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
98.1452 -58.6882 0.0141 39.5736 -2.2116 0.4073248 13.663 TRIG_00796469
Foreground time interval of the image:
0.032 2.640 (delta_t = 2.608 [sec])
Background time interval of the image:
-239.088 0.032 (delta_t = 239.120 [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 0.032 sec. to 2.640 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.74744 ( -0.200938 0.208255 )
Norm@50keV : 1.00223E-02 ( -0.00132557 0.00130467 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.04 using 59 PHA bins.
# Reduced chi-squared = 0.9481 for 57 degrees of freedom
# Null hypothesis probability = 5.867262e-01
Photon flux (15-150 keV) in 2.608 sec: 1.35397 ( -0.16329 0.16345 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.41261e-07 ( -3.26887e-08 3.30966e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.032 sec. to 2.640 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.04280 ( -1.11293 0.79733 )
Epeak [keV] : 61.0718 ( -17.0392 -61.0712 )
Norm@50keV : 2.45209E-02 ( -0.0153326 0.0783989 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.12 using 59 PHA bins.
# Reduced chi-squared = 0.9307 for 56 degrees of freedom
# Null hypothesis probability = 6.226159e-01
Photon flux (15-150 keV) in 2.608 sec: 1.32288 ( -0.16861 0.16814 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.27226e-07 ( -3.7237e-08 3.74522e-08 ) ergs/cm2
Band function
Time interval is from 0.032 sec. to 2.640 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] : 11.4437 (-1.49244 1.77444)
R^2/D10^2 : 0.398614 (-0.166287 0.272645)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.44 using 59 PHA bins.
# Reduced chi-squared = 1.095 for 57 degrees of freedom
# Null hypothesis probability = 2.890653e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.864e-08 6.026e-09
25- 50 8.512e-08 1.344e-08
50-150 6.485e-08 1.710e-08
15-150 1.786e-07 2.712e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 112.391 (-40.5742 83.2573)
Norm : 5.84229 (-0.859602 1.12781)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.27 using 59 PHA bins.
# Reduced chi-squared = 0.9171 for 57 degrees of freedom
# Null hypothesis probability = 6.527475e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.977e-08 6.781e-09
25- 50 7.033e-08 1.325e-08
50-150 1.214e-07 5.966e-08
15-150 2.315e-07 6.469e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 8.39063 (-2.1554 2.11822)
R1^2/D10^2 : 0.995368 (-0.512914 1.4423)
kT2 [keV] : 32.7929 (-14.6641 -32.9363)
R2^2/D10^2 : 5.16393E-03 (-0.00508777 0.0432746)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.65 using 59 PHA bins.
# Reduced chi-squared = 0.9027 for 55 degrees of freedom
# Null hypothesis probability = 6.784724e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.630e-08 1.863e-08
25- 50 7.852e-08 3.428e-08
50-150 1.197e-07 6.694e-08
15-150 2.345e-07 9.775e-08
Peak spectrum fit
Power-law model
Time interval is from 0.036 sec. to 1.036 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.55197 ( -0.195765 0.199384 )
Norm@50keV : 1.78537E-02 ( -0.00226748 0.0022499 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 74.75 using 59 PHA bins.
# Reduced chi-squared = 1.311 for 57 degrees of freedom
# Null hypothesis probability = 5.738340e-02
Photon flux (15-150 keV) in 1 sec: 2.26154 ( -0.27859 0.27887 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.68051e-07 ( -2.28666e-08 2.30927e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.036 sec. to 1.036 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.795935 ( -1.01312 0.793333 )
Epeak [keV] : 75.2830 ( -22.1524 -75.2834 )
Norm@50keV : 4.52688E-02 ( -0.0277997 0.114592 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 72.13 using 59 PHA bins.
# Reduced chi-squared = 1.288 for 56 degrees of freedom
# Null hypothesis probability = 7.218848e-02
Photon flux (15-150 keV) in 1 sec: 2.21705 ( -0.28313 0.28311 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.59071e-07 ( -2.54884e-08 2.52862e-08 ) ergs/cm2
Band function
Time interval is from 0.036 sec. to 1.036 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] : 12.8399 (-1.75777 2.15924)
R^2/D10^2 : 0.456256 (-0.19632 0.320145)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 82.41 using 59 PHA bins.
# Reduced chi-squared = 1.446 for 57 degrees of freedom
# Null hypothesis probability = 1.549264e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.595e-08 3.635e-09
25- 50 5.421e-08 9.770e-09
50-150 5.610e-08 1.515e-08
15-150 1.263e-07 2.134e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 184.359 (-79.0081 -184.22)
Norm : 9.33605 (-1.16092 1.33264)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 72.92 using 59 PHA bins.
# Reduced chi-squared = 1.279 for 57 degrees of freedom
# Null hypothesis probability = 7.599422e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.348e-08 1.317e-08
25- 50 4.474e-08 2.396e-08
50-150 9.554e-08 5.270e-08
15-150 1.637e-07 8.810e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 9.00999 (-2.00635 2.19211)
R1^2/D10^2 : 1.23508 (-0.617362 1.11994)
kT2 [keV] : 35.5034 (-13.6541 90.9173)
R2^2/D10^2 : 8.06512E-03 (-0.00803426 0.0417513)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 67.87 using 59 PHA bins.
# Reduced chi-squared = 1.234 for 55 degrees of freedom
# Null hypothesis probability = 1.141570e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.096e-08 9.577e-09
25- 50 5.095e-08 2.317e-08
50-150 9.253e-08 5.162e-08
15-150 1.644e-07 7.449e-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: 1.74744 ( -0.200938 0.208255 )
Norm@50keV : 1.00223E-02 ( -0.00132557 0.00130467 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.04 using 59 PHA bins.
# Reduced chi-squared = 0.9481 for 57 degrees of freedom
# Null hypothesis probability = 5.867262e-01
Photon flux (15-150 keV) in 2.608 sec: 1.35391 ( -0.163283 0.163438 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.41223e-07 ( -3.26759e-08 3.31088e-08 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.04245 ( -1.11284 0.797403 )
Epeak [keV] : 61.0599 ( -17.0391 -61.0701 )
Norm@50keV : 2.45327E-02 ( -0.0150164 0.0783827 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.12 using 59 PHA bins.
# Reduced chi-squared = 0.9307 for 56 degrees of freedom
# Null hypothesis probability = 6.226159e-01
Photon flux (15-150 keV) in 2.608 sec: 1.32268 ( -0.16857 0.16808 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.27291e-07 ( -3.72146e-08 3.74996e-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) = 6.65e-08
S(50-100 keV) = 7.93e-08
T90 vs. Hardness ratio plot
T90 = 2.17600005865097 sec.
Hardness ratio (energy fluence ratio) = 1.19248
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 1.5714
Count Ratio (50-100 keV) / (15-25 keV) = 0.940992
Mask shadow pattern
IMX = 8.258796853203473E-01, IMY = 3.189422191671311E-02
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:
-239.088000 0.032000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
135.6431 -40.4459 3.2 10.4 -18.8 0.8357 3.6 8.4 Vela X-1
170.3663 -60.5596 262.3 36.4 -60.0 0.0206 0.0 4.1 Cen X-3
156.9738 6.3927 2.7 40.6 172.8 1.7327 4.3 ------ UNKNOWN
66.3645 -64.9835 3.4 55.5 -5.3 2.6847 3.4 ------ UNKNOWN
178.3628 -19.3475 3.0 36.9 -133.1 1.4442 3.9 ------ UNKNOWN
55.4301 -81.0907 4.4 58.9 -24.4 4.4290 2.6 ------ UNKNOWN
160.7376 -80.4555 3.0 50.7 -39.2 3.8316 3.8 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
0.032000 2.640000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
135.2809 -40.5579 12.0 10.6 -17.6 0.0190 1.0 11.3 Vela X-1
170.1234 -60.6865 13.3 36.4 -59.7 0.0336 0.9 6.8 Cen X-3
163.7685 17.1835 2.3 53.2 174.8 0.3951 4.9 ------ UNKNOWN
98.1452 -58.6882 0.8 39.6 -2.2 0.4108 13.8 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
76.012600 963.022000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
135.4983 -40.5397 1.6 29.7 177.1 4.0406 7.0 1.6 Vela X-1
170.0188 -60.7266 0.0 34.5 -127.0 -0.9402 -1.0 10.7 Cen X-3
186.6134 -62.7451 3.9 40.0 -117.2 4.4931 3.0 1.9 GX 301-2
49.1435 -24.0043 3.0 48.7 41.8 8.6229 3.9 ------ UNKNOWN
37.4178 -42.7367 2.9 39.9 14.1 3.0818 4.0 ------ UNKNOWN
159.1368 -21.5479 2.3 56.8 -175.2 12.8193 4.9 ------ UNKNOWN
6.9734 -59.6162 3.5 43.0 -23.9 2.8882 3.3 ------ UNKNOWN
311.4731 -75.1433 2.8 44.4 -60.2 11.5840 4.1 ------ UNKNOWN
287.2363 -78.6973 2.3 42.5 -69.2 12.1680 5.1 ------ UNKNOWN
Plot creation:
Sat Jan 20 09:47:30 EST 2018