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
282.3334 8.3285 0.0067 4.5154 89.9173 1.4445643 28.424 TRIG_00203755
Foreground time interval of the image:
-6.168 14.061 (delta_t = 20.229 [sec])
Background time interval of the image:
-239.240 -6.168 (delta_t = 233.072 [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 -6.168 sec. to 33.172 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.05151 ( -0.0916052 0.089951 )
Norm@50keV : 3.24730E-03 ( -0.000169014 0.000168649 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.34 using 59 PHA bins.
# Reduced chi-squared = 0.9357 for 57 degrees of freedom
# Null hypothesis probability = 6.132866e-01
Photon flux (15-150 keV) in 39.34 sec: 0.375097 ( -0.0201652 0.0201977 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.35705e-06 ( -7.40221e-08 7.42055e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -6.168 sec. to 33.172 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.693091 ( -0.378324 0.352124 )
Epeak [keV] : 205.878 ( -77.3009 2099.56 )
Norm@50keV : 4.71590E-03 ( -0.00134366 0.00217095 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.20 using 59 PHA bins.
# Reduced chi-squared = 0.8964 for 56 degrees of freedom
# Null hypothesis probability = 6.930908e-01
Photon flux (15-150 keV) in 39.34 sec: 0.369071 ( -0.020959 0.020981 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.33059e-06 ( -7.97776e-08 7.92465e-08 ) ergs/cm2
Band function
Time interval is from -6.168 sec. to 33.172 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 4.99998 ( -14.9998 -4.99998 )
beta : -1.19000 ( -0.113362 0.111565 )
Epeak [keV] : 32.7004 ( -4.68295 3.81118 )
Norm@50keV : 49.6164 ( -2.51364 71.4156 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.05 using 59 PHA bins.
# Reduced chi-squared = 0.8010 for 55 degrees of freedom
# Null hypothesis probability = 8.548508e-01
Photon flux (15-150 keV) in 39.34 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] : 21.2099 (-1.48664 1.65289)
R^2/D10^2 : 1.47085E-02 (-0.00315875 0.00392631)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 106.41 using 59 PHA bins.
# Reduced chi-squared = 1.8669 for 57 degrees of freedom
# Null hypothesis probability = 7.916751e-05
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.897e-08 5.331e-09
25- 50 2.533e-07 1.998e-08
50-150 8.498e-07 7.160e-08
15-150 1.152e-06 6.747e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 199.363 ( )
Norm : 1.57071 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 135.75 using 59 PHA bins.
# Reduced chi-squared = 2.3816 for 57 degrees of freedom
# Null hypothesis probability = 2.261238e-08
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.539e-07 8.970e-09
25- 50 2.960e-07 1.829e-08
50-150 6.491e-07 1.123e-07
15-150 1.099e-06 7.789e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 10.2455 (-1.7869 2.02816)
R1^2/D10^2 : 9.20500E-02 (-0.0354831 0.065165)
kT2 [keV] : 41.5935 (-9.31581 22.3596)
R2^2/D10^2 : 1.45888E-03 (-0.000996284 0.00110948)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.18 using 59 PHA bins.
# Reduced chi-squared = 0.8033 for 55 degrees of freedom
# Null hypothesis probability = 8.515833e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 9.048e-08 1.806e-08
25- 50 2.866e-07 5.319e-08
50-150 9.732e-07 4.033e-07
15-150 1.350e-06 4.382e-07
Peak spectrum fit
Power-law model
Time interval is from 1.808 sec. to 2.808 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.790429 ( -0.221996 0.209754 )
Norm@50keV : 8.27168E-03 ( -0.00113361 0.0011195 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 67.91 using 59 PHA bins.
# Reduced chi-squared = 1.191 for 57 degrees of freedom
# Null hypothesis probability = 1.528125e-01
Photon flux (15-150 keV) in 1 sec: 0.951018 ( -0.126357 0.126984 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.7053e-08 ( -1.29391e-08 1.30004e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.808 sec. to 2.808 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.541924 ( -1.27392 0.973108 )
Epeak [keV] : 115.558 ( -29.1659 135.975 )
Norm@50keV : 2.95683E-02 ( -0.0175646 0.0599892 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.96 using 59 PHA bins.
# Reduced chi-squared = 1.106 for 56 degrees of freedom
# Null hypothesis probability = 2.720980e-01
Photon flux (15-150 keV) in 1 sec: 0.907681 ( -0.129532 0.130529 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.24586e-08 ( -1.38681e-08 1.38054e-08 ) ergs/cm2
Band function
Time interval is from 1.808 sec. to 2.808 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.542385 ( -0.795076 1.40935 )
beta : -10.0000 ( 10 7.10543e-15 )
Epeak [keV] : 115.528 ( -21.3562 136.619 )
Norm@50keV : 2.95837E-02 ( -0.0175802 0.0600602 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.96 using 59 PHA bins.
# Reduced chi-squared = 1.126 for 55 degrees of freedom
# Null hypothesis probability = 2.419249e-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] : 24.7786 (-3.62629 4.69091)
R^2/D10^2 : 2.56287E-02 (-0.0104812 0.0162207)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 63.23 using 59 PHA bins.
# Reduced chi-squared = 1.109 for 57 degrees of freedom
# Null hypothesis probability = 2.658607e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.746e-09 7.840e-10
25- 50 1.551e-08 3.325e-09
50-150 7.070e-08 1.588e-08
15-150 8.896e-08 1.707e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 ( )
Norm : 3.76155 (-0.532057 0.53203)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 100.42 using 59 PHA bins.
# Reduced chi-squared = 1.7618 for 57 degrees of freedom
# Null hypothesis probability = 3.406452e-04
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 9.362e-09 5.345e-09
25- 50 1.801e-08 1.014e-08
50-150 3.950e-08 2.182e-08
15-150 6.687e-08 3.760e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 10.8412 (-10.9055 -10.9055)
R1^2/D10^2 : 8.78615E-02 (-0.0860201 -0.0860201)
kT2 [keV] : 30.3626 (-30.4636 -30.4636)
R2^2/D10^2 : 1.19767E-02 (-0.0118575 0.0229687)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.56 using 59 PHA bins.
# Reduced chi-squared = 1.119 for 55 degrees of freedom
# Null hypothesis probability = 2.530702e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.866e-09 2.328e-09
25- 50 1.660e-08 8.560e-09
50-150 7.280e-08 3.921e-08
15-150 9.327e-08 4.851e-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: 0.811398 ( -0.0908575 0.0885472 )
Norm@50keV : 4.65345E-03 ( -0.000250459 0.000248638 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.01 using 59 PHA bins.
# Reduced chi-squared = 1.123 for 57 degrees of freedom
# Null hypothesis probability = 2.441793e-01
Photon flux (15-150 keV) in 20.23 sec: 0.534632 ( -0.0280736 0.0281419 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.09487e-06 ( -5.64409e-08 5.65329e-08 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.194290 ( -0.416702 0.376645 )
Epeak [keV] : 180.383 ( -47.802 172.295 )
Norm@50keV : 8.31879E-03 ( -0.0024234 0.00373334 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.71 using 59 PHA bins.
# Reduced chi-squared = 0.9948 for 56 degrees of freedom
# Null hypothesis probability = 4.858398e-01
Photon flux (15-150 keV) in 20.23 sec: 0.520558 ( -0.029267 0.029325 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.07079e-06 ( -5.96927e-08 5.9371e-08 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.737328 ( 0.737328 0.737328 )
beta : -0.811401 ( -0.0884544 0.0908131 )
Epeak [keV] : 16.6065 ( )
Norm@50keV : 6.76047E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.01 using 59 PHA bins.
# Reduced chi-squared = 1.164 for 55 degrees of freedom
# Null hypothesis probability = 1.898040e-01
Photon flux (15-150 keV) in 20.23 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) = 2.60e-07
S(50-100 keV) = 5.02e-07
T90 vs. Hardness ratio plot
T90 = 30.5879999995232 sec.
Hardness ratio (energy fluence ratio) = 1.93077
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 2.09712
Count Ratio (50-100 keV) / (15-25 keV) = 1.99608
Mask shadow pattern
IMX = 1.140449292239489E-04, IMY = -7.897123620050106E-02
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:
-239.240000 -6.168000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.4556 35.3766 66.0 39.3 148.6 -0.0677 -0.2 2.1 Her X-1
263.0097 -24.7566 8.6 41.2 45.9 0.5880 1.3 0.7 GX 1+4
268.2689 -1.5076 5.8 21.4 72.7 0.4436 2.0 6.8 SW J1753.5-0127
270.2638 -25.0541 2.4 38.0 36.9 1.5310 4.8 1.9 GX 5-1
270.4527 -25.8189 4.8 38.6 36.1 0.7649 2.4 9.3 GRS 1758-258
273.9684 -13.8968 8.8 26.5 41.0 0.3284 1.3 8.7 GX 17+2
275.9865 -30.4141 7.1 41.1 26.4 0.5928 1.6 4.3 H1820-303
285.1766 -24.9314 7.1 34.3 14.7 0.4089 1.6 7.7 HT1900.1-2455
288.8155 10.9613 0.6 2.6 -117.8 3.8924 19.4 1.4 GRS 1915+105
299.6080 35.2127 0.5 28.4 -145.5 5.4371 23.7 1.1 Cyg X-1
308.1098 40.9600 41.7 36.8 -140.6 -0.0797 -0.3 0.4 Cyg X-3
262.9551 -33.8267 282.1 48.7 38.6 0.0373 0.0 1.8 GX 354-0
252.2004 16.6758 3.2 34.5 118.1 1.4003 3.6 ------ UNKNOWN
250.1226 41.8034 2.2 45.7 153.7 2.5726 5.2 ------ UNKNOWN
293.1456 -3.1550 2.3 14.0 -15.1 0.8766 5.0 ------ UNKNOWN
298.3009 17.1289 2.6 13.7 -114.0 0.8486 4.4 ------ UNKNOWN
290.7843 68.2829 3.0 59.0 -166.2 4.8624 3.9 ------ UNKNOWN
312.0076 65.9628 3.8 59.2 -156.2 4.6648 3.0 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-6.168000 14.060580
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.5362 35.5462 45.5 39.4 148.9 0.0248 0.3 12.8 Her X-1
263.0218 -24.7763 5.1 41.2 45.8 -0.2776 -2.3 2.0 GX 1+4
268.5338 -1.4980 23.6 21.2 72.3 -0.0302 -0.5 10.3 SW J1753.5-0127
270.2851 -25.1229 11.9 38.0 36.8 -0.0866 -1.0 2.6 GX 5-1
270.2466 -25.6967 5.9 38.5 36.4 -0.1760 -2.0 4.1 GRS 1758-258
273.8990 -14.1966 0.0 26.8 40.8 -0.0507 -0.8 11.4 GX 17+2
275.8308 -30.5165 0.0 41.2 26.5 0.1359 1.5 10.2 H1820-303
285.0719 -25.0056 29.9 34.4 14.9 0.0253 0.4 5.5 HT1900.1-2455
288.8165 10.9709 93.8 2.6 -117.9 -0.0059 -0.1 1.9 GRS 1915+105
299.4030 35.2688 7.4 28.4 -145.9 0.0904 1.6 10.0 Cyg X-1
308.1314 41.0233 5.9 36.9 -140.7 0.1482 2.0 4.3 Cyg X-3
262.9858 -33.9669 11.0 48.8 38.5 0.2545 1.1 7.9 GX 354-0
260.3006 49.0753 2.8 45.5 167.9 0.4299 4.2 ------ UNKNOWN
282.3334 8.3285 0.4 4.5 89.9 1.4447 28.4 ------ UNKNOWN
296.0779 -26.5146 2.4 36.9 -1.8 0.3341 4.9 ------ UNKNOWN
312.9743 43.8153 2.2 41.3 -139.1 0.4710 5.2 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
40.660600 274.660620
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.5064 35.2617 8.3 37.0 146.2 0.4821 1.4 5.4 Her X-1
263.1503 -24.7296 20.9 38.0 34.4 0.1694 0.5 7.8 GX 1+4
268.2900 -1.5156 3.2 17.1 60.9 0.7194 3.6 6.0 SW J1753.5-0127
270.3485 -25.0676 2.4 35.4 24.3 1.2979 4.9 3.6 GX 5-1
270.1744 -25.5960 3.7 35.9 24.3 0.8517 3.1 11.2 GRS 1758-258
274.1634 -14.1353 6.5 23.9 25.3 -0.3514 -1.8 10.9 GX 17+2
275.9610 -30.3725 8.9 39.2 14.1 0.3471 1.3 1.9 H1820-303
285.1218 -24.9455 6.4 33.4 0.8 0.4365 1.8 4.9 HT1900.1-2455
288.7740 10.9408 0.6 6.9 -107.5 3.4512 19.0 1.5 GRS 1915+105
299.5946 35.2037 0.5 31.2 -146.6 5.0064 23.1 0.2 Cyg X-1
308.0805 40.9092 16.4 39.8 -143.7 0.2420 0.7 2.9 Cyg X-3
262.8524 -33.8574 33.0 46.0 28.0 -0.1731 -0.3 6.9 GX 354-0
247.7490 9.3771 2.3 34.1 99.9 2.0200 5.0 ------ UNKNOWN
289.7773 49.8576 2.7 42.0 -167.4 1.2471 4.2 ------ UNKNOWN
306.0013 59.6219 2.9 54.3 -160.1 2.5520 4.0 ------ UNKNOWN
312.1862 -38.0610 2.4 54.1 -23.6 2.8249 4.7 ------ UNKNOWN
Plot creation:
Sun May 31 13:50:12 EDT 2015