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
273.9765 -52.1243 0.0146 43.7996 19.6862 0.9560139 13.229 TRIG_00531003
Foreground time interval of the image:
-0.244 11.968 (delta_t = 12.212 [sec])
Background time interval of the image:
-239.320 -0.244 (delta_t = 239.076 [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)
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 -0.244 sec. to 11.968 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.30031 ( -0.218651 0.236915 )
Norm@50keV : 4.21300E-03 ( -0.000710565 0.000696567 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.81 using 59 PHA bins.
# Reduced chi-squared = 0.9440 for 57 degrees of freedom
# Null hypothesis probability = 5.955690e-01
Photon flux (15-150 keV) in 12.21 sec: 0.736386 ( -0.0864554 0.0864704 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.91603e-07 ( -6.81728e-08 6.98174e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.244 sec. to 11.968 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.18406 ( -1.38404 0.766736 )
Epeak [keV] : 27.2523 ( )
Norm@50keV : 2.06925E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.29 using 59 PHA bins.
# Reduced chi-squared = 0.8981 for 56 degrees of freedom
# Null hypothesis probability = 6.898097e-01
Photon flux (15-150 keV) in 12.21 sec: 0.715881 ( -0.087903 0.088242 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.4619e-07 ( -7.10537e-08 7.88949e-08 ) ergs/cm2
Band function
Time interval is from -0.244 sec. to 11.968 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 4.72877 ( -6.54024 -4.72877 )
beta : -2.60625 ( -0.40382 0.315708 )
Epeak [keV] : 22.9768 ( -3.57587 3.50397 )
Norm@50keV : 996.473 ( -115.274 6368.42 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 48.50 using 59 PHA bins.
# Reduced chi-squared = 0.8817 for 55 degrees of freedom
# Null hypothesis probability = 7.197592e-01
Photon flux (15-150 keV) in 12.21 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 4.67581e-07 ( -4.67495e-07 -7.10305e-08 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 8.04255 (-1.05495 1.19717)
R^2/D10^2 : 0.798027 (-0.34233 0.616303)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.02 using 59 PHA bins.
# Reduced chi-squared = 1.035 for 57 degrees of freedom
# Null hypothesis probability = 4.016560e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.144e-07 2.325e-08
25- 50 2.021e-07 3.278e-08
50-150 5.400e-08 2.130e-08
15-150 3.705e-07 5.904e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 40.6278 (-10.2562 15.4911)
Norm : 4.75637 (-0.97602 1.28433)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.30 using 59 PHA bins.
# Reduced chi-squared = 0.8825 for 57 degrees of freedom
# Null hypothesis probability = 7.226819e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.341e-07 1.982e-08
25- 50 1.775e-07 2.473e-08
50-150 1.397e-07 5.344e-08
15-150 4.513e-07 7.821e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 5.45254 (-1.71091 1.83872)
R1^2/D10^2 : 2.79211 (-1.73084 2.89401)
kT2 [keV] : 15.4272 (-5.25502 19.6842)
R2^2/D10^2 : 3.30354E-02 (-0.0314518 0.221864)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.04 using 59 PHA bins.
# Reduced chi-squared = 0.8916 for 55 degrees of freedom
# Null hypothesis probability = 7.005729e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.358e-07 7.350e-08
25- 50 1.746e-07 8.926e-08
50-150 1.393e-07 8.162e-08
15-150 4.498e-07 2.297e-07
Peak spectrum fit
Power-law model
Time interval is from 0.172 sec. to 1.172 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.93336 ( -0.240784 0.253409 )
Norm@50keV : 1.52874E-02 ( -0.00255767 0.00250011 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.72 using 59 PHA bins.
# Reduced chi-squared = 1.083 for 57 degrees of freedom
# Null hypothesis probability = 3.112799e-01
Photon flux (15-150 keV) in 1 sec: 2.22564 ( -0.32338 0.323739 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.40621e-07 ( -2.26457e-08 2.29957e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.172 sec. to 1.172 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.19404 ( -1.30851 0.890594 )
Epeak [keV] : 46.0800 ( )
Norm@50keV : 4.08450E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.19 using 59 PHA bins.
# Reduced chi-squared = 1.075 for 56 degrees of freedom
# Null hypothesis probability = 3.265274e-01
Photon flux (15-150 keV) in 1 sec: 2.18326 ( -0.32886 0.32904 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.32021e-07 ( -2.4917e-08 2.5874e-08 ) ergs/cm2
Band function
Time interval is from 0.172 sec. to 1.172 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 5.00000 ( -4.82602 -5 )
beta : -2.23748 ( -0.409005 0.330522 )
Epeak [keV] : 25.2662 ( -4.55117 4.00701 )
Norm@50keV : 2370.62 ( -332.169 6219.56 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.52 using 59 PHA bins.
# Reduced chi-squared = 1.010 for 55 degrees of freedom
# Null hypothesis probability = 4.548699e-01
Photon flux (15-150 keV) in 1 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 1.35624e-07 ( -1.35617e-07 -2.2893e-08 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 10.2598 (-1.7276 2.02421)
R^2/D10^2 : 0.962995 (-0.482081 0.996109)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 69.42 using 59 PHA bins.
# Reduced chi-squared = 1.218 for 57 degrees of freedom
# Null hypothesis probability = 1.251646e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.082e-08 5.245e-09
25- 50 5.364e-08 1.089e-08
50-150 3.014e-08 1.074e-08
15-150 1.046e-07 1.967e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 73.3567 (-25.3723 51.2225)
Norm : 10.8797 (-2.23787 2.82082)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.17 using 59 PHA bins.
# Reduced chi-squared = 1.056 for 57 degrees of freedom
# Null hypothesis probability = 3.618983e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.804e-08 5.235e-09
25- 50 4.517e-08 8.105e-09
50-150 6.004e-08 2.492e-08
15-150 1.333e-07 3.298e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 6.25884 (-1.81907 2.49702)
R1^2/D10^2 : 4.66019 (-3.16348 11.0659)
kT2 [keV] : 21.1043 (-7.50589 45.7791)
R2^2/D10^2 : 3.97185E-02 (-0.0386927 0.0801458)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.09 using 59 PHA bins.
# Reduced chi-squared = 1.056 for 55 degrees of freedom
# Null hypothesis probability = 3.620920e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.904e-08 1.588e-08
25- 50 4.527e-08 2.344e-08
50-150 6.015e-08 3.299e-08
15-150 1.345e-07 7.010e-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: 2.30031 ( -0.218651 0.236915 )
Norm@50keV : 4.21300E-03 ( -0.000710565 0.000696567 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.81 using 59 PHA bins.
# Reduced chi-squared = 0.9440 for 57 degrees of freedom
# Null hypothesis probability = 5.955690e-01
Photon flux (15-150 keV) in 12.21 sec: 0.736386 ( -0.0864554 0.0864704 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.91603e-07 ( -6.81728e-08 6.98174e-08 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.18406 ( -1.38404 0.766736 )
Epeak [keV] : 27.2523 ( )
Norm@50keV : 2.06925E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.29 using 59 PHA bins.
# Reduced chi-squared = 0.8981 for 56 degrees of freedom
# Null hypothesis probability = 6.898097e-01
Photon flux (15-150 keV) in 12.21 sec: 0.715881 ( -0.087903 0.088242 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.4619e-07 ( -7.10537e-08 7.88949e-08 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 4.72877 ( -6.53805 -4.72877 )
beta : -2.60625 ( -0.40382 0.315708 )
Epeak [keV] : 22.9768 ( -3.57587 3.50397 )
Norm@50keV : 996.473 ( -115.274 6368.42 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 48.50 using 59 PHA bins.
# Reduced chi-squared = 0.8817 for 55 degrees of freedom
# Null hypothesis probability = 7.197592e-01
Photon flux (15-150 keV) in 12.21 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 4.67581e-07 ( -4.67495e-07 -7.10305e-08 ) ergs/cm2
S(25-50 keV) vs. S(50-100 keV) plot
S(25-50 keV) = 1.59e-07
S(50-100 keV) = 1.29e-07
T90 vs. Hardness ratio plot
T90 = 7.23199999332428 sec.
Hardness ratio (energy fluence ratio) = 0.811321
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 1.01518
Count Ratio (50-100 keV) / (15-25 keV) = 0.369917
Mask shadow pattern
IMX = 9.029025794022019E-01, IMY = -3.230404159963384E-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:
-239.320000 -0.244000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
170.4218 -60.6537 124.6 46.0 -56.8 -0.0776 -0.1 3.6 Cen X-3
186.3053 -62.7157 5.9 44.8 -46.0 1.0665 2.0 10.2 GX 301-2
264.6080 -44.3913 6.5 53.4 16.1 1.4030 1.8 6.8 4U 1735-44
260.0368 -43.1046 2.8 55.7 12.8 4.0365 4.1 ------ UNKNOWN
273.2647 -59.8847 2.4 37.1 13.6 1.2210 4.9 ------ UNKNOWN
328.8991 -69.9008 3.1 14.3 36.7 0.5984 3.7 ------ UNKNOWN
43.1326 -40.7110 2.6 34.8 179.8 0.9479 4.5 ------ UNKNOWN
101.8941 -49.3889 2.0 43.2 -113.2 4.5028 5.6 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-0.244000 11.968000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
170.5468 -60.7354 5.0 46.0 -56.7 0.3159 2.3 9.6 Cen X-3
186.2570 -62.7881 32.6 44.7 -46.0 -0.0296 -0.4 11.0 GX 301-2
264.5992 -44.3410 5.4 53.4 16.1 -0.3297 -2.1 9.0 4U 1735-44
273.9765 -52.1243 0.9 43.8 19.7 0.9562 13.2 ------ UNKNOWN
344.5032 -81.7927 2.4 11.1 -20.4 0.1471 4.9 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
523.080610 962.777700
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
135.5753 -40.5405 1.9 28.1 174.3 2.1105 6.2 2.3 Vela X-1
170.4669 -60.6050 4.7 27.8 109.1 -1.0645 -2.4 4.6 Cen X-3
186.7557 -62.7909 8.8 31.9 95.2 0.7071 1.3 3.0 GX 301-2
208.4396 12.9207 3.4 58.9 -24.4 8.0946 3.4 ------ UNKNOWN
Plot creation:
Sat May 30 18:43:11 EDT 2015