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
263.9289 13.0423 0.0105 9.0780 98.0474 0.5755504 18.303 TRIG_00231231
Foreground time interval of the image:
-0.092 10.140 (delta_t = 10.232 [sec])
Background time interval of the image:
-239.328 -0.092 (delta_t = 239.236 [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
8 ms binning
From T100_start-3 s to T100_start+3 s
2 ms binning
From T100_start-1 s to T100_start+1 s
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 -0.092 sec. to 10.140 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.49681 ( -0.213116 0.229232 )
Norm@50keV : 2.27213E-03 ( -0.000362901 0.000359504 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 38.41 using 59 PHA bins.
# Reduced chi-squared = 0.6738 for 57 degrees of freedom
# Null hypothesis probability = 9.721502e-01
Photon flux (15-150 keV) in 10.23 sec: 0.445480 ( -0.0426737 0.0426837 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.32231e-07 ( -2.68691e-08 2.76872e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.092 sec. to 10.140 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.95843 ( )
Epeak [keV] : 2.76236 ( )
Norm@50keV : 4.95270E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 38.59 using 59 PHA bins.
# Reduced chi-squared = 0.6891 for 56 degrees of freedom
# Null hypothesis probability = 9.633137e-01
Photon flux (15-150 keV) in 10.23 sec: 0.441691 ( -0.045626 0.045201 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.2631e-07 ( -3.51431e-08 3.24741e-08 ) ergs/cm2
Band function
Time interval is from -0.092 sec. to 10.140 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.208656 ( 1.46962 1.46962 )
beta : -2.69661 ( 2.61517 0.284667 )
Epeak [keV] : 20.2011 ( -14.937 32.617 )
Norm@50keV : 0.111039 ( -0.108895 1082.04 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 37.13 using 59 PHA bins.
# Reduced chi-squared = 0.6751 for 55 degrees of freedom
# Null hypothesis probability = 9.691612e-01
Photon flux (15-150 keV) in 10.23 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] : 6.90685 (-0.744188 0.841613)
R^2/D10^2 : 0.854173 (-0.331267 0.54552)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.20 using 59 PHA bins.
# Reduced chi-squared = 0.9859 for 57 degrees of freedom
# Null hypothesis probability = 5.051462e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 6.603e-08 1.092e-08
25- 50 8.809e-08 1.266e-08
50-150 1.390e-08 5.038e-09
15-150 1.680e-07 2.378e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 31.2175 (-6.869 9.695)
Norm : 3.39904 (-0.707751 0.947772)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 40.31 using 59 PHA bins.
# Reduced chi-squared = 0.7073 for 57 degrees of freedom
# Null hypothesis probability = 9.539002e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 7.218e-08 8.931e-09
25- 50 8.428e-08 1.074e-08
50-150 4.860e-08 1.673e-08
15-150 2.051e-07 2.593e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 5.09896 (-1.13426 1.09971)
R1^2/D10^2 : 2.57983 (-1.37761 4.47281)
kT2 [keV] : 18.2254 (-6.64024 18.3151)
R2^2/D10^2 : 9.21019E-03 (-0.00835721 0.054951)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 37.48 using 59 PHA bins.
# Reduced chi-squared = 0.6815 for 55 degrees of freedom
# Null hypothesis probability = 9.660002e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 7.562e-08 3.159e-08
25- 50 7.667e-08 2.943e-08
50-150 7.258e-08 4.170e-08
15-150 2.249e-07 8.835e-08
Peak spectrum fit
Power-law model
Time interval is from 0.368 sec. to 1.368 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.37986 ( -0.246672 0.26804 )
Norm@50keV : 6.02994E-03 ( -0.00115824 0.00114505 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.51 using 59 PHA bins.
# Reduced chi-squared = 0.9037 for 57 degrees of freedom
# Null hypothesis probability = 6.803699e-01
Photon flux (15-150 keV) in 1 sec: 1.10268 ( -0.136006 0.136007 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.85568e-08 ( -8.78927e-09 9.10985e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.368 sec. to 1.368 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.27241 ( -1.81675 0.725933 )
Epeak [keV] : 22.5822 ( )
Norm@50keV : 3.14269E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.33 using 59 PHA bins.
# Reduced chi-squared = 0.8809 for 56 degrees of freedom
# Null hypothesis probability = 7.235977e-01
Photon flux (15-150 keV) in 1 sec: 1.06785 ( -0.13916 0.14054 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.19541e-08 ( -9.1589e-09 1.14539e-08 ) ergs/cm2
Band function
Time interval is from 0.368 sec. to 1.368 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 4.57886 ( -12.1322 -4.57886 )
beta : -2.79910 ( -0.546178 0.397853 )
Epeak [keV] : 23.2635 ( -3.48573 3.18374 )
Norm@50keV : 1093.62 ( -133.399 11863.5 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.54 using 59 PHA bins.
# Reduced chi-squared = 0.8644 for 55 degrees of freedom
# Null hypothesis probability = 7.522598e-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] : 7.30970 (-0.928795 1.07619)
R^2/D10^2 : 1.74830 (-0.763554 1.34432)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.37 using 59 PHA bins.
# Reduced chi-squared = 0.9714 for 57 degrees of freedom
# Null hypothesis probability = 5.365344e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.566e-08 3.560e-09
25- 50 2.329e-08 4.205e-09
50-150 4.503e-09 1.744e-09
15-150 4.346e-08 8.125e-09
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 34.6146 (-9.00971 13.8831)
Norm : 7.91549 (-1.84035 2.51308)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.30 using 59 PHA bins.
# Reduced chi-squared = 0.8649 for 57 degrees of freedom
# Null hypothesis probability = 7.558790e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.721e-08 2.815e-09
25- 50 2.119e-08 3.695e-09
50-150 1.389e-08 5.733e-09
15-150 5.229e-08 9.920e-09
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 5.55543 (-2.06782 1.75198)
R1^2/D10^2 : 4.31751 (-2.65508 16.8569)
kT2 [keV] : 16.6064 (-6.90561 -16.6875)
R2^2/D10^2 : 3.07422E-02 (-0.0299897 0.544376)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 48.28 using 59 PHA bins.
# Reduced chi-squared = 0.8778 for 55 degrees of freedom
# Null hypothesis probability = 7.272691e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.745e-08 9.585e-09
25- 50 2.074e-08 1.074e-08
50-150 1.561e-08 9.989e-09
15-150 5.380e-08 2.727e-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: 2.49681 ( -0.213116 0.229232 )
Norm@50keV : 2.27213E-03 ( -0.000362901 0.000359504 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 38.41 using 59 PHA bins.
# Reduced chi-squared = 0.6738 for 57 degrees of freedom
# Null hypothesis probability = 9.721502e-01
Photon flux (15-150 keV) in 10.23 sec: 0.445480 ( -0.0426737 0.0426837 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.32231e-07 ( -2.68691e-08 2.76872e-08 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.95843 ( )
Epeak [keV] : 2.76236 ( )
Norm@50keV : 4.95270E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 38.59 using 59 PHA bins.
# Reduced chi-squared = 0.6891 for 56 degrees of freedom
# Null hypothesis probability = 9.633137e-01
Photon flux (15-150 keV) in 10.23 sec: 0.441691 ( -0.045626 0.045201 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.2631e-07 ( -3.51431e-08 3.24741e-08 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.208656 ( 1.46962 1.46962 )
beta : -2.69661 ( 2.61517 0.284666 )
Epeak [keV] : 20.2011 ( -14.937 32.617 )
Norm@50keV : 0.111039 ( -0.108895 1081.99 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 37.13 using 59 PHA bins.
# Reduced chi-squared = 0.6751 for 55 degrees of freedom
# Null hypothesis probability = 9.691612e-01
Photon flux (15-150 keV) in 10.23 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) = 7.70e-08
S(50-100 keV) = 5.46e-08
T90 vs. Hardness ratio plot
T90 = 8.824000030756 sec.
Hardness ratio (energy fluence ratio) = 0.709091
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 0.775258
Count Ratio (50-100 keV) / (15-25 keV) = 0.251842
Mask shadow pattern
IMX = -2.236794455097446E-02, IMY = -1.582073322667724E-01
TIME vs. PHA plot around the trigger time
TIME vs. DetID plot around the trigger time
100 us light curve (15-350 keV)
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:
-239.328000 -0.092000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
244.9743 -15.6390 0.2 29.6 -147.5 10.9997 49.6 0.3 Sco X-1
254.2773 35.3571 4.1 23.0 12.6 0.5384 2.8 8.9 Her X-1
255.9812 -37.8368 3.4 50.2 -168.0 1.6443 3.3 0.5 4U 1700-377
256.5301 -36.4529 5.0 48.8 -168.6 1.0097 2.3 4.9 GX 349+2
263.0999 -24.7496 2.2 38.0 -179.1 1.4811 5.4 5.0 GX 1+4
264.8316 -44.3870 9.6 57.5 -175.2 1.2592 1.2 5.4 4U 1735-44
268.3911 -1.3899 3.4 19.4 147.6 0.6455 3.4 4.0 SW J1753.5-0127
270.2642 -25.1202 3.2 40.5 171.3 1.0815 3.6 2.7 GX 5-1
270.3100 -25.8667 8.4 41.2 171.7 0.4325 1.4 7.4 GRS 1758-258
273.9546 -14.0514 10.1 32.6 156.9 0.3255 1.1 3.1 GX 17+2
276.0162 -30.2328 6.4 47.3 168.0 0.9194 1.8 9.3 H1820-303
284.9648 -25.1067 16.2 47.7 155.2 0.4484 0.7 11.8 HT1900.1-2455
288.8074 10.9169 1.1 33.5 102.2 4.4665 10.4 1.8 GRS 1915+105
262.9786 -33.8603 6.6 46.9 -176.1 0.6626 1.8 1.6 GX 354-0
274.6850 49.8332 2.4 40.9 33.1 2.0550 4.9 ------ UNKNOWN
242.3214 7.1518 3.0 13.2 -98.7 0.7833 3.8 ------ UNKNOWN
201.0634 46.4350 5.2 56.3 -28.4 2.7586 2.2 ------ UNKNOWN
216.8093 -4.1364 5.6 41.1 -98.0 2.4431 2.1 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-0.092000 10.140000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
245.1116 -15.7655 4.9 29.7 -147.8 -0.0860 -2.4 10.7 Sco X-1
254.5779 35.5170 0.0 23.2 13.2 0.0452 1.3 12.0 Her X-1
255.9703 -37.8212 695.0 50.2 -168.0 -0.0012 -0.0 1.6 4U 1700-377
256.6233 -36.5472 0.0 48.9 -168.7 0.1235 1.7 11.7 GX 349+2
262.9664 -24.8190 107.5 38.1 -178.9 -0.0049 -0.1 5.0 GX 1+4
264.7632 -44.4635 5.7 57.6 -175.2 -0.3597 -2.0 1.2 4U 1735-44
268.3577 -1.4905 6.4 19.4 147.9 -0.0599 -1.8 2.4 SW J1753.5-0127
270.3991 -25.0165 10.9 40.4 171.1 0.0517 1.1 7.3 GX 5-1
270.3964 -25.5988 3.2 40.9 171.4 0.1828 3.6 10.0 GRS 1758-258
274.1452 -14.0534 10.7 32.7 156.6 0.0470 1.1 8.2 GX 17+2
276.0038 -30.4998 3.0 47.5 168.2 -0.2924 -3.9 9.0 H1820-303
285.0721 -24.8114 4.1 47.6 154.9 -0.2929 -2.8 6.8 HT1900.1-2455
288.7125 10.8617 5.1 33.4 102.3 -0.1572 -2.3 7.1 GRS 1915+105
262.8403 -33.7815 16.9 46.8 -176.0 -0.0402 -0.7 8.1 GX 354-0
291.8355 -2.3888 2.2 39.8 122.6 0.5122 5.3 ------ UNKNOWN
263.9289 13.0423 0.6 9.1 98.0 0.5756 18.3 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
43.772620 875.972600
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
244.9831 -15.6442 0.2 34.3 -142.8 37.0285 47.7 0.3 Sco X-1
254.3161 35.3208 3.0 23.9 -16.2 2.0921 3.8 7.0 Her X-1
256.0052 -37.8557 4.5 51.5 -168.5 4.3000 2.6 1.1 4U 1700-377
256.4614 -36.5106 23.0 50.1 -168.7 0.6865 0.5 5.4 GX 349+2
263.0485 -24.7169 2.5 37.8 -175.2 3.7677 4.6 2.8 GX 1+4
264.8570 -44.4511 8.6 57.5 -177.3 -4.1665 -1.3 4.9 4U 1735-44
268.3236 -1.3586 2.6 15.1 166.4 2.3727 4.4 6.2 SW J1753.5-0127
270.2837 -25.0814 2.3 38.6 174.3 3.8547 5.0 0.1 GX 5-1
270.2966 -25.7398 6.0 39.3 174.4 1.4372 1.9 0.4 GRS 1758-258
273.9286 -14.0279 3.9 28.8 163.1 1.9651 3.0 4.5 GX 17+2
275.7966 -30.2335 0.0 44.8 168.9 -1.3544 -1.2 10.4 H1820-303
285.0102 -25.0211 4.9 43.3 155.1 3.2143 2.4 6.2 HT1900.1-2455
288.7877 10.9525 0.6 24.4 95.8 14.6205 18.1 0.8 GRS 1915+105
299.5832 35.2066 0.4 39.0 52.7 44.1743 32.2 0.5 Cyg X-1
262.9594 -33.8718 4.8 46.9 -175.4 2.3610 2.4 2.7 GX 354-0
277.3766 -23.7918 2.9 39.1 163.8 3.8169 4.0 ------ UNKNOWN
242.8039 53.9567 2.7 44.2 -14.2 4.2861 4.2 ------ UNKNOWN
243.2989 52.1869 3.3 42.5 -15.2 3.3788 3.5 ------ UNKNOWN
226.8433 -12.5235 3.1 44.8 -119.8 12.2431 3.8 ------ UNKNOWN
223.8687 2.3733 5.1 41.1 -98.1 8.9051 2.3 ------ UNKNOWN
Plot creation:
Sun May 31 11:55:39 EDT 2015