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
303.4871 34.3295 0.0114 44.9956 -15.7064 0.1468028 16.798 TRIG_00156838
Foreground time interval of the image:
-0.036 0.068 (delta_t = 0.104 [sec])
Background time interval of the image:
-299.376 -0.036 (delta_t = 299.340 [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 -0.036 sec. to 0.068 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.69462 ( -0.157896 0.165705 )
Norm@50keV : 7.75132E-02 ( -0.00912239 0.00906176 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 87.31 using 59 PHA bins.
# Reduced chi-squared = 1.532 for 57 degrees of freedom
# Null hypothesis probability = 6.023477e-03
Photon flux (15-150 keV) in 0.104 sec: 10.2752 ( -1.17787 1.17907 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.4673e-08 ( -9.0639e-09 9.08786e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.036 sec. to 0.068 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.110934 ( -0.94517 0.804274 )
Epeak [keV] : 63.8001 ( -8.01271 11.9385 )
Norm@50keV : 0.575344 ( -0.332743 0.98903 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 70.77 using 59 PHA bins.
# Reduced chi-squared = 1.264 for 56 degrees of freedom
# Null hypothesis probability = 8.842928e-02
Photon flux (15-150 keV) in 0.104 sec: 10.1455 ( -1.17833 1.1825 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.65087e-08 ( -9.25912e-09 9.29427e-09 ) ergs/cm2
Band function
Time interval is from -0.036 sec. to 0.068 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.112673 ( -0.765275 1.02274 )
beta : -10.0000 ( 10 1.77636e-15 )
Epeak [keV] : 63.7569 ( -7.98596 11.9898 )
Norm@50keV : 0.576826 ( -0.334159 0.989833 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 70.77 using 59 PHA bins.
# Reduced chi-squared = 1.287 for 55 degrees of freedom
# Null hypothesis probability = 7.463806e-02
Photon flux (15-150 keV) in 0.104 sec: 10.2505 ( -3.2505 -1.13968 ) 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] : 15.4884 (-1.54966 1.65332)
R^2/D10^2 : 1.18664 (-0.369243 0.537036)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 75.80 using 59 PHA bins.
# Reduced chi-squared = 1.330 for 57 degrees of freedom
# Null hypothesis probability = 4.857109e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 6.163e-09 1.119e-09
25- 50 2.521e-08 3.401e-09
50-150 4.173e-08 7.862e-09
15-150 7.310e-08 1.006e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 144.822 (-45.2573 -137.712)
Norm : 42.5427 (-5.41461 6.29253)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 80.08 using 59 PHA bins.
# Reduced chi-squared = 1.405 for 57 degrees of freedom
# Null hypothesis probability = 2.361233e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.140e-08 1.777e-09
25- 50 2.101e-08 5.356e-09
50-150 4.087e-08 2.024e-08
15-150 7.328e-08 2.176e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 2.38534 (-1.49354 4.92495)
R1^2/D10^2 : 1164.48 (-1197.07 1.45054e+07)
kT2 [keV] : 16.5784 (-1.87064 2.98839)
R2^2/D10^2 : 0.884825 (-0.470272 0.384429)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 67.50 using 59 PHA bins.
# Reduced chi-squared = 1.227 for 55 degrees of freedom
# Null hypothesis probability = 1.201864e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 9.876e-09 3.458e-09
25- 50 2.276e-08 4.207e-09
50-150 4.375e-08 8.549e-09
15-150 7.639e-08 1.207e-08
Peak spectrum fit
Power-law model
Time interval is from -0.482 sec. to 0.518 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.73306 ( -0.254822 0.268223 )
Norm@50keV : 1.10761E-02 ( -0.00198423 0.00195628 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.69 using 59 PHA bins.
# Reduced chi-squared = 0.8717 for 57 degrees of freedom
# Null hypothesis probability = 7.432809e-01
Photon flux (15-150 keV) in 1 sec: 1.48838 ( -0.247868 0.248317 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.02319e-07 ( -1.87138e-08 1.90145e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.482 sec. to 0.518 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 8.56650E-02 ( -1.60714 1.18194 )
Epeak [keV] : 55.0538 ( -11.4004 27.0858 )
Norm@50keV : 8.18886E-02 ( -0.0818875 0.488718 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 43.46 using 59 PHA bins.
# Reduced chi-squared = 0.7761 for 56 degrees of freedom
# Null hypothesis probability = 8.892872e-01
Photon flux (15-150 keV) in 1 sec: 1.42469 ( -0.25071 0.25186 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.45024e-08 ( -1.86922e-08 1.96356e-08 ) ergs/cm2
Band function
Time interval is from -0.482 sec. to 0.518 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -8.55185E-02 ( -1.40079 1.47436 )
beta : -10.0000 ( 10 1.06581e-14 )
Epeak [keV] : 55.0431 ( -11.4011 27.0906 )
Norm@50keV : 8.19132E-02 ( -0.0819127 0.491157 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 43.46 using 59 PHA bins.
# Reduced chi-squared = 0.7902 for 55 degrees of freedom
# Null hypothesis probability = 8.693781e-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] : 13.0665 (-2.1115 2.47812)
R^2/D10^2 : 0.285812 (-0.135676 0.255779)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 46.24 using 59 PHA bins.
# Reduced chi-squared = 0.8112 for 57 degrees of freedom
# Null hypothesis probability = 8.451752e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.035e-08 3.057e-09
25- 50 3.584e-08 1.052e-08
50-150 3.880e-08 1.263e-08
15-150 8.499e-08 2.064e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 116.060 (-47.0272 -111.87)
Norm : 6.39806 (-1.20163 1.64461)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 46.36 using 59 PHA bins.
# Reduced chi-squared = 0.8133 for 57 degrees of freedom
# Null hypothesis probability = 8.421409e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.669e-08 5.216e-09
25- 50 2.967e-08 1.209e-08
50-150 5.208e-08 3.443e-08
15-150 9.844e-08 5.265e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 6.39659 (-4.19945 24.3862)
R1^2/D10^2 : 1.61897 (-1.50584 126.121)
kT2 [keV] : 17.0877 (-4.60019 31.7016)
R2^2/D10^2 : 8.34193E-02 (-0.0834579 0.241253)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 43.02 using 59 PHA bins.
# Reduced chi-squared = 0.7821 for 55 degrees of freedom
# Null hypothesis probability = 8.796546e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.455e-08 8.175e-09
25- 50 3.297e-08 1.677e-08
50-150 4.725e-08 2.863e-08
15-150 9.477e-08 4.926e-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: 1.69462 ( -0.157896 0.165705 )
Norm@50keV : 7.75132E-02 ( -0.00912239 0.00906176 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 87.31 using 59 PHA bins.
# Reduced chi-squared = 1.532 for 57 degrees of freedom
# Null hypothesis probability = 6.023477e-03
Photon flux (15-150 keV) in 0.104 sec: 10.2752 ( -1.17787 1.17907 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.4673e-08 ( -9.0639e-09 9.08786e-09 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.110934 ( -0.94517 0.804274 )
Epeak [keV] : 63.8001 ( -8.01271 11.9385 )
Norm@50keV : 0.575344 ( -0.332743 0.98903 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 70.77 using 59 PHA bins.
# Reduced chi-squared = 1.264 for 56 degrees of freedom
# Null hypothesis probability = 8.842928e-02
Photon flux (15-150 keV) in 0.104 sec: 10.1455 ( -1.17833 1.1825 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.65087e-08 ( -9.25912e-09 9.29427e-09 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.112673 ( -0.765275 1.02274 )
beta : -10.0000 ( 10 3.55271e-15 )
Epeak [keV] : 63.7569 ( -7.98596 11.9898 )
Norm@50keV : 0.576826 ( -0.334159 0.989833 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 70.77 using 59 PHA bins.
# Reduced chi-squared = 1.287 for 55 degrees of freedom
# Null hypothesis probability = 7.463806e-02
Photon flux (15-150 keV) in 0.104 sec: 10.2505 ( -3.2505 -1.13968 ) 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) = 2.02e-08
S(50-100 keV) = 2.49e-08
T90 vs. Hardness ratio plot
T90 = 0.0920000076293945 sec.
Hardness ratio (energy fluence ratio) = 1.23267
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 1.67379
Count Ratio (50-100 keV) / (15-25 keV) = 1.52053
Mask shadow pattern
IMX = 9.625137830726542E-01, IMY = 2.706669988381329E-01
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:
-299.376000 -0.036000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
275.7787 -30.4459 9.9 44.4 -124.6 -0.8136 -1.2 8.9 H1820-303
285.0650 -24.9642 7.1 34.8 -121.3 0.5215 1.6 3.1 HT1900.1-2455
288.9102 11.0917 3.7 34.5 -55.0 0.9664 3.2 11.0 GRS 1915+105
299.5878 35.2084 0.4 47.0 -19.4 10.9058 29.2 0.4 Cyg X-1
308.2357 40.8451 57.1 50.3 -8.4 0.0925 0.2 8.6 Cyg X-3
326.1686 38.3077 3.8 47.7 9.9 1.3954 3.1 0.8 Cyg X-2
327.4683 40.5951 2.5 50.2 10.5 2.6116 4.6 ------ UNKNOWN
319.6869 48.3236 2.9 57.1 2.4 4.4707 3.9 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-0.036000 0.068000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
276.0435 -30.3004 4.5 44.2 -124.5 0.0347 2.6 7.3 H1820-303
285.0385 -25.0143 9.3 34.8 -121.4 0.0092 1.2 5.6 HT1900.1-2455
288.9379 10.8669 12.2 34.4 -55.3 0.0061 0.9 9.5 GRS 1915+105
299.7223 35.1844 12.8 46.9 -19.3 0.0084 0.9 6.6 Cyg X-1
307.9814 40.9475 4.2 50.4 -8.6 0.0304 2.7 5.8 Cyg X-3
326.0377 38.3722 6.8 47.8 9.7 -0.0202 -1.7 7.0 Cyg X-2
354.4076 -10.4088 2.2 36.6 96.3 0.0531 5.2 ------ UNKNOWN
303.4871 34.3295 0.7 45.0 -15.7 0.1468 16.8 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
75.124600 176.724600
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.3055 35.2023 0.0 40.0 -92.3 0.1390 0.3 11.2 Her X-1
268.2516 -1.3613 31.1 48.6 -147.8 -0.0995 -0.4 8.9 SW J1753.5-0127
274.0226 -14.0449 9.5 55.9 -162.9 0.4417 1.2 1.1 GX 17+2
288.7702 11.1049 367.0 26.8 -164.5 0.0036 0.0 9.7 GRS 1915+105
299.5831 35.2012 0.3 3.3 -92.1 3.9193 40.5 0.4 Cyg X-1
308.1393 40.9623 2.2 7.6 9.6 0.5074 5.2 1.4 Cyg X-3
326.0795 38.3577 4.8 18.6 52.9 0.2752 2.4 4.8 Cyg X-2
241.7101 61.4995 2.3 47.0 -53.2 2.5103 5.0 ------ UNKNOWN
Plot creation:
Sun May 31 15:30:55 EDT 2015