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
337.4166 19.5606 0.0071 20.4379 128.3230 1.9030202 27.367 TRIG_00151207
Foreground time interval of the image:
-20.472 19.101 (delta_t = 39.573 [sec])
Background time interval of the image:
-299.800 -20.472 (delta_t = 279.328 [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 -20.472 sec. to 240.888 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.24058 ( -0.100279 0.10024 )
Norm@50keV : 1.46066E-03 ( -7.92048e-05 7.90019e-05 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 45.57 using 59 PHA bins.
# Reduced chi-squared = 0.7995 for 57 degrees of freedom
# Null hypothesis probability = 8.616495e-01
Photon flux (15-150 keV) in 261.4 sec: 0.172495 ( -0.00930265 0.00930804 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.83076e-06 ( -2.44219e-07 2.46282e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -20.472 sec. to 240.888 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.24009 ( -0.10326 0.0985933 )
Epeak [keV] : 9999.32 ( -9999.36 -9999.36 )
Norm@50keV : 1.46559E-03 ( -7.93471e-05 0.00054237 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 45.59 using 59 PHA bins.
# Reduced chi-squared = 0.8142 for 56 degrees of freedom
# Null hypothesis probability = 8.383909e-01
Photon flux (15-150 keV) in 261.4 sec: 0.172444 ( -0.009309 0.009292 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.82428e-06 ( -2.45716e-07 2.49689e-07 ) ergs/cm2
Band function
Time interval is from -20.472 sec. to 240.888 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 4.42258 ( -4.42258 -4.42258 )
beta : -1.29657 ( -0.115552 0.110881 )
Epeak [keV] : 26.0200 ( -26.02 49.2376 )
Norm@50keV : 36.6690 ( -1.95837 431663 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.26 using 59 PHA bins.
# Reduced chi-squared = 0.8047 for 55 degrees of freedom
# Null hypothesis probability = 8.496875e-01
Photon flux (15-150 keV) in 261.4 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] : 17.7924 ( )
R^2/D10^2 : 1.11887E-02 ( )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 137.84 using 59 PHA bins.
# Reduced chi-squared = 2.4182 for 57 degrees of freedom
# Null hypothesis probability = 1.199784e-08
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.861e-07 2.005e-08
25- 50 8.530e-07 6.261e-08
50-150 1.954e-06 2.060e-07
15-150 2.993e-06 2.130e-07
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 ( )
Norm : 0.699814 (-0.037942 0.0379419)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 72.40 using 59 PHA bins.
# Reduced chi-squared = 1.270 for 57 degrees of freedom
# Null hypothesis probability = 8.215172e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.555e-07 2.915e-08
25- 50 8.763e-07 5.881e-08
50-150 1.922e-06 3.708e-07
15-150 3.254e-06 5.038e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 6.89858 (-0.970542 1.12263)
R1^2/D10^2 : 0.170889 (-0.0687698 0.122277)
kT2 [keV] : 32.4677 (-5.06039 7.79415)
R2^2/D10^2 : 1.39807E-03 (-0.000654831 0.00097961)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 38.42 using 59 PHA bins.
# Reduced chi-squared = 0.6986 for 55 degrees of freedom
# Null hypothesis probability = 9.563396e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.936e-07 7.933e-08
25- 50 8.125e-07 1.405e-07
50-150 2.693e-06 6.262e-07
15-150 3.900e-06 7.221e-07
Peak spectrum fit
Power-law model
Time interval is from 229.532 sec. to 230.532 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.01922 ( -0.15769 0.156901 )
Norm@50keV : 2.11402E-02 ( -0.00201262 0.00201054 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 65.11 using 59 PHA bins.
# Reduced chi-squared = 1.142 for 57 degrees of freedom
# Null hypothesis probability = 2.153760e-01
Photon flux (15-150 keV) in 1 sec: 2.43653 ( -0.230417 0.230417 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.27074e-07 ( -2.58522e-08 2.62059e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 229.532 sec. to 230.532 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.189761 ( -0.800726 0.675238 )
Epeak [keV] : 110.696 ( -32.3483 233.454 )
Norm@50keV : 5.49951E-02 ( -0.0292745 0.0794022 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.58 using 59 PHA bins.
# Reduced chi-squared = 1.082 for 56 degrees of freedom
# Null hypothesis probability = 3.140234e-01
Photon flux (15-150 keV) in 1 sec: 2.36047 ( -0.23958 0.23913 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.10495e-07 ( -2.9265e-08 2.9645e-08 ) ergs/cm2
Band function
Time interval is from 229.532 sec. to 230.532 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 5.00000 ( -5 -5 )
beta : -1.17416 ( -0.27504 0.193039 )
Epeak [keV] : 30.5208 ( -8.03453 6.47599 )
Norm@50keV : 485.535 ( -45.5771 2287.84 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.60 using 59 PHA bins.
# Reduced chi-squared = 1.102 for 55 degrees of freedom
# Null hypothesis probability = 2.808967e-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] : 18.4877 (-2.08028 2.43431)
R^2/D10^2 : 0.153096 (-0.0492924 0.0696841)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 69.71 using 59 PHA bins.
# Reduced chi-squared = 1.223 for 57 degrees of freedom
# Null hypothesis probability = 1.202642e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.039e-08 1.945e-09
25- 50 4.898e-08 6.410e-09
50-150 1.223e-07 2.416e-08
15-150 1.817e-07 2.515e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 ( )
Norm : 9.21824 (-0.907431 0.908651)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 89.33 using 59 PHA bins.
# Reduced chi-squared = 1.567 for 57 degrees of freedom
# Null hypothesis probability = 3.995019e-03
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.295e-08 1.265e-08
25- 50 4.414e-08 2.405e-08
50-150 9.681e-08 5.300e-08
15-150 1.639e-07 9.025e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 9.14789 (-4.1146 5.98911)
R1^2/D10^2 : 0.666292 (-0.435649 2.80981)
kT2 [keV] : 28.8403 (-8.38511 -28.8403)
R2^2/D10^2 : 2.91471E-02 (-0.027847 0.0719054)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.11 using 59 PHA bins.
# Reduced chi-squared = 1.093 for 55 degrees of freedom
# Null hypothesis probability = 2.960896e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.483e-08 8.000e-09
25- 50 4.743e-08 2.454e-08
50-150 1.500e-07 8.175e-08
15-150 2.123e-07 1.105e-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: 1.72935 ( -0.118321 0.120409 )
Norm@50keV : 2.69873E-03 ( -0.00018664 0.000184546 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.59 using 59 PHA bins.
# Reduced chi-squared = 1.133 for 57 degrees of freedom
# Null hypothesis probability = 2.285653e-01
Photon flux (15-150 keV) in 39.57 sec: 0.362176 ( -0.0226379 0.0226691 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.86634e-07 ( -7.12557e-08 7.20324e-08 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.72367 ( -0.434813 0.370824 )
Epeak [keV] : 9831.59 ( -9687.95 -9687.96 )
Norm@50keV : 2.70632E-03 ( -0.000682072 0.00185746 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.60 using 59 PHA bins.
# Reduced chi-squared = 1.153 for 56 degrees of freedom
# Null hypothesis probability = 2.014933e-01
Photon flux (15-150 keV) in 39.57 sec: 0.362020 ( -0.022621 0.022657 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.86583e-07 ( -8.20998e-08 7.14832e-08 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.118022 ( 1.22062 1.22062 )
beta : -1.77585 ( 1.75066 0.12918 )
Epeak [keV] : 29.2364 ( -28.6919 61.5768 )
Norm@50keV : 4.27316E-02 ( -0.045201 299.865 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 63.80 using 59 PHA bins.
# Reduced chi-squared = 1.160 for 55 degrees of freedom
# Null hypothesis probability = 1.945995e-01
Photon flux (15-150 keV) in 39.57 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) = 8.24e-07
S(50-100 keV) = 1.40e-06
T90 vs. Hardness ratio plot
T90 = 240.767999976873 sec.
Hardness ratio (energy fluence ratio) = 1.69903
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 1.4325
Count Ratio (50-100 keV) / (15-25 keV) = 1.34383
Mask shadow pattern
IMX = -2.310779479077750E-01, IMY = -2.923535457271975E-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:
-299.800000 -20.472000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
299.5818 35.2105 0.8 51.6 165.3 9.2903 14.2 0.7 Cyg X-1
308.1147 40.9975 2.0 44.8 173.0 1.8728 5.6 2.7 Cyg X-3
326.1436 38.3566 6.5 30.7 173.0 0.3567 1.8 2.5 Cyg X-2
359.4159 -5.9239 2.4 30.7 47.7 1.1585 4.7 357.1 UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-20.472000 19.100600
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
299.6361 35.0870 48.7 51.5 165.1 0.0527 0.2 7.2 Cyg X-1
308.1208 41.0614 4.9 44.8 173.1 -0.2966 -2.4 6.5 Cyg X-3
326.1587 38.3167 154.6 30.7 172.9 -0.0055 -0.1 0.7 Cyg X-2
337.4167 19.5606 0.4 20.4 128.3 1.9032 27.4 ------ UNKNOWN
6.1091 66.5873 2.5 42.0 -126.7 0.6231 4.6 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
66.100600 302.290000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
288.8596 10.8295 6.0 47.5 162.6 -3.4735 -1.9 7.8 GRS 1915+105
299.6010 35.2365 1.4 36.7 -161.0 6.1849 8.3 2.2 Cyg X-1
308.1386 41.0281 4.0 32.8 -147.0 2.0810 2.9 4.7 Cyg X-3
325.9803 38.3026 4.4 21.2 -129.7 1.4921 2.6 9.1 Cyg X-2
6.5315 -5.2145 2.6 37.9 23.8 4.4181 4.5 501.0 UNKNOWN
281.3532 15.1917 2.6 53.5 170.6 10.7746 4.5 ------ UNKNOWN
305.8956 19.3229 2.5 29.7 170.7 3.1133 4.7 ------ UNKNOWN
337.3932 19.5952 1.6 0.0 148.3 4.2012 7.2 ------ UNKNOWN
32.1608 4.2366 2.6 55.5 -5.5 10.2203 4.5 ------ UNKNOWN
16.8206 20.2964 2.7 37.0 -22.2 3.5331 4.4 ------ UNKNOWN
273.0364 36.8883 2.8 58.2 -162.2 11.8111 4.1 ------ UNKNOWN
Plot creation:
Sun May 31 15:58:33 EDT 2015