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
2.1639 -37.8770 0.0050 50.1980 -34.0831 8.9135016 38.677 TRIG_00451757
Foreground time interval of the image:
-0.104 10.989 (delta_t = 11.093 [sec])
Background time interval of the image:
-239.912 -0.104 (delta_t = 239.808 [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 -0.104 sec. to 21.816 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.27024 ( -0.0648655 0.0658492 )
Norm@50keV : 3.08648E-02 ( -0.00109266 0.0010864 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 42.92 using 59 PHA bins.
# Reduced chi-squared = 0.7530 for 57 degrees of freedom
# Null hypothesis probability = 9.165109e-01
Photon flux (15-150 keV) in 21.92 sec: 5.30605 ( -0.198921 0.200372 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.43115e-06 ( -2.05763e-07 2.05852e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.104 sec. to 21.816 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.99058 ( )
Epeak [keV] : 1.69146 ( -0.346674 18.577 )
Norm@50keV : 4.23606E-02 ( -0.0020974 0.00307436 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 42.37 using 59 PHA bins.
# Reduced chi-squared = 0.7566 for 56 degrees of freedom
# Null hypothesis probability = 9.108694e-01
Photon flux (15-150 keV) in 21.92 sec: 5.22884 ( -0.22879 0.22698 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.35371e-06 ( -2.40419e-07 2.38621e-07 ) ergs/cm2
Band function
Time interval is from -0.104 sec. to 21.816 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.94605 ( 1.87629 1.87629 )
beta : -2.32775 ( 2.32633 0.109033 )
Epeak [keV] : 6.37338 ( -6.15095 11.9366 )
Norm@50keV : 4.76110E-02 ( -0.00743948 0.217902 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 41.97 using 59 PHA bins.
# Reduced chi-squared = 0.7631 for 55 degrees of freedom
# Null hypothesis probability = 9.017809e-01
Photon flux (15-150 keV) in 21.92 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 6.34209e-06 ( 0 0 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 10.8411 ( )
R^2/D10^2 : 1.54451 ( )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 305.60 using 59 PHA bins.
# Reduced chi-squared = 5.3614 for 57 degrees of freedom
# Null hypothesis probability = 1.070517e-35
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 8.289e-07 5.096e-08
25- 50 2.300e-06 8.878e-08
50-150 1.510e-06 1.111e-07
15-150 4.638e-06 1.611e-07
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 56.3757 (-4.79525 5.40501)
Norm : 26.6483 (-1.73191 1.56051)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 63.63 using 59 PHA bins.
# Reduced chi-squared = 1.116 for 57 degrees of freedom
# Null hypothesis probability = 2.545214e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.452e-06 8.023e-08
25- 50 2.167e-06 8.209e-08
50-150 2.339e-06 1.502e-07
15-150 5.959e-06 1.995e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 5.67147 (-0.546365 0.58079)
R1^2/D10^2 : 16.2697 (-5.3436 8.89263)
kT2 [keV] : 19.5185 (-1.81778 2.27121)
R2^2/D10^2 : 0.106507 (-0.0397694 0.0561718)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.13 using 59 PHA bins.
# Reduced chi-squared = 0.9479 for 55 degrees of freedom
# Null hypothesis probability = 5.849009e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.572e-06 1.580e-07
25- 50 2.080e-06 1.345e-07
50-150 2.476e-06 2.327e-07
15-150 6.128e-06 4.099e-07
Peak spectrum fit
Power-law model
Time interval is from 8.044 sec. to 9.044 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.79720 ( -0.105164 0.106893 )
Norm@50keV : 0.103216 ( -0.00625877 0.00623383 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 37.25 using 59 PHA bins.
# Reduced chi-squared = 0.6534 for 57 degrees of freedom
# Null hypothesis probability = 9.801441e-01
Photon flux (15-150 keV) in 1 sec: 14.2075 ( -0.911349 0.914459 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.50303e-07 ( -5.84112e-08 5.85737e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 8.044 sec. to 9.044 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.01456 ( -2.01456 -2.01456 )
Epeak [keV] : 6.66160 ( )
Norm@50keV : 7.95025E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 36.57 using 59 PHA bins.
# Reduced chi-squared = 0.6530 for 56 degrees of freedom
# Null hypothesis probability = 9.793684e-01
Photon flux (15-150 keV) in 1 sec: 14.2373 ( -0.9496 0.8819 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.49887e-07 ( -5.7815e-08 5.8163e-08 ) ergs/cm2
Band function
Time interval is from 8.044 sec. to 9.044 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.46602 ( 1.48086 1.48086 )
beta : -1.79684 ( -0.106874 0.10512 )
Epeak [keV] : 23.4027 ( -20.3728 -20.3728 )
Norm@50keV : 0.216416 ( -0.0969442 14.6559 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 37.25 using 59 PHA bins.
# Reduced chi-squared = 0.6772 for 55 degrees of freedom
# Null hypothesis probability = 9.681106e-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] : 14.5301 ( )
R^2/D10^2 : 1.64124 ( )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 144.29 using 59 PHA bins.
# Reduced chi-squared = 2.5314 for 57 degrees of freedom
# Null hypothesis probability = 1.633006e-09
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 7.289e-08 9.050e-09
25- 50 2.811e-07 2.315e-08
50-150 3.980e-07 4.245e-08
15-150 7.520e-07 5.430e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 132.476 (-30.4104 36.8281)
Norm : 57.5202 (-4.35678 5.60425)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.38 using 59 PHA bins.
# Reduced chi-squared = 0.7785 for 57 degrees of freedom
# Null hypothesis probability = 8.886033e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.491e-07 1.385e-08
25- 50 2.711e-07 2.145e-08
50-150 5.071e-07 1.524e-07
15-150 9.273e-07 1.760e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 5.54157 (-1.05442 1.30184)
R1^2/D10^2 : 42.8270 (-23.8612 63.711)
kT2 [keV] : 23.6014 (-3.35812 5.26245)
R2^2/D10^2 : 0.221571 (-0.117646 0.182126)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.63 using 59 PHA bins.
# Reduced chi-squared = 0.8114 for 55 degrees of freedom
# Null hypothesis probability = 8.399722e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.766e-07 4.115e-08
25- 50 2.505e-07 3.720e-08
50-150 5.135e-07 7.860e-08
15-150 9.405e-07 1.320e-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: 2.23055 ( -0.0656687 0.0666144 )
Norm@50keV : 4.76618E-02 ( -0.00169332 0.00168429 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 41.45 using 59 PHA bins.
# Reduced chi-squared = 0.7273 for 57 degrees of freedom
# Null hypothesis probability = 9.394789e-01
Photon flux (15-150 keV) in 11.09 sec: 8.01949 ( -0.308466 0.310698 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.9921e-06 ( -1.62978e-07 1.63064e-07 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.98875 ( )
Epeak [keV] : 2.47458 ( -0.585118 16.0062 )
Norm@50keV : 6.19016E-02 ( -0.00441797 0.00455387 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.17 using 59 PHA bins.
# Reduced chi-squared = 0.7887 for 56 degrees of freedom
# Null hypothesis probability = 8.737133e-01
Photon flux (15-150 keV) in 11.09 sec: 8.02303 ( -0.17815 0.30107 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.99204e-06 ( -1.62036e-07 1.61659e-07 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.15970 ( )
beta : -9.37167 ( )
Epeak [keV] : 65.0901 ( )
Norm@50keV : 0.101634 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 154.02 using 59 PHA bins.
# Reduced chi-squared = 2.8003 for 55 degrees of freedom
# Null hypothesis probability = 2.561870e-11
Photon flux (15-150 keV) in 11.09 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) = 2.07e-06
S(50-100 keV) = 1.71e-06
T90 vs. Hardness ratio plot
T90 = 13.8679999709129 sec.
Hardness ratio (energy fluence ratio) = 0.826087
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 0.999872
Count Ratio (50-100 keV) / (15-25 keV) = 0.507883
Mask shadow pattern
IMX = 9.939953859145266E-01, IMY = 6.725578022923394E-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:
-239.912000 -0.104000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
268.3554 -1.4339 3.5 43.2 129.1 2.7231 3.3 1.4 SW J1753.5-0127
270.2372 -25.0575 8.8 36.6 93.2 0.7962 1.3 2.9 GX 5-1
270.3738 -25.8568 12.0 36.6 91.9 0.5926 1.0 7.8 GRS 1758-258
274.0373 -13.9885 2.0 33.8 112.8 2.2181 5.8 3.4 GX 17+2
276.1194 -30.4774 0.0 32.3 82.3 0.6564 1.6 12.0 H1820-303
285.0231 -24.8921 3.5 23.3 89.9 0.8799 3.3 1.8 HT1900.1-2455
288.8054 10.9494 1.3 35.2 165.1 2.5155 8.9 0.5 GRS 1915+105
299.6070 35.1648 2.1 53.9 -168.3 3.2537 5.6 2.4 Cyg X-1
308.2266 40.8413 13.3 58.9 -159.5 1.4504 0.9 8.5 Cyg X-3
316.6725 5.7813 3.2 25.0 -140.5 0.7255 3.6 ------ UNKNOWN
339.5783 12.6187 3.3 43.0 -112.1 3.5345 3.5 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-0.104000 10.988590
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
268.2247 -1.3754 0.0 43.4 129.1 -0.3188 -2.1 9.8 SW J1753.5-0127
270.1594 -25.2147 6.0 36.7 92.9 -0.2157 -1.9 10.6 GX 5-1
270.4015 -25.8395 18.2 36.5 91.9 0.0709 0.6 7.9 GRS 1758-258
273.9532 -14.1836 13.4 33.9 112.5 0.0732 0.9 9.3 GX 17+2
275.9504 -30.3519 59.8 32.4 82.6 -0.0148 -0.2 1.6 H1820-303
285.1589 -25.0372 6.0 23.2 89.5 -0.1096 -1.9 9.7 HT1900.1-2455
288.8043 10.7873 4.3 35.0 165.0 0.1598 2.7 9.5 GRS 1915+105
299.6196 35.3416 3.3 54.1 -168.3 0.3940 3.5 8.5 Cyg X-1
308.0616 40.9435 12.7 59.0 -159.6 -0.2166 -0.9 2.3 Cyg X-3
292.6422 -36.1985 2.7 23.2 56.4 0.2168 4.3 ------ UNKNOWN
306.7288 -0.1912 2.1 18.0 -166.3 0.2779 5.6 ------ UNKNOWN
314.4515 5.8463 2.7 24.5 -145.7 0.2386 4.3 ------ UNKNOWN
352.4674 -34.4243 2.7 41.9 -36.9 0.4733 4.3 ------ UNKNOWN
324.9207 14.9785 2.6 36.5 -132.4 0.4296 4.5 ------ UNKNOWN
2.1639 -37.8770 0.3 50.2 -34.1 8.9136 38.7 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
76.788600 962.158300
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
306.4456 -49.4310 2.2 40.9 113.9 9.8157 5.3 ------ UNKNOWN
68.4914 -43.3005 3.9 49.3 -2.7 2.9751 3.0 ------ UNKNOWN
50.1896 -13.2184 4.1 49.1 -48.0 7.1081 2.8 ------ UNKNOWN
Plot creation:
Sat May 30 22:27:26 EDT 2015