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
291.2929 13.7473 0.0160 6.2665 -131.2762 1.0441791 12.053 TRIG_00205096
Foreground time interval of the image:
29.976 74.901 (delta_t = 44.925 [sec])
Background time interval of the image:
-5.699 29.976 (delta_t = 35.675 [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 29.976 sec. to 246.944 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.66246 ( -0.0718946 0.0723175 )
Norm@50keV : 1.76374E-03 ( -6.77225e-05 6.74861e-05 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 41.73 using 59 PHA bins.
# Reduced chi-squared = 0.7320 for 57 degrees of freedom
# Null hypothesis probability = 9.356092e-01
Photon flux (15-150 keV) in 217 sec: 0.231256 ( -0.00926514 0.00930691 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.55522e-06 ( -1.43645e-07 1.44372e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 29.976 sec. to 246.944 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.52826 ( -0.294825 0.226227 )
Epeak [keV] : 179.257 ( -89.9138 -179.266 )
Norm@50keV : 2.05195E-03 ( -0.000343078 0.000786407 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 41.06 using 59 PHA bins.
# Reduced chi-squared = 0.7333 for 56 degrees of freedom
# Null hypothesis probability = 9.327338e-01
Photon flux (15-150 keV) in 217 sec: 0.228995 ( -0.010286 0.010129 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.51659e-06 ( -1.66764e-07 1.65159e-07 ) ergs/cm2
Band function
Time interval is from 29.976 sec. to 246.944 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.44411 ( 1.45197 1.45197 )
beta : -1.78366 ( 1.7731 0.168798 )
Epeak [keV] : 121.736 ( -127.33 -127.33 )
Norm@50keV : 2.27790E-03 ( -0.000524363 323612 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 40.81 using 59 PHA bins.
# Reduced chi-squared = 0.7419 for 55 degrees of freedom
# Null hypothesis probability = 9.230752e-01
Photon flux (15-150 keV) in 217 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] : 14.3555 ( )
R^2/D10^2 : 2.82837E-02 ( )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 197.99 using 59 PHA bins.
# Reduced chi-squared = 3.4735 for 57 degrees of freedom
# Null hypothesis probability = 1.850510e-17
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.665e-07 1.920e-08
25- 50 1.016e-06 4.698e-08
50-150 1.396e-06 1.000e-07
15-150 2.678e-06 1.172e-07
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 161.274 (-31 36.3739)
Norm : 0.934074 (-0.0406152 0.049841)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 43.15 using 59 PHA bins.
# Reduced chi-squared = 0.7570 for 57 degrees of freedom
# Null hypothesis probability = 9.125355e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 5.172e-07 3.201e-08
25- 50 9.685e-07 7.443e-08
50-150 1.968e-06 5.705e-07
15-150 3.454e-06 6.206e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 6.37190 (-1.00937 1.17972)
R1^2/D10^2 : 0.342926 (-0.151042 0.316029)
kT2 [keV] : 23.4357 (-2.90943 4.53192)
R2^2/D10^2 : 3.91665E-03 (-0.00189611 0.0026199)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.87 using 59 PHA bins.
# Reduced chi-squared = 0.9612 for 55 degrees of freedom
# Null hypothesis probability = 5.565594e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 5.193e-07 8.528e-08
25- 50 9.532e-07 8.485e-08
50-150 1.941e-06 2.379e-07
15-150 3.414e-06 3.396e-07
Peak spectrum fit
Power-law model
Time interval is from 90.160 sec. to 91.160 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.74258 ( -0.23061 0.241428 )
Norm@50keV : 6.83390E-03 ( -0.00105164 0.00102479 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.74 using 59 PHA bins.
# Reduced chi-squared = 0.9077 for 57 degrees of freedom
# Null hypothesis probability = 6.720645e-01
Photon flux (15-150 keV) in 1 sec: 0.921543 ( -0.121011 0.121028 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.30866e-08 ( -9.93168e-09 1.01377e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 90.160 sec. to 91.160 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.57445 ( -0.997501 0.589281 )
Epeak [keV] : 111.893 ( -112.323 -112.341 )
Norm@50keV : 8.49794E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.63 using 59 PHA bins.
# Reduced chi-squared = 0.9220 for 56 degrees of freedom
# Null hypothesis probability = 6.408367e-01
Photon flux (15-150 keV) in 1 sec: 0.916505 ( -0.123766 0.123235 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.20487e-08 ( -1.12944e-08 1.09588e-08 ) ergs/cm2
Band function
Time interval is from 90.160 sec. to 91.160 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 3.54334 ( -3.78383 -3.78383 )
beta : -1.82697 ( -0.376692 0.279418 )
Epeak [keV] : 22.9059 ( -23.0896 76.7253 )
Norm@50keV : 115.981 ( -115.663 626.026 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.23 using 59 PHA bins.
# Reduced chi-squared = 0.9314 for 55 degrees of freedom
# Null hypothesis probability = 6.195422e-01
Photon flux (15-150 keV) in 1 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 6.21159e-08 ( 0 0 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 11.2165 (-1.87546 2.30431)
R^2/D10^2 : 0.284154 (-0.140652 0.273263)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 67.72 using 59 PHA bins.
# Reduced chi-squared = 1.188 for 57 degrees of freedom
# Null hypothesis probability = 1.564983e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 7.497e-09 1.804e-09
25- 50 2.173e-08 4.535e-09
50-150 1.567e-08 5.291e-09
15-150 4.490e-08 7.740e-09
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 114.010 (-46.196 -113.518)
Norm : 3.96786 (-0.572045 0.828036)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.88 using 59 PHA bins.
# Reduced chi-squared = 0.9102 for 57 degrees of freedom
# Null hypothesis probability = 6.668753e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.035e-08 1.748e-09
25- 50 1.836e-08 3.655e-09
50-150 3.192e-08 1.831e-08
15-150 6.063e-08 2.235e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 6.26217 (-1.89293 2.28354)
R1^2/D10^2 : 1.73955 (-1.12796 4.74557)
kT2 [keV] : 24.2859 (-8.0623 28.0481)
R2^2/D10^2 : 1.25729E-02 (-0.0114328 0.0457162)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.02 using 59 PHA bins.
# Reduced chi-squared = 0.9277 for 55 degrees of freedom
# Null hypothesis probability = 6.273525e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.092e-08 5.699e-09
25- 50 1.782e-08 9.306e-09
50-150 3.322e-08 1.899e-08
15-150 6.196e-08 3.130e-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: 1.62476 ( -0.165822 0.169398 )
Norm@50keV : 1.32245E-03 ( -0.000136955 0.000135585 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.07 using 59 PHA bins.
# Reduced chi-squared = 0.9485 for 57 degrees of freedom
# Null hypothesis probability = 5.858180e-01
Photon flux (15-150 keV) in 44.92 sec: 0.171270 ( -0.0166683 0.0166845 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.53958e-07 ( -6.10867e-08 6.18652e-08 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.765744 ( -0.834676 0.705645 )
Epeak [keV] : 68.9210 ( -14.9496 88.1856 )
Norm@50keV : 3.69972E-03 ( -0.00207704 0.00604832 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.62 using 59 PHA bins.
# Reduced chi-squared = 0.8861 for 56 degrees of freedom
# Null hypothesis probability = 7.135320e-01
Photon flux (15-150 keV) in 44.92 sec: 0.164937 ( -0.017521 0.017459 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.18565e-07 ( -6.52777e-08 6.75911e-08 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.765618 ( -0.496582 0.826938 )
beta : -10.00000 ( 10 1.22569e-08 )
Epeak [keV] : 68.8998 ( -13.9074 88.0513 )
Norm@50keV : 3.70044E-03 ( -0.00207855 0.00271766 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.62 using 59 PHA bins.
# Reduced chi-squared = 0.9022 for 55 degrees of freedom
# Null hypothesis probability = 6.795856e-01
Photon flux (15-150 keV) in 44.92 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) = 9.47e-07
S(50-100 keV) = 1.20e-06
T90 vs. Hardness ratio plot
T90 = 141.124000012875 sec.
Hardness ratio (energy fluence ratio) = 1.26716
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 1.14709
Count Ratio (50-100 keV) / (15-25 keV) = 0.786678
Mask shadow pattern
IMX = -7.243973460855259E-02, IMY = 8.252560554271778E-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:
-5.699410 29.976000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.6166 35.3589 16.8 39.2 141.1 -0.0818 -0.7 7.8 Her X-1
263.1587 -24.8989 9.8 41.2 38.0 0.1512 1.2 12.3 GX 1+4
268.4731 -1.3029 19.5 21.1 65.3 -0.0384 -0.6 11.0 SW J1753.5-0127
270.2436 -25.2203 11.8 38.1 29.2 0.0973 1.0 8.8 GX 5-1
270.4661 -25.8845 3.9 38.6 28.4 0.2953 3.0 12.3 GRS 1758-258
274.0381 -14.0242 3.0 26.5 33.1 0.2745 3.9 2.0 GX 17+2
275.9255 -30.3674 191.9 41.0 18.8 0.0059 0.1 0.0 H1820-303
285.0662 -25.0056 5.4 34.3 7.3 0.1544 2.2 5.4 HT1900.1-2455
288.8299 10.9328 0.9 2.6 -125.1 0.6999 12.4 2.0 GRS 1915+105
299.5919 35.1797 0.6 28.4 -153.2 1.1811 20.3 1.3 Cyg X-1
308.2558 40.9753 36.9 36.9 -148.2 0.0244 0.3 6.7 Cyg X-3
326.1127 38.3964 9.5 45.7 -131.6 -0.2133 -1.2 5.3 Cyg X-2
263.0997 -33.7744 13.4 48.6 30.9 -0.1828 -0.9 6.6 GX 354-0
283.2776 -46.7947 2.2 56.2 7.4 1.7997 5.3 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
29.976000 74.900600
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.3641 35.4589 8.5 39.5 141.1 -0.2651 -1.3 8.4 Her X-1
263.0803 -24.8042 4.7 41.2 38.1 -0.5157 -2.4 5.2 GX 1+4
268.2020 -1.3229 0.0 21.3 65.6 0.1228 1.1 12.6 SW J1753.5-0127
270.2235 -25.0283 6.6 37.9 29.3 0.2861 1.7 4.5 GX 5-1
270.4656 -25.8811 4.1 38.6 28.4 -0.4698 -2.8 12.1 GRS 1758-258
274.0341 -14.0210 4.0 26.5 33.2 -0.3168 -2.9 1.9 GX 17+2
275.7774 -30.3037 4.2 41.0 19.0 0.4380 2.7 8.5 H1820-303
284.9768 -25.0731 8.3 34.4 7.4 -0.1689 -1.4 9.7 HT1900.1-2455
288.8861 10.9629 5.4 2.7 -124.8 -0.1957 -2.1 5.3 GRS 1915+105
299.6414 35.2671 33.6 28.5 -153.2 -0.0335 -0.3 4.7 Cyg X-1
308.2786 41.0739 0.0 37.0 -148.2 -0.2261 -1.8 10.5 Cyg X-3
326.3106 38.2843 9.2 45.8 -131.3 0.3563 1.3 6.9 Cyg X-2
263.0413 -33.7939 7.0 48.6 31.0 0.5763 1.7 3.6 GX 354-0
270.1920 65.2799 2.5 57.2 176.3 2.4234 4.7 ------ UNKNOWN
291.2929 13.7469 0.9 6.3 -131.3 1.0523 12.2 ------ UNKNOWN
296.6817 25.8005 2.6 19.0 -147.2 0.3796 4.5 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
101.500600 963.049800
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.5488 35.2283 12.3 39.4 138.7 -1.0830 -0.9 8.2 Her X-1
263.0012 -24.8230 4.9 47.5 44.8 4.4087 2.3 4.7 GX 1+4
268.4379 -1.5204 4.1 27.4 66.8 1.8588 2.8 5.8 SW J1753.5-0127
270.1972 -25.0789 5.5 44.0 37.1 2.3177 2.1 4.7 GX 5-1
270.3632 -25.7914 3.8 44.5 36.4 3.5798 3.1 4.4 GRS 1758-258
273.9858 -13.9812 1.3 32.6 41.5 5.2570 8.8 3.5 GX 17+2
275.9878 -30.3676 3.2 46.6 27.4 4.3835 3.6 3.3 H1820-303
285.1884 -25.0199 3.6 39.3 17.9 2.2671 3.2 10.2 HT1900.1-2455
288.7964 10.9484 0.4 3.8 50.0 13.6233 29.3 0.2 GRS 1915+105
299.5981 35.1966 0.2 22.7 -153.1 26.1477 50.1 0.5 Cyg X-1
308.2158 40.9618 12.2 30.9 -145.6 0.5126 0.9 4.8 Cyg X-3
326.1676 38.3144 6.3 39.4 -125.9 1.7317 1.8 0.5 Cyg X-2
282.3914 26.4431 2.4 15.1 157.1 1.9145 4.8 ------ UNKNOWN
291.2877 13.7781 1.4 0.0 37.6 4.0435 8.0 ------ UNKNOWN
314.8942 -22.6095 3.2 43.1 -23.6 2.7975 3.6 ------ UNKNOWN
304.6803 72.3542 4.1 59.1 -166.2 10.0977 2.9 ------ UNKNOWN
332.6325 -1.2128 3.7 43.6 -64.1 8.8099 3.2 ------ UNKNOWN
Plot creation:
Sun May 31 13:43:23 EDT 2015