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
152.3052 -26.6474 0.0054 34.0680 -175.1568 1.7368904 35.592 TRIG_00638946
Foreground time interval of the image:
-0.060 9.137 (delta_t = 9.197 [sec])
Background time interval of the image:
-239.564 -0.060 (delta_t = 239.504 [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 -0.060 sec. to 95.012 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.17156 ( -0.152602 0.149173 )
Norm@50keV : 1.53899E-03 ( -0.000126803 0.000126385 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.85 using 59 PHA bins.
# Reduced chi-squared = 1.085 for 57 degrees of freedom
# Null hypothesis probability = 3.070241e-01
Photon flux (15-150 keV) in 95.07 sec: 0.179957 ( -0.0155706 0.0156588 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.4966e-06 ( -1.31579e-07 1.32055e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.060 sec. to 95.012 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.16699 ( -0.334285 0.202061 )
Epeak [keV] : 1.00000E+04 ( )
Norm@50keV : 1.54658E-03 ( -0.000126215 0.000125975 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.88 using 59 PHA bins.
# Reduced chi-squared = 1.105 for 56 degrees of freedom
# Null hypothesis probability = 2.743960e-01
Photon flux (15-150 keV) in 95.07 sec: 0.180035 ( -0.015655 0.015494 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.49299e-06 ( -1.27926e-07 1.36197e-07 ) ergs/cm2
Band function
Time interval is from -0.060 sec. to 95.012 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 4.81278 ( -4.81278 -4.81278 )
beta : -1.18901 ( -0.158639 0.158067 )
Epeak [keV] : 21.4694 ( -21.4694 8.47686 )
Norm@50keV : 213.646 ( -17.4072 406961 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.68 using 59 PHA bins.
# Reduced chi-squared = 1.121 for 55 degrees of freedom
# Null hypothesis probability = 2.496669e-01
Photon flux (15-150 keV) in 95.07 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] : 21.0963 (-2.48908 2.96997)
R^2/D10^2 : 6.81423E-03 (-0.00236151 0.00348094)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 104.24 using 59 PHA bins.
# Reduced chi-squared = 1.8288 for 57 degrees of freedom
# Null hypothesis probability = 1.356462e-04
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 5.436e-08 9.935e-09
25- 50 2.802e-07 3.950e-08
50-150 9.299e-07 1.300e-07
15-150 1.265e-06 1.340e-07
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 ( )
Norm : 0.756977 (-0.0633426 0.0633315)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 82.50 using 59 PHA bins.
# Reduced chi-squared = 1.447 for 57 degrees of freedom
# Null hypothesis probability = 1.524951e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.793e-07 1.901e-08
25- 50 3.448e-07 6.417e-08
50-150 7.563e-07 3.164e-07
15-150 1.280e-06 3.628e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 7.33219 (-1.69354 2.3453)
R1^2/D10^2 : 0.145880 (-0.0873579 0.228997)
kT2 [keV] : 36.8598 (-8.45652 20.6537)
R2^2/D10^2 : 1.03556E-03 (-0.000725845 0.0012931)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.96 using 59 PHA bins.
# Reduced chi-squared = 1.108 for 55 degrees of freedom
# Null hypothesis probability = 2.702203e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.437e-07 5.645e-08
25- 50 3.091e-07 1.024e-07
50-150 1.083e-06 3.962e-07
15-150 1.536e-06 5.450e-07
Peak spectrum fit
Power-law model
Time interval is from -0.072 sec. to 0.928 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.802818 ( -0.062327 0.0617769 )
Norm@50keV : 0.104953 ( -0.00368044 0.00366314 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.54 using 59 PHA bins.
# Reduced chi-squared = 0.8691 for 57 degrees of freedom
# Null hypothesis probability = 7.481738e-01
Photon flux (15-150 keV) in 1 sec: 12.0612 ( -0.414943 0.41531 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.22501e-06 ( -4.55728e-08 4.56843e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.072 sec. to 0.928 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.795134 ( -0.0626146 0.0624962 )
Epeak [keV] : 9999.06 ( -9999 -9999 )
Norm@50keV : 0.105708 ( -0.00364058 0.0296961 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.53 using 59 PHA bins.
# Reduced chi-squared = 0.8844 for 56 degrees of freedom
# Null hypothesis probability = 7.167891e-01
Photon flux (15-150 keV) in 1 sec: 12.0579 ( -0.4322 0.3237 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.22787e-06 ( 0 0 ) ergs/cm2
Band function
Time interval is from -0.072 sec. to 0.928 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.909223 ( 0.909223 0.909223 )
beta : -0.802818 ( -0.0617624 0.0623528 )
Epeak [keV] : 13.5927 ( -13.5927 -13.5927 )
Norm@50keV : 0.155662 ( -0.0492149 1.42956e+06 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.54 using 59 PHA bins.
# Reduced chi-squared = 0.9007 for 55 degrees of freedom
# Null hypothesis probability = 6.825869e-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] : 25.7422 ( )
R^2/D10^2 : 0.281508 ( )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 174.72 using 59 PHA bins.
# Reduced chi-squared = 3.0653 for 57 degrees of freedom
# Null hypothesis probability = 7.055066e-14
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.190e-08 2.190e-09
25- 50 1.837e-07 9.400e-09
50-150 8.982e-07 4.365e-08
15-150 1.114e-06 4.900e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 199.363 ( )
Norm : 46.6713 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 429.46 using 59 PHA bins.
# Reduced chi-squared = 7.5343 for 57 degrees of freedom
# Null hypothesis probability = 1.486360e-58
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.162e-07 4.150e-09
25- 50 2.236e-07 8.800e-09
50-150 4.903e-07 1.790e-08
15-150 8.301e-07 3.260e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 9.63718 (-2.17274 2.69622)
R1^2/D10^2 : 2.67055 (-1.21473 2.93688)
kT2 [keV] : 43.3965 (-7.73782 18.3739)
R2^2/D10^2 : 5.42902E-02 (-0.0327122 0.0426703)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.45 using 59 PHA bins.
# Reduced chi-squared = 1.063 for 55 degrees of freedom
# Null hypothesis probability = 3.498279e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 6.226e-08 8.030e-09
25- 50 2.042e-07 2.355e-08
50-150 9.681e-07 1.276e-07
15-150 1.235e-06 1.497e-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: 0.866269 ( -0.0915471 0.0896495 )
Norm@50keV : 1.20181E-02 ( -0.000616037 0.000611315 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.17 using 59 PHA bins.
# Reduced chi-squared = 0.8275 for 57 degrees of freedom
# Null hypothesis probability = 8.202317e-01
Photon flux (15-150 keV) in 9.197 sec: 1.37935 ( -0.0699434 0.0702664 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.25705e-06 ( -6.29685e-08 6.31265e-08 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.862868 ( -0.0954697 0.0873644 )
Epeak [keV] : 9999.36 ( -9999.36 -9999.36 )
Norm@50keV : 1.20971E-02 ( -0.000624323 0.00262173 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.23 using 59 PHA bins.
# Reduced chi-squared = 0.8435 for 56 degrees of freedom
# Null hypothesis probability = 7.915924e-01
Photon flux (15-150 keV) in 9.197 sec: 1.37979 ( -0.0709 0.06936 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.2567e-06 ( -6.21441e-08 6.29259e-08 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.808287 ( 0.808224 0.808224 )
beta : -0.866269 ( -0.0896134 0.0916247 )
Epeak [keV] : 14.1862 ( -14.1869 -14.1869 )
Norm@50keV : 1.81569E-02 ( -0.00673019 0 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.17 using 59 PHA bins.
# Reduced chi-squared = 0.8576 for 55 degrees of freedom
# Null hypothesis probability = 7.645111e-01
Photon flux (15-150 keV) in 9.197 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) = 3.09e-07
S(50-100 keV) = 5.49e-07
T90 vs. Hardness ratio plot
T90 = 81.055999994278 sec.
Hardness ratio (energy fluence ratio) = 1.7767
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 1.58833
Count Ratio (50-100 keV) / (15-25 keV) = 1.76558
Mask shadow pattern
IMX = -6.738218905893313E-01, IMY = 5.709394877316486E-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:
-239.564000 -0.060000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
135.5888 -40.6384 5.1 53.7 -175.0 1.4619 2.3 5.7 Vela X-1
201.3187 -30.4920 3.9 41.0 111.8 2.4750 2.9 ------ UNKNOWN
121.7342 -32.1863 3.5 58.8 -159.3 4.8241 3.3 ------ UNKNOWN
189.6613 58.5217 2.3 59.2 -20.4 6.2319 4.9 ------ UNKNOWN
130.4924 -16.6153 2.6 45.7 -144.5 1.8881 4.4 ------ UNKNOWN
147.0256 31.9921 3.1 40.0 -66.1 2.1285 3.7 ------ UNKNOWN
129.5737 3.0681 2.7 43.8 -116.5 3.5777 4.3 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-0.060000 9.136600
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
135.4894 -40.4525 8.2 53.7 -174.7 0.1706 1.4 6.4 Vela X-1
152.3052 -26.6474 0.3 34.1 -175.2 1.7369 35.6 ------ UNKNOWN
131.1279 -37.3112 2.4 54.5 -169.1 0.6473 4.9 ------ UNKNOWN
176.6153 52.2707 2.0 51.6 -27.7 0.6781 5.9 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
75.536620 962.566000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
135.5272 -40.5526 1.7 19.7 -137.4 3.9709 6.8 0.1 Vela X-1
170.3862 -60.6351 4.4 36.2 167.0 2.2742 2.6 2.2 Cen X-3
186.6944 -62.7769 0.8 42.6 159.5 17.8632 13.7 1.1 GX 301-2
175.5856 19.0359 3.9 50.9 30.7 8.4977 3.0 ------ UNKNOWN
161.1524 -44.2019 2.8 19.0 162.1 2.2895 4.2 ------ UNKNOWN
101.4962 -38.0470 3.9 43.9 -116.3 7.7909 3.0 ------ UNKNOWN
Plot creation:
Thu May 28 12:57:41 EDT 2015