Special notes of this burst
Image
Pre-slew 15.0-350.0 keV image (Event data; DETECTION mask)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
43.4818 13.3906 0.0113 53.8855 -31.5773 7.9354411 17.017 TRIG_00548760
Foreground time interval of the image:
-6.136 102.472 (delta_t = 108.608 [sec])
Background time interval of the image:
-239.416 -6.136 (delta_t = 233.280 [sec])
Lightcurves
Notes:
- 1) All plots contain as much data as has been downloaded to date.
- 2) The mask-weighted light curves are using the flight position.
- 3) Multiple plots of different time binning/intervals are shown to cover all scenarios of short/long GRBs, rate/image triggers, and real/false positives.
- 4) 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.
- 5) 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.
- 6) 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 16.384000
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 16.384000
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 16.384000
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) For long bursts, a spectral fit of 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.
- 4) For short bursts (T90<1sec), the specrtum is also fit with Blackbody, OTTB, and Double Blackbody.
Time averaged spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -6.168 sec. to 73.384 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.60548 ( -0.134709 0.136244 )
Norm@50keV : 7.26353E-03 ( -0.000579458 0.000578118 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 66.54 using 59 PHA bins.
# Reduced chi-squared = 1.167 for 57 degrees of freedom
# Null hypothesis probability = 1.814761e-01
Photon flux (15-150 keV) in 79.55 sec: 0.934984 ( -0.0778517 0.0781132 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.40024e-06 ( -4.52653e-07 4.5421e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -6.168 sec. to 73.384 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.17896 ( -0.577609 0.482186 )
Epeak [keV] : 101.572 ( -33.8657 -101.572 )
Norm@50keV : 1.16915E-02 ( -0.00471181 0.0101825 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.57 using 59 PHA bins.
# Reduced chi-squared = 1.153 for 56 degrees of freedom
# Null hypothesis probability = 2.021598e-01
Photon flux (15-150 keV) in 79.55 sec: 0.916022 ( -0.080001 0.081171 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.29194e-06 ( -4.78374e-07 4.76401e-07 ) ergs/cm2
Band function
Time interval is from -6.168 sec. to 73.384 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.17901 ( -0.374155 0.530212 )
beta : -10.0000 ( 10 1.77636e-15 )
Epeak [keV] : 101.562 ( -27.086 -101.562 )
Norm@50keV : 1.16895E-02 ( -0.00471218 0.010187 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.57 using 59 PHA bins.
# Reduced chi-squared = 1.174 for 55 degrees of freedom
# Null hypothesis probability = 1.769842e-01
Photon flux (15-150 keV) in 79.55 sec: 0.912825 ( 6.08718 -0.077714 ) 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] : 15.3660 (-1.49488 1.66717)
R^2/D10^2 : 9.52053E-02 (-0.0294126 0.042397)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 101.92 using 59 PHA bins.
# Reduced chi-squared = 1.7881 for 57 degrees of freedom
# Null hypothesis probability = 2.380886e-04
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.728e-07 6.101e-08
25- 50 1.514e-06 1.694e-07
50-150 2.459e-06 3.671e-07
15-150 4.346e-06 4.383e-07
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 180.778 (-55.7787 -181.338)
Norm : 3.81872 (-0.324372 0.366944)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.64 using 59 PHA bins.
# Reduced chi-squared = 1.134 for 57 degrees of freedom
# Null hypothesis probability = 2.272013e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 7.657e-07 1.161e-07
25- 50 1.456e-06 5.351e-07
50-150 3.087e-06 1.538e-06
15-150 5.308e-06 2.215e-06
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 7.14233 (-1.50641 1.74324)
R1^2/D10^2 : 0.931522 (-0.48564 1.24661)
kT2 [keV] : 25.8339 (-4.80584 8.26763)
R2^2/D10^2 : 1.14814E-02 (-0.00729367 0.0138719)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.46 using 59 PHA bins.
# Reduced chi-squared = 1.136 for 55 degrees of freedom
# Null hypothesis probability = 2.283221e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 7.238e-07 2.561e-07
25- 50 1.482e-06 4.800e-07
50-150 3.110e-06 1.498e-06
15-150 5.317e-06 1.952e-06
Peak spectrum fit
Power-law model
Time interval is from 11.164 sec. to 12.164 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.62711 ( -0.431896 0.454516 )
Norm@50keV : 1.98715E-02 ( -0.00522379 0.00518065 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.95 using 59 PHA bins.
# Reduced chi-squared = 1.034 for 57 degrees of freedom
# Null hypothesis probability = 4.040835e-01
Photon flux (15-150 keV) in 1 sec: 2.57550 ( -0.698338 0.704505 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.85257e-07 ( -5.04663e-08 5.08635e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 11.164 sec. to 12.164 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.11287 ( )
Epeak [keV] : 45.0937 ( )
Norm@50keV : 9.10864E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.49 using 59 PHA bins.
# Reduced chi-squared = 1.044 for 56 degrees of freedom
# Null hypothesis probability = 3.840708e-01
Photon flux (15-150 keV) in 1 sec: 2.51036 ( -0.73951 0.73196 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.80954e-07 ( -5.6129e-08 5.3015e-08 ) ergs/cm2
Band function
Time interval is from 11.164 sec. to 12.164 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.167224 ( 0.430207 0.430207 )
beta : -2.02724 ( 2.01092 0.768794 )
Epeak [keV] : 56.7725 ( -57.5521 188.29 )
Norm@50keV : 0.116936 ( -0.121237 3.54506e+06 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.40 using 59 PHA bins.
# Reduced chi-squared = 1.062 for 55 degrees of freedom
# Null hypothesis probability = 3.516671e-01
Photon flux (15-150 keV) in 1 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] : 14.4375 (-3.48008 5.01877)
R^2/D10^2 : 0.339255 (-0.227214 0.57857)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.44 using 59 PHA bins.
# Reduced chi-squared = 1.060 for 57 degrees of freedom
# Null hypothesis probability = 3.527504e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.489e-08 7.522e-09
25- 50 5.706e-08 2.958e-08
50-150 7.952e-08 4.546e-08
15-150 1.515e-07 6.850e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 171.124 (-105.182 -170.6)
Norm : 10.5688 (-2.83357 4.07712)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.70 using 59 PHA bins.
# Reduced chi-squared = 1.030 for 57 degrees of freedom
# Null hypothesis probability = 4.127776e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.680e-08 1.564e-08
25- 50 5.059e-08 2.945e-08
50-150 1.052e-07 6.305e-08
15-150 1.826e-07 1.070e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 1.71027 (-1.7249 13.8373)
R1^2/D10^2 : 5613.03 (-4966.73 3.8552e+09)
kT2 [keV] : 15.4836 (-3.94883 5.4317)
R2^2/D10^2 : 0.252884 (-0.248778 0.124494)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.93 using 59 PHA bins.
# Reduced chi-squared = 1.053 for 55 degrees of freedom
# Null hypothesis probability = 3.678405e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.444e-08 9.980e-09
25- 50 5.175e-08 3.189e-08
50-150 8.536e-08 5.370e-08
15-150 1.616e-07 9.098e-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: 1.60548 ( -0.134709 0.136244 )
Norm@50keV : 7.26353E-03 ( -0.000579458 0.000578118 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 66.54 using 59 PHA bins.
# Reduced chi-squared = 1.167 for 57 degrees of freedom
# Null hypothesis probability = 1.814761e-01
Photon flux (15-150 keV) in 79.55 sec: 0.934984 ( -0.0778517 0.0781132 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.40024e-06 ( -4.52653e-07 4.5421e-07 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.17896 ( -0.577609 0.482186 )
Epeak [keV] : 101.572 ( -33.8657 -101.572 )
Norm@50keV : 1.16915E-02 ( -0.00471181 0.0101825 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.57 using 59 PHA bins.
# Reduced chi-squared = 1.153 for 56 degrees of freedom
# Null hypothesis probability = 2.021598e-01
Photon flux (15-150 keV) in 79.55 sec: 0.916022 ( -0.080001 0.081171 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.29194e-06 ( -4.78374e-07 4.76401e-07 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.17901 ( -0.374155 0.530212 )
beta : -10.0000 ( 10 5.32907e-15 )
Epeak [keV] : 101.562 ( -27.086 -101.562 )
Norm@50keV : 1.16895E-02 ( -0.00471218 0.010187 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.57 using 59 PHA bins.
# Reduced chi-squared = 1.174 for 55 degrees of freedom
# Null hypothesis probability = 1.769842e-01
Photon flux (15-150 keV) in 79.55 sec: 0.912825 ( 6.08718 -0.077714 ) 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) = 1.40e-06
S(50-100 keV) = 1.84e-06
T90 vs. Hardness ratio plot
T90 = 66.2240000367165 sec.
Hardness ratio (energy fluence ratio) = 1.31429
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 1.57129
Count Ratio (50-100 keV) / (15-25 keV) = 1.36867
Mask shadow pattern (with DETECTION mask)
IMX = 1.167673035019286E+00, IMY = 7.177203054069740E-01
TIME vs. PHA plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 16.384000
TIME vs. DetID plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 16.384000
100 us light curve (15-350 keV)
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 16.384000
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:
-239.416000 -6.168000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
83.6425 22.0351 0.4 35.4 19.3 9.1168 31.3 1.3 Crab
135.5257 -40.5453 1.5 47.8 165.4 4.9710 7.9 0.6 Vela X-1
67.8630 20.1642 2.7 40.0 -4.0 1.3049 4.2 ------ UNKNOWN
85.0156 -18.0662 2.4 8.0 -102.5 0.9605 4.8 ------ UNKNOWN
68.4790 9.7126 2.4 31.7 -15.0 1.1251 4.8 ------ UNKNOWN
72.8708 -33.8943 2.7 27.0 -113.9 1.1192 4.2 ------ UNKNOWN
42.4046 2.8102 3.5 50.8 -44.4 4.2434 3.3 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-6.168000 73.384000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
83.6594 22.1952 0.0 35.6 19.3 -0.5752 -3.6 10.9 Crab
135.5349 -40.4136 5.6 47.8 165.2 -0.6049 -2.1 8.5 Vela X-1
116.2548 6.7520 2.5 31.6 84.9 0.8974 4.6 ------ UNKNOWN
43.4866 13.3871 0.7 53.9 -31.6 8.0857 17.3 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
903.084600 962.625800
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
135.5274 -40.5150 1.8 24.4 68.2 0.6467 6.3 2.4 Vela X-1
170.7274 -60.6837 0.0 8.3 -170.7 0.0123 0.2 12.6 Cen X-3
187.1054 -62.7763 0.0 15.2 -150.3 0.0357 0.5 12.3 GX 301-2
63.8157 -36.4710 2.3 58.2 -5.7 2.3597 5.0 ------ UNKNOWN
254.1571 -55.8680 2.3 46.7 -126.1 1.7990 5.1 ------ UNKNOWN
284.0619 -72.5256 3.1 41.0 -97.2 1.3418 3.7 ------ UNKNOWN
Plot creation:
Fri Dec 18 19:27:57 EST 2015