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
39.4759 30.8348 0.0208 25.9023 4.7075 0.1629767 9.243 TRIG_00338338
Foreground time interval of the image:
-0.128 2.872 (delta_t = 3.000 [sec])
Background time interval of the image:
-266.827 -0.128 (delta_t = 266.699 [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)
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 -0.128 sec. to 2.872 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.99891 ( -0.283642 0.309248 )
Norm@50keV : 3.35209E-03 ( -0.000709289 0.0006864 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.29 using 59 PHA bins.
# Reduced chi-squared = 0.9875 for 57 degrees of freedom
# Null hypothesis probability = 5.018691e-01
Photon flux (15-150 keV) in 3 sec: 0.502562 ( -0.0789864 0.078987 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.27354e-08 ( -1.80191e-08 1.87e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.128 sec. to 2.872 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.01158 ( -2.66291 1.12754 )
Epeak [keV] : 37.4211 ( )
Norm@50keV : 1.37421E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.42 using 59 PHA bins.
# Reduced chi-squared = 0.9897 for 56 degrees of freedom
# Null hypothesis probability = 4.966093e-01
Photon flux (15-150 keV) in 3 sec: 0.486694 ( -0.083213 0.042924 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.17965e-08 ( -2.02722e-08 1.31781e-08 ) ergs/cm2
Band function
Time interval is from -0.128 sec. to 2.872 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.375390 ( 0.346994 0.346994 )
beta : -2.55463 ( 2.55973 0.695919 )
Epeak [keV] : 34.1432 ( -33.995 19.5949 )
Norm@50keV : 3.74545E-02 ( -0.0438478 213.115 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.15 using 59 PHA bins.
# Reduced chi-squared = 0.9846 for 55 degrees of freedom
# Null hypothesis probability = 5.069449e-01
Photon flux (15-150 keV) in 3 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 8.55228e-08 ( 0 0 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 8.97943 (-1.35022 1.60935)
R^2/D10^2 : 0.365430 (-0.173758 0.320899)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.07 using 59 PHA bins.
# Reduced chi-squared = 1.019 for 57 degrees of freedom
# Null hypothesis probability = 4.357442e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.719e-08 4.987e-09
25- 50 3.641e-08 8.476e-09
50-150 1.379e-08 6.002e-09
15-150 6.739e-08 1.718e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 59.3977 (-22.1435 47.8607)
Norm : 2.66447 (-0.631212 0.84043)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.46 using 59 PHA bins.
# Reduced chi-squared = 0.9729 for 57 degrees of freedom
# Null hypothesis probability = 5.331510e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.006e-08 3.972e-09
25- 50 3.043e-08 7.488e-09
50-150 3.433e-08 1.592e-08
15-150 8.482e-08 2.075e-08
Double BB
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 8.14364 (-1.67487 1.41497)
R1^2/D10^2 : 0.500791 (-0.181916 0.425995)
kT2 [keV] : 195.694 ( )
R2^2/D10^2 : 4.19599E-05 (-2.57968e-05 0.005289)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.04 using 59 PHA bins.
#Fit statistic : Chi-Squared = 51.80 using 59 PHA bins.
# Reduced chi-squared = 0.9462 for 55 degrees of freedom
# Reduced chi-squared = 0.9417 for 55 degrees of freedom
# Null hypothesis probability = 5.883758e-01
# Null hypothesis probability = 5.978450e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.846e-08 6.819e-09
25- 50 3.413e-08 1.231e-08
50-150 4.259e-08 2.652e-08
15-150 9.519e-08 3.661e-08
Peak spectrum fit
Power-law model
Time interval is from -0.128 sec. to 0.872 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.81610 ( -0.365052 0.399346 )
Norm@50keV : 4.49016E-03 ( -0.00119946 0.0011587 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.07 using 59 PHA bins.
# Reduced chi-squared = 0.9485 for 57 degrees of freedom
# Null hypothesis probability = 5.858775e-01
Photon flux (15-150 keV) in 1 sec: 0.622638 ( -0.136608 0.136611 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.13163e-08 ( -1.07912e-08 1.12659e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.128 sec. to 0.872 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.509188 ( -4.95001 2.45749 )
Epeak [keV] : 41.9020 ( -8.97183 203.879 )
Norm@50keV : 0.111464 ( -0.162209 137.373 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.25 using 59 PHA bins.
# Reduced chi-squared = 0.9151 for 56 degrees of freedom
# Null hypothesis probability = 6.550533e-01
Photon flux (15-150 keV) in 1 sec: 0.578758 ( -0.138713 0.141933 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.26911e-08 ( -9.0363e-09 1.32821e-08 ) ergs/cm2
Band function
Time interval is from -0.128 sec. to 0.872 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 1.31931 ( -2.8913 -1.36121 )
beta : -2.83737 ( 2.84391 1.0275 )
Epeak [keV] : 38.3111 ( -12.065 13.5843 )
Norm@50keV : 0.393040 ( -0.491542 53.1021 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.55 using 59 PHA bins.
# Reduced chi-squared = 0.9192 for 55 degrees of freedom
# Null hypothesis probability = 6.450178e-01
Photon flux (15-150 keV) in 1 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 3.62836e-08 ( 0 0 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 10.3117 (-1.92198 2.47271)
R^2/D10^2 : 0.281468 (-0.158019 0.328165)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.34 using 59 PHA bins.
# Reduced chi-squared = 0.9007 for 57 degrees of freedom
# Null hypothesis probability = 6.864017e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 6.155e-09 2.535e-09
25- 50 1.597e-08 6.027e-09
50-150 9.104e-09 5.019e-09
15-150 3.123e-08 1.155e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 81.6754 (-39.5049 -81.6754)
Norm : 2.95327 (-0.750367 1.13135)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.80 using 59 PHA bins.
# Reduced chi-squared = 0.9264 for 57 degrees of freedom
# Null hypothesis probability = 6.331558e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 7.673e-09 2.766e-09
25- 50 1.269e-08 6.401e-09
50-150 1.817e-08 1.453e-08
15-150 3.854e-08 1.904e-08
Double BB
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 9.63122 ( )
R1^2/D10^2 : 0.343974 (-0.1901 4.04979)
kT2 [keV] : 199.363 (-199.363 -199.363)
R2^2/D10^2 : 2.98581E-05 (-3.7282e-05 0.453044)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.39 using 59 PHA bins.
#Fit statistic : Chi-Squared = 49.76 using 59 PHA bins.
# Reduced chi-squared = 0.9162 for 55 degrees of freedom
# Reduced chi-squared = 0.9047 for 55 degrees of freedom
# Null hypothesis probability = 6.510261e-01
# Null hypothesis probability = 6.744318e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 6.358e-09 2.905e-09
25- 50 1.545e-08 8.462e-09
50-150 9.769e-09 6.275e-09
15-150 3.158e-08 1.649e-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: 1.99891 ( -0.283642 0.309248 )
Norm@50keV : 3.35209E-03 ( -0.000709289 0.0006864 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.29 using 59 PHA bins.
# Reduced chi-squared = 0.9875 for 57 degrees of freedom
# Null hypothesis probability = 5.018691e-01
Photon flux (15-150 keV) in 3 sec: 0.502562 ( -0.0789864 0.078987 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.27354e-08 ( -1.80191e-08 1.87e-08 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.01158 ( -2.66291 1.11875 )
Epeak [keV] : 37.4211 ( )
Norm@50keV : 1.37421E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.42 using 59 PHA bins.
# Reduced chi-squared = 0.9897 for 56 degrees of freedom
# Null hypothesis probability = 4.966093e-01
Photon flux (15-150 keV) in 3 sec: 0.486694 ( -0.083213 0.042924 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.17965e-08 ( -2.02722e-08 1.31781e-08 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.375390 ( 0.346994 0.346994 )
beta : -2.55463 ( 2.55973 0.695919 )
Epeak [keV] : 34.1432 ( -33.995 19.5949 )
Norm@50keV : 3.74545E-02 ( -0.0438478 213.132 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.15 using 59 PHA bins.
# Reduced chi-squared = 0.9846 for 55 degrees of freedom
# Null hypothesis probability = 5.069449e-01
Photon flux (15-150 keV) in 3 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 8.55228e-08 ( 0 0 ) ergs/cm2
S(25-50 keV) vs. S(50-100 keV) plot
S(25-50 keV) = 2.79e-08
S(50-100 keV) = 2.79e-08
T90 vs. Hardness ratio plot
T90 = 3 sec.
Hardness ratio (energy fluence ratio) = 1
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 1.3343
Count Ratio (50-100 keV) / (15-25 keV) = 0.346791
Mask shadow pattern
IMX = 4.839855197255994E-01, IMY = -3.985472905366623E-02
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:
-266.827400 -0.128000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
83.6482 21.9887 0.8 39.4 80.5 10.6897 14.4 1.8 Crab
58.5796 -17.1100 2.2 25.8 171.1 1.0297 5.2 ------ UNKNOWN
23.5281 54.1909 2.1 51.8 1.7 2.9489 5.6 ------ UNKNOWN
16.5506 0.6626 2.8 30.3 -80.1 1.1146 4.0 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-0.128000 2.872000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
83.6424 22.0237 164.7 39.4 80.5 0.0049 0.1 0.8 Crab
76.8603 -1.7759 2.5 31.3 121.6 0.1338 4.6 ------ UNKNOWN
39.4759 30.8349 1.2 25.9 4.7 0.1630 9.2 ------ UNKNOWN
42.8218 -29.8312 2.4 35.8 -156.0 0.1007 4.9 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
61.972590 119.572590
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
53.5882 -19.3789 2.1 52.0 169.7 1.4407 5.5 ------ UNKNOWN
343.6584 63.4051 2.4 47.6 -23.4 0.6928 4.8 ------ UNKNOWN
10.8435 -7.4790 3.2 47.1 -132.9 0.9329 3.6 ------ UNKNOWN
Plot creation:
Sun May 31 05:12:13 EDT 2015