -18.3 2.4618 1.9 8.0 H1820-303
284.9300 -25.0757 7.0 32.0 -36.4 2.3954 1.7 11.0 HT1900.1-2455
288.7880 10.9236 1.3 25.3 -116.2 13.7434 8.6 1.4 GRS 1915+105
299.5731 35.2065 1.0 46.9 -142.7 38.5955 11.1 0.9 Cyg X-1
262.8847 -33.7696 7.8 34.6 2.2 2.0472 1.5 6.5 GX 354-0
276.4576 52.9643 2.3 53.0 -173.3 17.8952 5.0 ------ UNKNOWN
275.0876 7.1899 0.2 11.6 -125.8 57.5087 48.9 ------ UNKNOWN
275.3741 -14.5339 2.6 18.1 -33.9 5.1298 4.5 ------ UNKNOWN
288.7247 -7.3181 3.1 24.6 -72.1 6.0177 3.7 ------ UNKNOWN
305.0594 31.7070 3.3 48.5 -135.2 16.1020 3.5 ------ UNKNOWN
306.4324 5.1381 4.3 41.1 -98.6 14.7247 2.7 ------ UNKNOWN
UNKNOWN
Plot creation:
Sat Apr 7 22:22:31 EDT 2018