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
278.9615 52.6269 0.0142 23.1736 -2.2798 0.0691768 13.627 TRIG_00208275
Foreground time interval of the image:
-0.004 0.172 (delta_t = 0.176 [sec])
Background time interval of the image:
-239.204 -0.004 (delta_t = 239.200 [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 0.064000
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 0.064000
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 0.064000
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 -0.004 sec. to 0.172 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.984509 ( -0.205259 0.197722 )
Norm@50keV : 2.56841E-02 ( -0.00314486 0.00313586 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.96 using 59 PHA bins.
# Reduced chi-squared = 0.9993 for 57 degrees of freedom
# Null hypothesis probability = 4.766408e-01
Photon flux (15-150 keV) in 0.176 sec: 2.95479 ( -0.366024 0.366637 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.91383e-08 ( -6.43296e-09 6.50403e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.004 sec. to 0.172 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.105197 ( -1.17757 0.886986 )
Epeak [keV] : 117.948 ( -39.4884 -117.948 )
Norm@50keV : 6.61782E-02 ( -0.04076 0.157349 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.26 using 59 PHA bins.
# Reduced chi-squared = 0.9688 for 56 degrees of freedom
# Null hypothesis probability = 5.411845e-01
Photon flux (15-150 keV) in 0.176 sec: 2.87298 ( -0.38047 0.3785 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.67423e-08 ( -7.27338e-09 7.13117e-09 ) ergs/cm2
Band function
Time interval is from -0.004 sec. to 0.172 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.546195 ( -1.31184 -0.571254 )
beta : -1.51633 ( 1.5189 0.533818 )
Epeak [keV] : 81.2762 ( -44.4733 83.3163 )
Norm@50keV : 0.148926 ( -0.163463 75.8879 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.73 using 59 PHA bins.
# Reduced chi-squared = 0.9587 for 55 degrees of freedom
# Null hypothesis probability = 5.619241e-01
Photon flux (15-150 keV) in 0.176 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] : 20.1947 (-2.76028 3.48036)
R^2/D10^2 : 0.142765 (-0.0572333 0.0872227)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.64 using 59 PHA bins.
# Reduced chi-squared = 1.029 for 57 degrees of freedom
# Null hypothesis probability = 4.151712e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.968e-09 4.327e-10
25- 50 9.865e-09 1.738e-09
50-150 2.986e-08 6.486e-09
15-150 4.169e-08 7.647e-09
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 ( )
Norm : 11.8513 (-1.513 1.51296)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 76.59 using 59 PHA bins.
# Reduced chi-squared = 1.344 for 57 degrees of freedom
# Null hypothesis probability = 4.277783e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 5.192e-09 2.894e-09
25- 50 9.988e-09 5.574e-09
50-150 2.190e-08 1.215e-08
15-150 3.709e-08 2.065e-08
Double BB
R1^2/D10^2 : 0.291293 ( )
kT2 [keV] : 200.000 ( )
R2^2/D10^2 : 3.91947E-04 (-0.000224063 0.00302798)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.91 using 59 PHA bins.
#Fit statistic : Chi-Squared = 51.61 using 59 PHA bins.
#Fit statistic : Chi-Squared = 51.60 using 59 PHA bins.
# Reduced chi-squared = 0.9439 for 55 degrees of freedom
# Reduced chi-squared = 0.9384 for 55 degrees of freedom
# Reduced chi-squared = 0.9382 for 55 degrees of freedom
# Null hypothesis probability = 5.933217e-01
# Null hypothesis probability = 6.048194e-01
# Null hypothesis probability = 6.052946e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.594e-09 1.486e-09
25- 50 1.050e-08 6.095e-09
50-150 3.412e-08 1.752e-08
15-150 4.721e-08 2.292e-08
Peak spectrum fit
Power-law model
Time interval is from -0.408 sec. to 0.592 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.814690 ( -0.378748 0.342204 )
Norm@50keV : 5.35001E-03 ( -0.00112329 0.00109114 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 65.16 using 59 PHA bins.
# Reduced chi-squared = 1.143 for 57 degrees of freedom
# Null hypothesis probability = 2.141249e-01
Photon flux (15-150 keV) in 1 sec: 0.614589 ( -0.123735 0.124873 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.21366e-08 ( -1.24883e-08 1.25852e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.408 sec. to 0.592 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.457426 ( -2.30007 0.551984 )
Epeak [keV] : 256.891 ( -341.421 -341.421 )
Norm@50keV : 7.56337E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.94 using 59 PHA bins.
# Reduced chi-squared = 1.160 for 56 degrees of freedom
# Null hypothesis probability = 1.932098e-01
Photon flux (15-150 keV) in 1 sec: 0.603698 ( -0.131134 0.130434 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.09801e-08 ( -1.39701e-08 1.31905e-08 ) ergs/cm2
Band function
Time interval is from -0.408 sec. to 0.592 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.854745 ( 0.854745 0.854745 )
beta : -0.814688 ( -0.342197 0.378644 )
Epeak [keV] : 15.3337 ( -15.3337 -15.3337 )
Norm@50keV : 7.72121E-03 ( -0.00346787 0 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 65.16 using 59 PHA bins.
# Reduced chi-squared = 1.185 for 55 degrees of freedom
# Null hypothesis probability = 1.642048e-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] : 24.4081 (-5.6586 9.31356)
R^2/D10^2 : 1.65918E-02 (-0.0102168 0.0213228)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 67.12 using 59 PHA bins.
# Reduced chi-squared = 1.177 for 57 degrees of freedom
# Null hypothesis probability = 1.689595e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.739e-09 7.226e-10
25- 50 9.743e-09 3.836e-09
50-150 4.317e-08 1.599e-08
15-150 5.466e-08 2.170e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 ( )
Norm : 2.50147 (-0.520868 0.52081)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 77.41 using 59 PHA bins.
# Reduced chi-squared = 1.358 for 57 degrees of freedom
# Null hypothesis probability = 3.732565e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 6.233e-09 3.688e-09
25- 50 1.199e-08 7.025e-09
50-150 2.630e-08 1.532e-08
15-150 4.452e-08 2.576e-08
Double BB
------------------------------------------------------------
#Fit statistic : Chi-Squared = 66.01 using 59 PHA bins.
#Fit statistic : Chi-Squared = 64.39 using 59 PHA bins.
#Fit statistic : Chi-Squared = 64.29 using 59 PHA bins.
#Fit statistic : Chi-Squared = 64.21 using 59 PHA bins.
# Reduced chi-squared = 1.200 for 55 degrees of freedom
# Reduced chi-squared = 1.171 for 55 degrees of freedom
# Reduced chi-squared = 1.169 for 55 degrees of freedom
# Reduced chi-squared = 1.168 for 55 degrees of freedom
# Null hypothesis probability = 1.470116e-01
# Null hypothesis probability = 1.808964e-01
# Null hypothesis probability = 1.832901e-01
# Null hypothesis probability = 1.849896e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.213e-09 1.990e-09
25- 50 9.244e-09 4.938e-09
50-150 4.479e-08 2.600e-08
15-150 5.725e-08 3.143e-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: 0.984509 ( -0.205259 0.197722 )
Norm@50keV : 2.56841E-02 ( -0.00314486 0.00313586 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.96 using 59 PHA bins.
# Reduced chi-squared = 0.9993 for 57 degrees of freedom
# Null hypothesis probability = 4.766408e-01
Photon flux (15-150 keV) in 0.176 sec: 2.95479 ( -0.366024 0.366637 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.91383e-08 ( -6.43296e-09 6.50403e-09 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.105197 ( -1.17757 0.886986 )
Epeak [keV] : 117.948 ( -39.4884 -117.948 )
Norm@50keV : 6.61782E-02 ( -0.04076 0.157349 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.26 using 59 PHA bins.
# Reduced chi-squared = 0.9688 for 56 degrees of freedom
# Null hypothesis probability = 5.411845e-01
Photon flux (15-150 keV) in 0.176 sec: 2.87298 ( -0.38047 0.3785 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.67423e-08 ( -7.27338e-09 7.13117e-09 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.546195 ( -1.31184 -0.571254 )
beta : -1.51633 ( 1.5189 0.533818 )
Epeak [keV] : 81.2762 ( -44.4733 83.3163 )
Norm@50keV : 0.148926 ( -0.163463 75.8685 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.73 using 59 PHA bins.
# Reduced chi-squared = 0.9587 for 55 degrees of freedom
# Null hypothesis probability = 5.619241e-01
Photon flux (15-150 keV) in 0.176 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) = 9.01e-09
S(50-100 keV) = 1.82e-08
T90 vs. Hardness ratio plot
T90 = 0.143999993801117 sec.
Hardness ratio (energy fluence ratio) = 2.01998
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 2.56275
Count Ratio (50-100 keV) / (15-25 keV) = 2.89411
Mask shadow pattern
IMX = 4.277172360753796E-01, IMY = 1.702765592760256E-02
TIME vs. PHA plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 0.064000
TIME vs. DetID plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 0.064000
100 us light curve (15-350 keV)
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 0.064000
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:
-239.204000 -0.004000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.5182 35.3604 2.0 32.2 48.5 1.7895 5.9 3.2 Her X-1
299.5934 35.1977 0.5 45.7 -7.5 7.6849 23.4 0.3 Cyg X-1
308.2401 41.1354 0.0 44.0 -20.1 -0.3293 -1.1 12.4 Cyg X-3
326.2671 38.1966 0.0 53.6 -33.9 0.4770 0.5 8.8 Cyg X-2
14.8768 68.8429 3.1 40.9 -87.1 3.2845 3.7 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-0.004000 0.172000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.4158 35.2768 11.4 32.3 48.6 0.0088 1.0 4.4 Her X-1
299.7345 35.1788 14.1 45.8 -7.6 -0.0075 -0.8 7.2 Cyg X-1
307.9743 40.8321 152.1 44.2 -19.6 0.0007 0.1 9.5 Cyg X-3
326.2043 38.2853 30.7 53.5 -33.9 -0.0080 -0.4 2.7 Cyg X-2
278.9615 52.6269 0.8 23.2 -2.3 0.0692 13.6 ------ UNKNOWN
139.8548 43.8415 2.6 54.5 -170.9 0.0651 4.4 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
54.496590 962.846800
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.4447 35.3133 0.9 24.5 88.6 8.5507 12.3 1.9 Her X-1
288.8186 10.9581 1.1 42.4 19.4 10.2839 10.8 1.4 GRS 1915+105
299.5900 35.2024 0.2 22.7 -14.4 32.8112 66.3 0.1 Cyg X-1
307.9242 40.9284 5.9 22.8 -37.0 0.9911 2.0 8.6 Cyg X-3
326.1975 38.3245 4.3 35.3 -51.6 1.9256 2.7 1.2 Cyg X-2
254.8539 26.6079 2.6 31.6 77.9 4.1894 4.4 ------ UNKNOWN
140.6897 63.8636 3.2 59.1 -166.2 14.1297 3.7 ------ UNKNOWN
106.7038 80.0343 2.9 47.3 -148.0 4.6771 3.9 ------ UNKNOWN
Plot creation:
Sun May 31 13:22:59 EDT 2015