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
177.7695 57.1650 0.0130 22.0875 -178.3213 0.4939436 14.797 TRIG_00306858
Foreground time interval of the image:
-1.672 13.848 (delta_t = 15.520 [sec])
Background time interval of the image:
-239.120 -1.672 (delta_t = 237.448 [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 1.408000
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 1.408000
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 1.408000
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 -1.672 sec. to 13.848 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.62256 ( -0.208911 0.214044 )
Norm@50keV : 1.95787E-03 ( -0.000257725 0.000252945 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 43.19 using 59 PHA bins.
# Reduced chi-squared = 0.7577 for 57 degrees of freedom
# Null hypothesis probability = 9.117879e-01
Photon flux (15-150 keV) in 15.52 sec: 0.253385 ( -0.0296646 0.0296705 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.83426e-07 ( -3.98578e-08 4.07133e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.672 sec. to 13.848 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.50731 ( -0.907562 0.324837 )
Epeak [keV] : 189.118 ( -192.539 -192.539 )
Norm@50keV : 2.27154E-03 ( -0.000559044 0.00498656 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 43.13 using 59 PHA bins.
# Reduced chi-squared = 0.7702 for 56 degrees of freedom
# Null hypothesis probability = 8.961425e-01
Photon flux (15-150 keV) in 15.52 sec: 0.252171 ( -0.01543 0.030466 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.79674e-07 ( -4.81958e-08 4.36748e-08 ) ergs/cm2
Band function
Time interval is from -1.672 sec. to 13.848 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 4.48925 ( -4.48925 -4.48925 )
beta : -1.77526 ( -0.290876 0.258577 )
Epeak [keV] : 25.3753 ( -8.53129 5.1685 )
Norm@50keV : 91.2441 ( -10.6083 1.22234e+06 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 41.61 using 59 PHA bins.
# Reduced chi-squared = 0.7565 for 55 degrees of freedom
# Null hypothesis probability = 9.087634e-01
Photon flux (15-150 keV) in 15.52 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] : 11.6039 (-1.67596 2.06125)
R^2/D10^2 : 6.91010E-02 (-0.0308418 0.0530102)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.50 using 59 PHA bins.
# Reduced chi-squared = 1.061 for 57 degrees of freedom
# Null hypothesis probability = 3.506809e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.043e-08 7.155e-09
25- 50 9.201e-08 1.554e-08
50-150 7.280e-08 1.953e-08
15-150 1.952e-07 3.128e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 162.129 (-73.737 -160.553)
Norm : 1.03881 (-0.127699 0.171053)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 43.32 using 59 PHA bins.
# Reduced chi-squared = 0.7601 for 57 degrees of freedom
# Null hypothesis probability = 9.093466e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.111e-08 2.262e-08
25- 50 7.705e-08 4.130e-08
50-150 1.569e-07 8.908e-08
15-150 2.751e-07 1.526e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 7.68076 (-2.02056 2.16807)
R1^2/D10^2 : 0.242328 (-0.134875 0.490085)
kT2 [keV] : 36.8812 (-16.5005 -36.9392)
R2^2/D10^2 : 9.26036E-04 (-0.000894851 0.00584452)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 41.28 using 59 PHA bins.
# Reduced chi-squared = 0.7506 for 55 degrees of freedom
# Null hypothesis probability = 9.147771e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.153e-08 1.777e-08
25- 50 8.106e-08 3.017e-08
50-150 1.676e-07 8.993e-08
15-150 2.902e-07 1.228e-07
Peak spectrum fit
Power-law model
Time interval is from 0.052 sec. to 1.052 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.32727 ( -0.35733 0.353286 )
Norm@50keV : 4.65631E-03 ( -0.000988862 0.000984201 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.08 using 59 PHA bins.
# Reduced chi-squared = 0.9838 for 57 degrees of freedom
# Null hypothesis probability = 5.097363e-01
Photon flux (15-150 keV) in 1 sec: 0.558397 ( -0.118434 0.118644 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.57143e-08 ( -1.07416e-08 1.09719e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.052 sec. to 1.052 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.733487 ( -1.87773 1.64588 )
Epeak [keV] : 104.772 ( -104.773 -104.773 )
Norm@50keV : 9.43449E-03 ( -0.00564473 0.0773186 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.54 using 59 PHA bins.
# Reduced chi-squared = 0.9917 for 56 degrees of freedom
# Null hypothesis probability = 4.923194e-01
Photon flux (15-150 keV) in 1 sec: 0.546799 ( -0.122151 0.121698 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.35023e-08 ( -1.2065e-08 1.20971e-08 ) ergs/cm2
Band function
Time interval is from 0.052 sec. to 1.052 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 3.02292 ( -0.686297 -0.686297 )
beta : -1.63478 ( 1.58302 0.526079 )
Epeak [keV] : 36.3205 ( -42.4575 128.674 )
Norm@50keV : 3.37482 ( -3.36012 37.1934 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.83 using 59 PHA bins.
# Reduced chi-squared = 0.9970 for 55 degrees of freedom
# Null hypothesis probability = 4.809536e-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] : 15.4626 (-3.67617 5.30479)
R^2/D10^2 : 5.96107E-02 (-0.0379023 0.0926962)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.11 using 59 PHA bins.
# Reduced chi-squared = 1.037 for 57 degrees of freedom
# Null hypothesis probability = 3.985251e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.968e-09 1.416e-09
25- 50 1.212e-08 4.869e-09
50-150 1.998e-08 9.046e-09
15-150 3.507e-08 1.386e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 199.360 (-92.9972 -199.362)
Norm : 2.30406 (-0.484169 0.485203)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.69 using 59 PHA bins.
# Reduced chi-squared = 0.9946 for 57 degrees of freedom
# Null hypothesis probability = 4.864804e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 5.737e-09 3.444e-09
25- 50 1.104e-08 6.540e-09
50-150 2.421e-08 1.411e-08
15-150 4.098e-08 2.402e-08
Double BB
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 35.0837 ( )
R1^2/D10^2 : 2.70045E-03 (-0.00259619 0.0452448)
kT2 [keV] : 9.24117 (-5.42999 -9.24994)
R2^2/D10^2 : 0.236063 (-0.181429 3.15043)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.14 using 59 PHA bins.
#Fit statistic : Chi-Squared = 54.92 using 59 PHA bins.
# Reduced chi-squared = 1.002 for 55 degrees of freedom
# Reduced chi-squared = 0.9986 for 55 degrees of freedom
# Null hypothesis probability = 4.694745e-01
# Null hypothesis probability = 4.776409e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.459e-09 2.937e-09
25- 50 1.134e-08 6.280e-09
50-150 2.588e-08 1.571e-08
15-150 4.168e-08 2.264e-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: 1.62256 ( -0.208911 0.214044 )
Norm@50keV : 1.95787E-03 ( -0.000257725 0.000252945 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 43.19 using 59 PHA bins.
# Reduced chi-squared = 0.7577 for 57 degrees of freedom
# Null hypothesis probability = 9.117879e-01
Photon flux (15-150 keV) in 15.52 sec: 0.253385 ( -0.0296646 0.0296705 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.83426e-07 ( -3.98578e-08 4.07133e-08 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.50731 ( -0.907562 0.324837 )
Epeak [keV] : 189.118 ( -192.539 -192.539 )
Norm@50keV : 2.27154E-03 ( -0.000559044 0.00498656 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 43.13 using 59 PHA bins.
# Reduced chi-squared = 0.7702 for 56 degrees of freedom
# Null hypothesis probability = 8.961425e-01
Photon flux (15-150 keV) in 15.52 sec: 0.252171 ( -0.01543 0.030466 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.79674e-07 ( -4.81958e-08 4.38176e-08 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 4.48925 ( -4.48925 -4.48925 )
beta : -1.77526 ( -0.290876 0.258577 )
Epeak [keV] : 25.3753 ( -8.50592 5.16897 )
Norm@50keV : 91.2441 ( -10.6083 1.22234e+06 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 41.61 using 59 PHA bins.
# Reduced chi-squared = 0.7565 for 55 degrees of freedom
# Null hypothesis probability = 9.087634e-01
Photon flux (15-150 keV) in 15.52 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) = 7.42e-08
S(50-100 keV) = 9.64e-08
T90 vs. Hardness ratio plot
T90 = 13.8160000145435 sec.
Hardness ratio (energy fluence ratio) = 1.29919
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 1.29366
Count Ratio (50-100 keV) / (15-25 keV) = 0.854068
Mask shadow pattern
IMX = -4.056294241503268E-01, IMY = 1.188761161799625E-02
TIME vs. PHA plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 1.408000
TIME vs. DetID plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 1.408000
100 us light curve (15-350 keV)
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 1.408000
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:
-239.120000 -1.672000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.3504 35.4530 9.0 37.3 -48.2 0.3554 1.3 8.5 Her X-1
204.9581 -2.2351 2.6 46.3 47.2 3.3904 4.4 ------ UNKNOWN
220.0524 24.3710 2.4 22.7 11.3 0.8379 4.8 ------ UNKNOWN
223.8137 42.3050 2.1 12.8 -42.8 0.8491 5.4 ------ UNKNOWN
272.4188 64.6508 3.3 41.1 -98.2 3.3110 3.6 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-1.672000 13.848000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.3080 35.2121 12.6 37.4 -47.9 -0.0549 -0.9 10.7 Her X-1
191.1070 6.1474 2.6 40.2 69.2 0.6407 4.5 ------ UNKNOWN
177.7695 57.1650 0.8 22.1 -178.3 0.4939 14.8 ------ UNKNOWN
233.1466 20.3869 2.1 32.5 -6.6 0.2241 5.5 ------ UNKNOWN
207.8806 52.8815 2.0 8.9 -128.7 0.1889 5.7 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
81.980600 93.980590
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.3764 35.4802 6.0 20.2 21.4 -0.0599 -1.9 9.2 Her X-1
268.4484 -1.4423 2.6 57.4 -0.9 0.8041 4.4 4.9 SW J1753.5-0127
288.7043 10.8776 20.3 50.2 -28.9 -0.0460 -0.6 6.9 GRS 1915+105
299.5540 35.1577 2.7 34.2 -60.5 0.2263 4.2 3.2 Cyg X-1
308.1798 41.0285 5.8 34.9 -76.3 0.1265 2.0 5.5 Cyg X-3
256.8826 0.3139 2.4 55.1 13.0 0.8086 4.9 ------ UNKNOWN
234.9479 45.9162 1.9 17.8 78.3 0.2117 6.2 ------ UNKNOWN
265.0477 6.2056 2.2 49.4 2.5 0.3417 5.3 ------ UNKNOWN
89.7630 65.9263 2.0 58.4 -174.7 1.0499 5.6 ------ UNKNOWN
344.6890 56.7460 2.5 44.6 -118.5 0.5615 4.6 ------ UNKNOWN
Plot creation:
Sun May 31 08:00:11 EDT 2015