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
323.9115 6.8727 0.0128 15.3614 -25.2467 1.7814770 14.984 TRIG_00238174
Foreground time interval of the image:
-16.504 105.197 (delta_t = 121.701 [sec])
Background time interval of the image:
-239.104 -16.504 (delta_t = 222.600 [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 4.096000
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 4.096000
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 4.096000
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 -16.504 sec. to 132.676 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.01640 ( -0.154898 0.150811 )
Norm@50keV : 8.42845E-04 ( -7.16296e-05 7.13715e-05 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.60 using 59 PHA bins.
# Reduced chi-squared = 1.011 for 57 degrees of freedom
# Null hypothesis probability = 4.526863e-01
Photon flux (15-150 keV) in 149.2 sec: 9.71261E-02 ( -0.00843491 0.00847926 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.35198e-06 ( -1.22429e-07 1.23114e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -16.504 sec. to 132.676 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.839032 ( -0.624286 0.309426 )
Epeak [keV] : 378.048 ( -378.048 -378.048 )
Norm@50keV : 1.00959E-03 ( -0.000227436 0.0008399 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.31 using 59 PHA bins.
# Reduced chi-squared = 1.023 for 56 degrees of freedom
# Null hypothesis probability = 4.261556e-01
Photon flux (15-150 keV) in 149.2 sec: 9.63033E-02 ( -0.008835 0.0088037 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.34021e-06 ( -1.30183e-07 1.28997e-07 ) ergs/cm2
Band function
Time interval is from -16.504 sec. to 132.676 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.888223 ( 0.888223 0.888223 )
beta : -1.01640 ( -0.150715 0.155225 )
Epeak [keV] : 29.5428 ( )
Norm@50keV : 1.35194E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.60 using 59 PHA bins.
# Reduced chi-squared = 1.047 for 55 degrees of freedom
# Null hypothesis probability = 3.790752e-01
Photon flux (15-150 keV) in 149.2 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] : 22.6476 (-2.57905 3.07441)
R^2/D10^2 : 3.11566E-03 (-0.00101914 0.00145524)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 80.12 using 59 PHA bins.
# Reduced chi-squared = 1.406 for 57 degrees of freedom
# Null hypothesis probability = 2.341585e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.353e-08 7.833e-09
25- 50 2.341e-07 3.126e-08
50-150 8.973e-07 1.204e-07
15-150 1.175e-06 1.456e-07
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 ( )
Norm : 0.400974 (-0.0349225 0.0349182)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 91.83 using 59 PHA bins.
# Reduced chi-squared = 1.611 for 57 degrees of freedom
# Null hypothesis probability = 2.365067e-03
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.490e-07 2.532e-08
25- 50 2.866e-07 5.140e-08
50-150 6.287e-07 2.817e-07
15-150 1.064e-06 4.842e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 7.48263 (-2.45007 3.50636)
R1^2/D10^2 : 5.46826E-02 (-0.0373604 0.166095)
kT2 [keV] : 32.8716 (-6.82403 16.627)
R2^2/D10^2 : 8.70985E-04 (-0.000615056 0.000978843)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.79 using 59 PHA bins.
# Reduced chi-squared = 1.033 for 55 degrees of freedom
# Null hypothesis probability = 4.081977e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 9.897e-08 4.624e-08
25- 50 2.540e-07 9.903e-08
50-150 9.960e-07 3.610e-07
15-150 1.349e-06 5.267e-07
Peak spectrum fit
Power-law model
Time interval is from -7.856 sec. to -6.856 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.01741 ( -0.394405 0.372741 )
Norm@50keV : 4.01973E-03 ( -0.000906038 0.000903127 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.13 using 59 PHA bins.
# Reduced chi-squared = 0.8795 for 57 degrees of freedom
# Null hypothesis probability = 7.284068e-01
Photon flux (15-150 keV) in 1 sec: 0.463186 ( -0.105778 0.106084 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.32036e-08 ( -1.05179e-08 1.07061e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -7.856 sec. to -6.856 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -7.03311E-02 ( -2.66645 1.25964 )
Epeak [keV] : 105.184 ( )
Norm@50keV : 1.26381E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 48.80 using 59 PHA bins.
# Reduced chi-squared = 0.8715 for 56 degrees of freedom
# Null hypothesis probability = 7.414508e-01
Photon flux (15-150 keV) in 1 sec: 0.442534 ( -0.111123 0.110895 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.04239e-08 ( -1.14053e-08 1.16329e-08 ) ergs/cm2
Band function
Time interval is from -7.856 sec. to -6.856 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 6.06260E-02 ( -8.87106 2.03396 )
beta : -9.30112 ( 8.41589 18.4159 )
Epeak [keV] : 106.071 ( -106.071 259.954 )
Norm@50keV : 1.24665E-02 ( -0.012453 0.0171001 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 48.80 using 59 PHA bins.
# Reduced chi-squared = 0.8873 for 55 degrees of freedom
# Null hypothesis probability = 7.089571e-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] : 20.5343 (-4.79099 7.21151)
R^2/D10^2 : 2.09502E-02 (-0.0128592 0.0283413)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.70 using 59 PHA bins.
# Reduced chi-squared = 0.8720 for 57 degrees of freedom
# Null hypothesis probability = 7.427421e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.685e-09 8.922e-10
25- 50 8.538e-09 3.347e-09
50-150 2.678e-08 1.471e-08
15-150 3.700e-08 1.613e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 ( )
Norm : 1.87449 (-0.438187 0.438169)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.85 using 59 PHA bins.
# Reduced chi-squared = 0.9623 for 57 degrees of freedom
# Null hypothesis probability = 5.562363e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.667e-09 2.755e-09
25- 50 8.978e-09 5.300e-09
50-150 1.969e-08 1.155e-08
15-150 3.334e-08 1.981e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 6.05596 (-5.89832 -5.89832)
R1^2/D10^2 : 0.336432 (-0.342783 -0.342783)
kT2 [keV] : 23.9464 (-7.07139 -23.9021)
R2^2/D10^2 : 1.18270E-02 (-0.0118496 0.0276298)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 48.46 using 59 PHA bins.
# Reduced chi-squared = 0.8812 for 55 degrees of freedom
# Null hypothesis probability = 7.208778e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.866e-09 1.688e-09
25- 50 8.373e-09 4.365e-09
50-150 2.872e-08 1.701e-08
15-150 3.996e-08 2.180e-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: 0.925844 ( -0.160291 0.154697 )
Norm@50keV : 9.09012E-04 ( -8.03102e-05 7.9689e-05 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 66.47 using 59 PHA bins.
# Reduced chi-squared = 1.166 for 57 degrees of freedom
# Null hypothesis probability = 1.829866e-01
Photon flux (15-150 keV) in 121.7 sec: 0.104373 ( -0.00926308 0.00930381 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.22927e-06 ( -1.11664e-07 1.12361e-07 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.818759 ( -0.615926 0.246792 )
Epeak [keV] : 651.214 ( -651.214 -651.214 )
Norm@50keV : 1.01131E-03 ( -0.000162324 0.000800253 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 66.37 using 59 PHA bins.
# Reduced chi-squared = 1.185 for 56 degrees of freedom
# Null hypothesis probability = 1.618284e-01
Photon flux (15-150 keV) in 121.7 sec: 0.103857 ( -0.0096296 0.009593 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.22369e-06 ( -1.16525e-07 1.15542e-07 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 5.00000 ( -4.99999 -4.99999 )
beta : -0.987433 ( -0.179779 0.177667 )
Epeak [keV] : 28.7281 ( -28.7281 7.90304 )
Norm@50keV : 26.1226 ( -2.19875 138917 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 65.46 using 59 PHA bins.
# Reduced chi-squared = 1.190 for 55 degrees of freedom
# Null hypothesis probability = 1.579933e-01
Photon flux (15-150 keV) in 121.7 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) = 2.53e-07
S(50-100 keV) = 5.00e-07
T90 vs. Hardness ratio plot
T90 = 135.247999995947 sec.
Hardness ratio (energy fluence ratio) = 1.97628
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 1.74173
Count Ratio (50-100 keV) / (15-25 keV) = 1.70026
Mask shadow pattern
IMX = 2.484801929546569E-01, IMY = 1.171732314646718E-01
TIME vs. PHA plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 4.096000
TIME vs. DetID plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 4.096000
100 us light curve (15-350 keV)
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 4.096000
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:
-239.104000 -16.504000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
288.7255 10.7719 24.0 49.1 -45.5 0.3586 0.5 11.3 GRS 1915+105
299.5718 35.2126 0.5 50.8 -10.9 8.2379 22.6 1.1 Cyg X-1
308.2236 40.9992 21.7 50.2 0.7 0.2015 0.5 5.8 Cyg X-3
326.0558 38.2722 2.9 41.6 16.1 1.0354 3.9 6.2 Cyg X-2
342.4915 13.8394 2.9 17.2 48.9 0.6007 4.0 ------ UNKNOWN
357.7319 -57.2298 3.5 57.5 -165.4 2.6515 3.3 ------ UNKNOWN
296.5605 -4.4317 4.7 39.7 -66.0 1.1499 2.5 ------ UNKNOWN
300.6208 -24.7240 4.3 41.1 -98.1 2.2764 2.7 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-16.504000 105.196600
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
288.7232 10.7781 5.4 49.1 -45.5 1.0855 2.2 11.0 GRS 1915+105
299.5666 35.2261 1.2 50.8 -10.9 -2.7248 -9.7 1.9 Cyg X-1
308.1556 41.0238 3.9 50.3 0.6 0.8435 3.0 4.7 Cyg X-3
326.0372 38.2702 6.0 41.6 16.0 -0.3863 -1.9 7.0 Cyg X-2
3.5978 29.4250 2.2 41.1 65.6 2.5420 5.3 ------ UNKNOWN
0.9952 0.0213 2.0 24.8 113.2 0.9188 5.8 59.7 UNKNOWN
323.9115 6.8727 0.8 15.4 -25.2 1.7817 15.0 ------ UNKNOWN
290.3735 14.8060 2.3 48.5 -39.7 1.7162 4.9 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
250.396600 963.006000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
135.4706 -40.5681 4.9 32.3 -161.9 0.9062 2.4 2.8 Vela X-1
170.2856 -60.7002 2.7 33.7 -106.7 2.5454 4.3 4.7 Cen X-3
186.6906 -62.7661 3.0 38.5 -95.7 5.3173 3.9 1.0 GX 301-2
67.4579 -36.3564 3.0 31.2 85.0 2.3136 3.8 ------ UNKNOWN
5.9248 -73.6540 3.1 31.6 -15.9 1.3724 3.7 ------ UNKNOWN
174.2359 -47.0567 3.0 44.8 -119.9 6.1673 3.9 ------ UNKNOWN
Plot creation:
Sun May 31 11:29:51 EDT 2015