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
149.0462 13.6735 0.0159 23.4622 8.9239 1.3631972 12.091 TRIG_00553847
Foreground time interval of the image:
-12.499 73.301 (delta_t = 85.800 [sec])
Background time interval of the image:
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 64.000000
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 64.000000
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 64.000000
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)
The mask-weighted light curves based on cleaned DPHs
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 -40.172 sec. to 272.972 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.06689 ( -0.165508 0.173933 )
Norm@50keV : 6.11414E-04 ( -7.08451e-05 6.95453e-05 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.53 using 59 PHA bins.
# Reduced chi-squared = 1.097 for 57 degrees of freedom
# Null hypothesis probability = 2.862826e-01
Photon flux (15-150 keV) in 313.1 sec: 9.46490E-02 ( -0.00817085 0.00817202 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.77335e-06 ( -1.86051e-07 1.90095e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -40.172 sec. to 272.972 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.29544 ( -1.00415 0.697811 )
Epeak [keV] : 36.0581 ( -35.1692 15.9153 )
Norm@50keV : 1.76013E-03 ( -0.00109162 0.00534216 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.76 using 59 PHA bins.
# Reduced chi-squared = 1.067 for 56 degrees of freedom
# Null hypothesis probability = 3.406588e-01
Photon flux (15-150 keV) in 313.1 sec: 9.16265E-02 ( -0.0087058 0.0087085 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.62312e-06 ( -2.19283e-07 2.39932e-07 ) ergs/cm2
Band function
Time interval is from -40.172 sec. to 272.972 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.29608 ( 1.89921 0.365158 )
beta : -10.00000 ( 10 1.42109e-14 )
Epeak [keV] : 36.0536 ( -8.02713 11.9859 )
Norm@50keV : 1.75823E-03 ( -0.000150889 0.00535132 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.76 using 59 PHA bins.
# Reduced chi-squared = 1.087 for 55 degrees of freedom
# Null hypothesis probability = 3.068229e-01
Photon flux (15-150 keV) in 313.1 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 1.65373e-06 ( 0 0 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 9.33072 (-0.856115 0.945239)
R^2/D10^2 : 5.69526E-02 (-0.0178884 0.0260008)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 75.07 using 59 PHA bins.
# Reduced chi-squared = 1.317 for 57 degrees of freedom
# Null hypothesis probability = 5.464831e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.076e-07 4.612e-08
25- 50 6.911e-07 7.561e-08
50-150 2.941e-07 7.809e-08
15-150 1.293e-06 1.354e-07
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 56.7434 (-13.0757 19.1879)
Norm : 0.507325 (-0.0733716 0.0838751)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.74 using 59 PHA bins.
# Reduced chi-squared = 1.048 for 57 degrees of freedom
# Null hypothesis probability = 3.765229e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.954e-07 4.728e-08
25- 50 5.913e-07 6.184e-08
50-150 6.417e-07 1.625e-07
15-150 1.628e-06 2.189e-07
Double BB
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 7.55360 ( )
R1^2/D10^2 : 0.110015 (-0.050194 25.2491)
kT2 [keV] : 29.5190 (-19.6714 -29.623)
R2^2/D10^2 : 3.60369E-04 (-0.000336026 0.0491188)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.53 using 59 PHA bins.
#Fit statistic : Chi-Squared = 62.04 using 59 PHA bins.
# Reduced chi-squared = 1.137 for 55 degrees of freedom
# Reduced chi-squared = 1.128 for 55 degrees of freedom
# Null hypothesis probability = 2.263642e-01
# Null hypothesis probability = 2.397374e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.912e-07 1.993e-07
25- 50 6.052e-07 2.376e-07
50-150 4.728e-07 2.234e-07
15-150 1.469e-06 6.182e-07
Peak spectrum fit
Power-law model
Time interval is from -37.676 sec. to -36.676 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.56949 ( -0.558766 0.733163 )
Norm@50keV : 3.28866E-03 ( -0.00165737 0.00172448 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.17 using 59 PHA bins.
# Reduced chi-squared = 1.126 for 57 degrees of freedom
# Null hypothesis probability = 2.397810e-01
Photon flux (15-150 keV) in 1 sec: 0.674511 ( -0.212472 0.213505 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.34956e-08 ( -1.247e-08 1.37559e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -37.676 sec. to -36.676 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.48739 ( -7.36018 3.27498 )
Epeak [keV] : 30.0417 ( )
Norm@50keV : 1.28321 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.47 using 59 PHA bins.
# Reduced chi-squared = 1.062 for 56 degrees of freedom
# Null hypothesis probability = 3.503472e-01
Photon flux (15-150 keV) in 1 sec: 0.656373 ( -0.203429 0.204725 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.02599e-08 ( -9.5714e-09 1.06704e-08 ) ergs/cm2
Band function
Time interval is from -37.676 sec. to -36.676 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 1.96407 ( -2.63643 -1.50158 )
beta : -10.0000 ( 10 3.55271e-15 )
Epeak [keV] : 30.5691 ( -14.4832 8.26331 )
Norm@50keV : 2.54107 ( -2.67066 316.051 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.44 using 59 PHA bins.
# Reduced chi-squared = 1.081 for 55 degrees of freedom
# Null hypothesis probability = 3.172651e-01
Photon flux (15-150 keV) in 1 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 3.09465e-08 ( 0 0 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 7.75958 (-1.83329 2.21193)
R^2/D10^2 : 0.940313 (-0.940279 1.86444)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.41 using 59 PHA bins.
# Reduced chi-squared = 1.042 for 57 degrees of freedom
# Null hypothesis probability = 3.879148e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 9.999e-09 6.050e-09
25- 50 1.659e-08 9.995e-09
50-150 3.935e-09 3.179e-09
15-150 3.052e-08 1.918e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 28.9501 (-12.9513 27.4252)
Norm : 5.85671 (-2.59205 4.94991)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.57 using 59 PHA bins.
# Reduced chi-squared = 1.080 for 57 degrees of freedom
# Null hypothesis probability = 3.160421e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.170e-08 7.205e-09
25- 50 1.310e-08 7.859e-09
50-150 6.845e-09 5.909e-09
15-150 3.165e-08 2.003e-08
Double BB
R1^2/D10^2 : 5.13841E+05 ( )
kT2 [keV] : 8.01916 (-1.91287 2.41103)
R2^2/D10^2 : 0.797983 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.35 using 59 PHA bins.
#Fit statistic : Chi-Squared = 58.92 using 59 PHA bins.
#Fit statistic : Chi-Squared = 58.89 using 59 PHA bins.
# Reduced chi-squared = 1.079 for 55 degrees of freedom
# Reduced chi-squared = 1.071 for 55 degrees of freedom
# Reduced chi-squared = 1.071 for 55 degrees of freedom
# Null hypothesis probability = 3.200940e-01
# Null hypothesis probability = 3.341389e-01
# Null hypothesis probability = 3.352782e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.029e-08 6.395e-09
25- 50 1.642e-08 1.025e-08
50-150 3.981e-09 2.993e-09
15-150 3.069e-08 1.910e-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: 2.16828 ( -0.240454 0.262313 )
Norm@50keV : 7.14650E-04 ( -0.000136279 0.000134101 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 68.68 using 59 PHA bins.
# Reduced chi-squared = 1.205 for 57 degrees of freedom
# Null hypothesis probability = 1.381200e-01
Photon flux (15-150 keV) in 85.8 sec: 0.116374 ( -0.0154155 0.015419 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.74047e-07 ( -9.44933e-08 9.83054e-08 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.198905 ( -1.80766 1.32 )
Epeak [keV] : 33.9948 ( -9.55013 6.33096 )
Norm@50keV : 1.17518E-02 ( -0.0121175 0.155333 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.29 using 59 PHA bins.
# Reduced chi-squared = 1.095 for 56 degrees of freedom
# Null hypothesis probability = 2.918665e-01
Photon flux (15-150 keV) in 85.8 sec: 0.111382 ( -0.0153005 0.015411 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.92863e-07 ( -8.293e-08 9.65988e-08 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.133386 ( -1.52441 1.55057 )
beta : -9.97501 ( 9.89805 19.898 )
Epeak [keV] : 33.9225 ( -5.90432 7.47373 )
Norm@50keV : 1.29818E-02 ( -0.00168164 0.827972 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.30 using 59 PHA bins.
# Reduced chi-squared = 1.115 for 55 degrees of freedom
# Null hypothesis probability = 2.604245e-01
Photon flux (15-150 keV) in 85.8 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) = 5.44e-07
S(50-100 keV) = 5.19e-07
T90 vs. Hardness ratio plot
T90 = 274.923999965191 sec.
Hardness ratio (energy fluence ratio) = 0.954044
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 1.19383
Count Ratio (50-100 keV) / (15-25 keV) = 0.417153
Mask shadow pattern
IMX = 4.287745920250035E-01, IMY = -6.732734992307260E-02
TIME vs. PHA plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 64.000000
TIME vs. DetID plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 64.000000
100 us light curve (15-350 keV)
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 64.000000
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:
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-12.499400 73.300640
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
135.5463 -40.4666 21.7 32.7 173.3 0.0726 0.5 5.3 Vela X-1
166.4303 8.2186 2.5 30.8 45.5 0.7249 4.5 ------ UNKNOWN
151.3353 -36.7568 2.1 30.4 148.9 0.7712 5.5 ------ UNKNOWN
149.0462 13.6735 1.0 23.5 8.9 1.3635 12.1 ------ UNKNOWN
125.5357 -49.0590 2.5 42.8 -179.1 0.8027 4.6 ------ UNKNOWN
140.8554 33.3967 2.1 41.5 -12.3 0.8435 5.5 ------ UNKNOWN
111.9364 -48.7412 2.3 47.1 -168.0 1.0332 5.0 ------ UNKNOWN
118.4669 -31.8436 3.1 31.2 -155.9 0.4318 3.7 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
118.900600 353.900600
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
135.5180 -40.3947 9.7 55.5 172.2 1.3643 1.3 9.6 Vela X-1
151.6856 -33.8839 2.1 47.6 156.7 3.5804 5.5 ------ UNKNOWN
175.5517 25.1485 2.6 27.4 41.0 1.0712 4.5 ------ UNKNOWN
140.9335 -13.0569 3.2 27.9 176.8 0.7285 3.7 ------ UNKNOWN
149.0096 13.6880 1.9 0.0 -66.8 1.0519 6.0 ------ UNKNOWN
108.4854 -30.3136 3.7 58.8 -159.3 4.6528 3.1 ------ UNKNOWN
111.3081 49.5002 3.7 47.3 -53.0 3.1853 3.1 ------ UNKNOWN
Plot creation:
Sat May 30 17:10:34 EDT 2015