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
202.6722 38.0750 0.0092 19.3904 -34.6173 0.9661128 20.866 TRIG_00811561
Foreground time interval of the image:
-0.472 11.045 (delta_t = 11.517 [sec])
Background time interval of the image:
-239.256 -0.472 (delta_t = 238.784 [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 1.024000
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 1.024000
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 1.024000
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 -0.472 sec. to 14.572 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.10499 ( -0.170695 0.17978 )
Norm@50keV : 3.34061E-03 ( -0.000397766 0.000390573 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 37.51 using 59 PHA bins.
# Reduced chi-squared = 0.6581 for 57 degrees of freedom
# Null hypothesis probability = 9.784932e-01
Photon flux (15-150 keV) in 15.04 sec: 0.526909 ( -0.044795 0.0448 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.6713e-07 ( -4.91289e-08 5.04381e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.472 sec. to 14.572 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.48981 ( -0.959629 0.623981 )
Epeak [keV] : 32.3344 ( -28.1276 17.5372 )
Norm@50keV : 7.80513E-03 ( -0.004868 0.0221186 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 35.63 using 59 PHA bins.
# Reduced chi-squared = 0.6363 for 56 degrees of freedom
# Null hypothesis probability = 9.845923e-01
Photon flux (15-150 keV) in 15.04 sec: 0.512171 ( -0.048139 0.048232 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.32541e-07 ( -5.95164e-08 6.49641e-08 ) ergs/cm2
Band function
Time interval is from -0.472 sec. to 14.572 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.49043 ( -3.40415 0.204276 )
beta : -10.00000 ( 10 20 )
Epeak [keV] : 32.3244 ( -8.48763 17.7087 )
Norm@50keV : 7.79680E-03 ( -0.000660284 0.0221439 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 35.63 using 59 PHA bins.
# Reduced chi-squared = 0.6479 for 55 degrees of freedom
# Null hypothesis probability = 9.801594e-01
Photon flux (15-150 keV) in 15.04 sec: 0.512110 ( -0.047391 0.047398 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.36696e-07 ( 7.05135e-08 1.63232e-07 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 8.94190 (-0.83043 0.923791)
R^2/D10^2 : 0.368637 (-0.118226 0.172943)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.16 using 59 PHA bins.
# Reduced chi-squared = 0.9327 for 57 degrees of freedom
# Null hypothesis probability = 6.198472e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 8.602e-08 1.199e-08
25- 50 1.810e-07 2.181e-08
50-150 6.768e-08 1.920e-08
15-150 3.347e-07 3.610e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 53.0932 (-12.0041 18.2239)
Norm : 2.87421 (-0.408777 0.518831)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 35.72 using 59 PHA bins.
# Reduced chi-squared = 0.6266 for 57 degrees of freedom
# Null hypothesis probability = 9.877951e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.071e-07 1.217e-08
25- 50 1.570e-07 1.569e-08
50-150 1.612e-07 4.576e-08
15-150 4.253e-07 5.256e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 6.53935 (-3.0585 1.57927)
R1^2/D10^2 : 0.976429 (-0.490017 0.684616)
kT2 [keV] : 21.5239 (-10.4885 35.8838)
R2^2/D10^2 : 6.90198E-03 (-0.00622393 0.116761)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 37.30 using 59 PHA bins.
# Reduced chi-squared = 0.6782 for 55 degrees of freedom
# Null hypothesis probability = 9.676412e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.025e-07 3.733e-08
25- 50 1.587e-07 5.278e-08
50-150 1.766e-07 9.748e-08
15-150 4.378e-07 1.714e-07
Peak spectrum fit
Power-law model
Time interval is from 0.396 sec. to 1.396 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.89884 ( -0.227452 0.241389 )
Norm@50keV : 9.99795E-03 ( -0.00159957 0.00155718 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 48.72 using 59 PHA bins.
# Reduced chi-squared = 0.8548 for 57 degrees of freedom
# Null hypothesis probability = 7.742589e-01
Photon flux (15-150 keV) in 1 sec: 1.43420 ( -0.17831 0.1783 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.19327e-08 ( -1.41684e-08 1.4587e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.396 sec. to 1.396 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.37834 ( -1.15884 0.800107 )
Epeak [keV] : 48.7573 ( )
Norm@50keV : 2.02420E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.81 using 59 PHA bins.
# Reduced chi-squared = 0.8538 for 56 degrees of freedom
# Null hypothesis probability = 7.736899e-01
Photon flux (15-150 keV) in 1 sec: 1.40688 ( -0.18414 0.18444 ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Band function
Time interval is from 0.396 sec. to 1.396 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.845250 ( -0.8207 -0.8207 )
beta : -2.14075 ( -2.00537 0.384395 )
Epeak [keV] : 29.1798 ( -29.1381 156.107 )
Norm@50keV : 0.860212 ( -0.748063 651.532 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.14 using 59 PHA bins.
# Reduced chi-squared = 0.8570 for 55 degrees of freedom
# Null hypothesis probability = 7.656099e-01
Photon flux (15-150 keV) in 1 sec: 1.41536 ( -0.18163 0.18016 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.24209e-08 ( 1.16692e-08 4.30566e-08 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 9.81854 (-1.41872 1.69154)
R^2/D10^2 : 0.722109 (-0.326341 0.58359)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.58 using 59 PHA bins.
# Reduced chi-squared = 1.045 for 57 degrees of freedom
# Null hypothesis probability = 3.820805e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.409e-08 3.082e-09
25- 50 3.412e-08 6.340e-09
50-150 1.688e-08 5.836e-09
15-150 6.509e-08 1.159e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 75.4463 (-25.8294 52.2675)
Norm : 6.88549 (-1.20382 1.51976)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.81 using 59 PHA bins.
# Reduced chi-squared = 0.8387 for 57 degrees of freedom
# Null hypothesis probability = 8.019936e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.779e-08 3.120e-09
25- 50 2.887e-08 4.555e-09
50-150 3.914e-08 1.930e-08
15-150 8.579e-08 2.043e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 6.13692 (-2.003 2.15924)
R1^2/D10^2 : 3.01477 (-1.88285 8.84761)
kT2 [keV] : 20.6203 (-7.41674 25.767)
R2^2/D10^2 : 2.87412E-02 (-0.0265137 0.143861)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.17 using 59 PHA bins.
# Reduced chi-squared = 0.8576 for 55 degrees of freedom
# Null hypothesis probability = 7.646338e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.790e-08 1.016e-08
25- 50 2.813e-08 1.470e-08
50-150 3.904e-08 2.233e-08
15-150 8.507e-08 4.510e-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: 2.09052 ( -0.156811 0.163848 )
Norm@50keV : 4.23213E-03 ( -0.000458091 0.000450699 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.47 using 59 PHA bins.
# Reduced chi-squared = 0.7801 for 57 degrees of freedom
# Null hypothesis probability = 8.866962e-01
Photon flux (15-150 keV) in 11.52 sec: 0.662726 ( -0.0523705 0.0523794 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.5257e-07 ( -4.3792e-08 4.48084e-08 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.45628 ( -0.942481 0.573642 )
Epeak [keV] : 33.0474 ( )
Norm@50keV : 1.02172E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 42.26 using 59 PHA bins.
# Reduced chi-squared = 0.7546 for 56 degrees of freedom
# Null hypothesis probability = 9.128970e-01
Photon flux (15-150 keV) in 11.52 sec: 0.643414 ( -0.056664 0.056554 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.16718e-07 ( -5.54769e-08 5.976e-08 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.758585 ( -0.95312 4.3562 )
beta : -2.52611 ( 2.52582 0.435182 )
Epeak [keV] : 31.9758 ( -9.37875 8.15524 )
Norm@50keV : 2.98744E-02 ( -0.0308645 107.161 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 40.20 using 59 PHA bins.
# Reduced chi-squared = 0.7309 for 55 degrees of freedom
# Null hypothesis probability = 9.328070e-01
Photon flux (15-150 keV) in 11.52 sec: 0.662782 ( -0.052376 0.052385 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.5265e-07 ( -4.3754e-08 4.48039e-08 ) ergs/cm2
S(25-50 keV) vs. S(50-100 keV) plot
S(25-50 keV) = 1.45e-07
S(50-100 keV) = 1.35e-07
T90 vs. Hardness ratio plot
T90 = 10.9199999570847 sec.
Hardness ratio (energy fluence ratio) = 0.931034
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 1.07705
Count Ratio (50-100 keV) / (15-25 keV) = 0.400136
Mask shadow pattern
IMX = 2.896559014788390E-01, IMY = 1.999493210829509E-01
TIME vs. PHA plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 1.024000
TIME vs. DetID plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 1.024000
100 us light curve (15-350 keV)
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 1.024000
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:
-239.256000 -0.472000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
194.9327 33.4589 3.4 14.1 -14.5 0.7365 3.4 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-0.472000 11.044600
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
189.9599 -6.8495 2.3 45.2 49.6 0.9673 5.1 ------ UNKNOWN
229.8938 4.1730 2.1 57.5 -2.0 1.4967 5.6 ------ UNKNOWN
202.6722 38.0750 0.6 19.4 -34.6 0.9661 20.9 ------ UNKNOWN
104.2023 48.7745 2.4 53.3 -166.0 0.6704 4.7 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
63.644600 962.807700
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.4493 35.3753 6.3 41.1 -78.6 5.8218 1.8 2.0 Her X-1
174.5791 11.4671 3.1 36.5 74.9 5.3515 3.8 ------ UNKNOWN
168.8708 29.7963 2.8 29.0 107.8 3.7716 4.2 ------ UNKNOWN
232.8636 75.8129 3.2 40.1 -144.8 3.8671 3.6 ------ UNKNOWN
244.5979 0.2250 3.9 54.0 -31.6 8.2406 3.0 ------ UNKNOWN
Plot creation:
Sat Apr 7 22:33:47 EDT 2018