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
121.2450 -45.5633 0.0060 48.2831 146.8139 17.2951050 31.925 TRIG_00276321
Foreground time interval of the image:
-29.136 23.677 (delta_t = 52.813 [sec])
Background time interval of the image:
-239.424 -29.136 (delta_t = 210.288 [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 2.048000
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 2.048000
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 2.048000
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 -29.136 sec. to 100.276 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.50698 ( -0.0509565 0.0509578 )
Norm@50keV : 1.17873E-02 ( -0.000332415 0.000332411 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.74 using 59 PHA bins.
# Reduced chi-squared = 0.9428 for 57 degrees of freedom
# Null hypothesis probability = 5.981293e-01
Photon flux (15-150 keV) in 129.4 sec: 1.47429 ( -0.0465685 0.0467129 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.44531e-05 ( -4.22171e-07 4.22503e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -29.136 sec. to 100.276 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.13231 ( -0.216844 0.207276 )
Epeak [keV] : 130.335 ( -28.0953 87.4448 )
Norm@50keV : 1.73864E-02 ( -0.0032848 0.00424934 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 43.91 using 59 PHA bins.
# Reduced chi-squared = 0.7841 for 56 degrees of freedom
# Null hypothesis probability = 8.795263e-01
Photon flux (15-150 keV) in 129.4 sec: 1.43690 ( -0.05025 0.05046 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.41892e-05 ( -4.51347e-07 4.49924e-07 ) ergs/cm2
Band function
Time interval is from -29.136 sec. to 100.276 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.13631 ( -0.1914 0.203697 )
beta : -9.37124 ( 9.37166 19.3717 )
Epeak [keV] : 131.554 ( -17.3824 37.3506 )
Norm@50keV : 1.73190E-02 ( -0.00240094 0.00267117 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 43.92 using 59 PHA bins.
# Reduced chi-squared = 0.7986 for 55 degrees of freedom
# Null hypothesis probability = 8.581924e-01
Photon flux (15-150 keV) in 129.4 sec: 1.43706 ( ) 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] : 17.3585 ( )
R^2/D10^2 : 9.85486E-02 ( )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 281.21 using 59 PHA bins.
# Reduced chi-squared = 4.9335 for 57 degrees of freedom
# Null hypothesis probability = 2.191422e-31
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 7.779e-07 4.458e-08
25- 50 3.499e-06 1.508e-07
50-150 7.577e-06 3.694e-07
15-150 1.185e-05 3.520e-07
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 ( )
Norm : 6.07601 (-0.171279 0.171276)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.86 using 59 PHA bins.
# Reduced chi-squared = 0.9098 for 57 degrees of freedom
# Null hypothesis probability = 6.679011e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.958e-06 5.758e-08
25- 50 3.767e-06 1.223e-07
50-150 8.261e-06 2.575e-07
15-150 1.399e-05 4.400e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 7.17431 (-0.757391 0.83274)
R1^2/D10^2 : 1.28303 (-0.401836 0.633817)
kT2 [keV] : 26.1791 (-2.0543 2.62133)
R2^2/D10^2 : 1.90682E-02 (-0.0057393 0.00695455)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 42.98 using 59 PHA bins.
# Reduced chi-squared = 0.7814 for 55 degrees of freedom
# Null hypothesis probability = 8.805393e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.694e-06 1.650e-07
25- 50 3.684e-06 2.873e-07
50-150 8.750e-06 5.590e-07
15-150 1.413e-05 7.887e-07
Peak spectrum fit
Power-law model
Time interval is from 1.404 sec. to 2.404 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.39511 ( -0.169085 0.169455 )
Norm@50keV : 5.80484E-02 ( -0.00587169 0.0058638 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.82 using 59 PHA bins.
# Reduced chi-squared = 0.8916 for 57 degrees of freedom
# Null hypothesis probability = 7.047841e-01
Photon flux (15-150 keV) in 1 sec: 7.06142 ( -0.740625 0.742201 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.61465e-07 ( -6.13163e-08 6.15742e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.404 sec. to 2.404 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.00930 ( -0.760931 0.47131 )
Epeak [keV] : 138.510 ( )
Norm@50keV : 8.88550E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.85 using 59 PHA bins.
# Reduced chi-squared = 0.8903 for 56 degrees of freedom
# Null hypothesis probability = 7.053055e-01
Photon flux (15-150 keV) in 1 sec: 6.96605 ( -0.75986 0.75996 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.52773e-07 ( -6.4482e-08 6.3946e-08 ) ergs/cm2
Band function
Time interval is from 1.404 sec. to 2.404 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.897191 ( 0.895729 0.895729 )
beta : -1.68478 ( 1.69202 0.429124 )
Epeak [keV] : 111.607 ( -112.631 546.619 )
Norm@50keV : 0.102857 ( -0.045456 0 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.79 using 59 PHA bins.
# Reduced chi-squared = 0.9052 for 55 degrees of freedom
# Null hypothesis probability = 6.734840e-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] : 17.0254 (-2.08181 2.42459)
R^2/D10^2 : 0.539184 (-0.199595 0.308409)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 69.34 using 59 PHA bins.
# Reduced chi-squared = 1.217 for 57 degrees of freedom
# Null hypothesis probability = 1.265140e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.182e-08 6.340e-09
25- 50 1.410e-07 2.150e-08
50-150 2.918e-07 5.685e-08
15-150 4.646e-07 6.135e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 ( )
Norm : 29.4350 (-2.97626 2.97607)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.82 using 59 PHA bins.
# Reduced chi-squared = 0.9267 for 57 degrees of freedom
# Null hypothesis probability = 6.323883e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 7.329e-08 2.085e-08
25- 50 1.410e-07 5.254e-08
50-150 3.092e-07 1.683e-07
15-150 5.235e-07 2.556e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 7.64847 (-3.36578 4.26216)
R1^2/D10^2 : 4.68604 (-3.29326 32.9402)
kT2 [keV] : 27.1423 (-7.19796 36.3708)
R2^2/D10^2 : 8.64481E-02 (-0.0802018 0.0943676)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.16 using 59 PHA bins.
# Reduced chi-squared = 0.9303 for 55 degrees of freedom
# Null hypothesis probability = 6.219505e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 5.842e-08 3.141e-08
25- 50 1.398e-07 6.897e-08
50-150 3.530e-07 1.781e-07
15-150 5.512e-07 2.790e-07
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: 1.44447 ( -0.0528142 0.0527539 )
Norm@50keV : 2.40068E-02 ( -0.00072047 0.00072038 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.92 using 59 PHA bins.
# Reduced chi-squared = 1.104 for 57 degrees of freedom
# Null hypothesis probability = 2.748061e-01
Photon flux (15-150 keV) in 52.81 sec: 2.95447 ( -0.0985245 0.0988125 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.21443e-05 ( -3.76469e-07 3.76745e-07 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.913792 ( -0.237266 0.225861 )
Epeak [keV] : 116.697 ( -19.4779 43.5408 )
Norm@50keV : 4.13827E-02 ( -0.00835931 0.0110368 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 45.87 using 59 PHA bins.
# Reduced chi-squared = 0.8191 for 56 degrees of freedom
# Null hypothesis probability = 8.308741e-01
Photon flux (15-150 keV) in 52.81 sec: 2.85767 ( -0.1051 0.10557 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.18706e-05 ( -3.9993e-07 3.98187e-07 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.913760 ( -0.198396 0.246313 )
beta : -10.0000 ( 10 1.06581e-14 )
Epeak [keV] : 116.677 ( -11.8001 43.543 )
Norm@50keV : 4.13811E-02 ( -0.00836608 0.011025 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 45.87 using 59 PHA bins.
# Reduced chi-squared = 0.8340 for 55 degrees of freedom
# Null hypothesis probability = 8.048850e-01
Photon flux (15-150 keV) in 52.81 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 1.18642e-05 ( 0 0 ) ergs/cm2
S(25-50 keV) vs. S(50-100 keV) plot
S(25-50 keV) = 3.59e-06
S(50-100 keV) = 5.05e-06
T90 vs. Hardness ratio plot
T90 = 77.0240000188351 sec.
Hardness ratio (energy fluence ratio) = 1.40669
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 1.64886
Count Ratio (50-100 keV) / (15-25 keV) = 1.4423
Mask shadow pattern
IMX = -9.387541668664886E-01, IMY = -6.139774823812880E-01
TIME vs. PHA plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 2.048000
TIME vs. DetID plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 2.048000
100 us light curve (15-350 keV)
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 2.048000
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:
-239.424000 -29.136000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
83.6244 22.0166 0.3 31.1 -66.2 8.3941 36.7 0.5 Crab
142.0229 30.1576 2.5 43.9 25.1 1.4176 4.7 ------ UNKNOWN
113.1446 -12.5408 2.3 14.8 137.1 0.7075 5.0 ------ UNKNOWN
85.5940 -49.7674 2.8 54.2 177.0 2.2606 4.1 ------ UNKNOWN
67.9574 -24.4639 2.4 45.9 -146.7 1.6338 4.8 ------ UNKNOWN
63.7116 -3.4825 3.3 43.8 -116.3 2.2696 3.5 ------ UNKNOWN
77.6108 41.4706 3.2 48.4 -49.9 2.5549 3.6 ------ UNKNOWN
69.0037 17.3697 2.9 41.0 -84.5 2.7205 3.9 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-29.136000 23.676600
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
83.6178 22.0160 7.6 31.1 -66.2 0.1715 1.5 0.9 Crab
121.2450 -45.5634 0.4 48.3 146.8 17.2891 31.9 ------ UNKNOWN
107.9475 -0.6480 2.4 1.9 139.9 0.4187 4.7 ------ UNKNOWN
66.9577 -42.2312 2.4 56.6 -165.1 1.8282 4.8 ------ UNKNOWN
60.6744 -15.1875 2.2 48.9 -131.5 1.8230 5.3 ------ UNKNOWN
61.9379 -10.0652 3.0 46.5 -125.2 1.3584 3.8 ------ UNKNOWN
62.5896 -7.2607 2.3 45.4 -121.5 1.7427 5.1 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
87.876580 962.606000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
135.5317 -40.5605 0.5 11.6 64.0 8.6361 22.3 0.4 Vela X-1
170.2031 -60.6321 4.1 32.1 130.3 1.6949 2.8 3.4 Cen X-3
186.6571 -62.8135 3.0 39.8 134.0 3.6663 3.8 2.6 GX 301-2
202.3188 -64.5201 2.9 46.3 138.5 6.1138 4.1 ------ UNKNOWN
204.7562 -70.7743 1.9 45.6 147.2 7.6893 6.2 ------ UNKNOWN
120.2109 -23.8568 4.4 21.7 -8.0 0.9473 2.6 ------ UNKNOWN
108.0531 -66.5327 2.4 22.1 -171.6 1.9276 4.8 ------ UNKNOWN
102.3352 -5.8633 3.8 42.9 -33.7 2.0915 3.0 ------ UNKNOWN
75.5074 -26.2478 3.2 41.0 -83.5 8.5032 3.6 ------ UNKNOWN
Plot creation:
Sun May 31 10:29:31 EDT 2015