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
326.7949 -8.2502 0.0108 33.2124 166.0428 1.1948487 17.702 TRIG_00540964
Foreground time interval of the image:
-2.160 15.757 (delta_t = 17.917 [sec])
Background time interval of the image:
-239.344 -2.160 (delta_t = 237.184 [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 -2.160 sec. to 44.716 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.41768 ( -0.0757698 0.0757357 )
Norm@50keV : 6.35024E-03 ( -0.000261003 0.000260892 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 38.04 using 59 PHA bins.
# Reduced chi-squared = 0.6673 for 57 degrees of freedom
# Null hypothesis probability = 9.749228e-01
Photon flux (15-150 keV) in 46.88 sec: 0.776503 ( -0.033725 0.0337986 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.86637e-06 ( -1.28163e-07 1.28571e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -2.160 sec. to 44.716 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.21116 ( -0.305762 0.239279 )
Epeak [keV] : 203.942 ( -90.8675 -203.942 )
Norm@50keV : 7.95523E-03 ( -0.00175417 0.00304636 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 36.54 using 59 PHA bins.
# Reduced chi-squared = 0.6524 for 56 degrees of freedom
# Null hypothesis probability = 9.795517e-01
Photon flux (15-150 keV) in 46.88 sec: 0.766775 ( -0.036162 0.036204 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.82612e-06 ( -1.41512e-07 1.40846e-07 ) ergs/cm2
Band function
Time interval is from -2.160 sec. to 44.716 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.906539 ( 0.90654 0.90654 )
beta : -1.50221 ( 1.50224 0.132544 )
Epeak [keV] : 85.7029 ( -85.7787 -85.7787 )
Norm@50keV : 1.23673E-02 ( -0.00619109 199.698 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 36.29 using 59 PHA bins.
# Reduced chi-squared = 0.6598 for 55 degrees of freedom
# Null hypothesis probability = 9.758121e-01
Photon flux (15-150 keV) in 46.88 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] : 16.7899 ( )
R^2/D10^2 : 5.92428E-02 ( )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 157.32 using 59 PHA bins.
# Reduced chi-squared = 2.7601 for 57 degrees of freedom
# Null hypothesis probability = 2.483853e-11
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.600e-07 1.315e-08
25- 50 7.008e-07 4.172e-08
50-150 1.405e-06 1.081e-07
15-150 2.266e-06 1.125e-07
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 ( )
Norm : 3.21581 (-0.132163 0.132144)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.64 using 59 PHA bins.
# Reduced chi-squared = 0.8358 for 57 degrees of freedom
# Null hypothesis probability = 8.068086e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.755e-07 1.725e-08
25- 50 7.223e-07 3.446e-08
50-150 1.584e-06 7.571e-08
15-150 2.682e-06 1.249e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 7.62491 (-1.17631 1.29174)
R1^2/D10^2 : 0.559027 (-0.218443 0.424428)
kT2 [keV] : 29.1208 (-4.14943 6.49002)
R2^2/D10^2 : 7.30508E-03 (-0.00361998 0.00538684)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 38.97 using 59 PHA bins.
# Reduced chi-squared = 0.7085 for 55 degrees of freedom
# Null hypothesis probability = 9.498492e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.115e-07 4.484e-08
25- 50 7.082e-07 8.345e-08
50-150 1.802e-06 2.782e-07
15-150 2.822e-06 3.500e-07
Peak spectrum fit
Power-law model
Time interval is from 27.908 sec. to 28.908 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.867029 ( -0.130419 0.126652 )
Norm@50keV : 2.94757E-02 ( -0.00221729 0.00220381 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.73 using 59 PHA bins.
# Reduced chi-squared = 1.136 for 57 degrees of freedom
# Null hypothesis probability = 2.248706e-01
Photon flux (15-150 keV) in 1 sec: 3.38299 ( -0.252647 0.25308 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.35118e-07 ( -2.60438e-08 2.61264e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 27.908 sec. to 28.908 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.626552 ( -0.530298 0.298732 )
Epeak [keV] : 336.866 ( -336.867 -336.867 )
Norm@50keV : 3.75311E-02 ( -0.00969608 0.0249829 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.00 using 59 PHA bins.
# Reduced chi-squared = 1.143 for 56 degrees of freedom
# Null hypothesis probability = 2.161362e-01
Photon flux (15-150 keV) in 1 sec: 3.35552 ( -0.25841 0.2586 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.32115e-07 ( -2.7255e-08 2.7025e-08 ) ergs/cm2
Band function
Time interval is from 27.908 sec. to 28.908 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 5.00000 ( -5 -5 )
beta : -0.867367 ( -0.126602 0.130537 )
Epeak [keV] : 16.2802 ( -16.2807 -16.2807 )
Norm@50keV : 2.12205E+04 ( -1524.2 3.9946e+06 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.72 using 59 PHA bins.
# Reduced chi-squared = 1.177 for 55 degrees of freedom
# Null hypothesis probability = 1.736026e-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] : 24.2887 (-2.44859 2.89461)
R^2/D10^2 : 9.21337E-02 (-0.0266888 0.0357245)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 90.83 using 59 PHA bins.
# Reduced chi-squared = 1.594 for 57 degrees of freedom
# Null hypothesis probability = 2.919803e-03
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 9.586e-09 1.511e-09
25- 50 5.357e-08 7.385e-09
50-150 2.352e-07 2.690e-08
15-150 2.984e-07 2.705e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 199.363 ( )
Norm : 13.4569 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 141.20 using 59 PHA bins.
# Reduced chi-squared = 2.4772 for 57 degrees of freedom
# Null hypothesis probability = 4.271256e-09
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.351e-08 3.095e-09
25- 50 6.446e-08 1.206e-08
50-150 1.414e-07 4.333e-08
15-150 2.393e-07 5.110e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 10.5036 (-2.89722 3.61307)
R1^2/D10^2 : 0.665833 (-0.352034 0.971861)
kT2 [keV] : 45.4732 (-12.854 53.1304)
R2^2/D10^2 : 1.22369E-02 (-0.0099696 0.0155384)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.09 using 59 PHA bins.
# Reduced chi-squared = 1.129 for 55 degrees of freedom
# Null hypothesis probability = 2.383340e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.815e-08 6.598e-09
25- 50 6.139e-08 2.547e-08
50-150 2.569e-07 1.201e-07
15-150 3.364e-07 1.409e-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: 1.66169 ( -0.158362 0.162001 )
Norm@50keV : 4.41575E-03 ( -0.000426495 0.000421924 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.90 using 59 PHA bins.
# Reduced chi-squared = 1.016 for 57 degrees of freedom
# Null hypothesis probability = 4.420268e-01
Photon flux (15-150 keV) in 17.92 sec: 0.578831 ( -0.0524536 0.0525162 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.351e-07 ( -7.50194e-08 7.58736e-08 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.16801 ( -0.746067 0.565227 )
Epeak [keV] : 80.0313 ( -24.3454 -80.0313 )
Norm@50keV : 8.02777E-03 ( -0.0038645 0.0115515 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.19 using 59 PHA bins.
# Reduced chi-squared = 1.003 for 56 degrees of freedom
# Null hypothesis probability = 4.677876e-01
Photon flux (15-150 keV) in 17.92 sec: 0.565720 ( -0.055242 0.055086 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.04984e-07 ( -8.47706e-08 8.47831e-08 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.11570 ( 1.1105 4.42288 )
beta : -2.15205 ( 2.14087 0.57374 )
Epeak [keV] : 75.1232 ( -73.8734 -73.8734 )
Norm@50keV : 8.62580E-03 ( -0.00441944 0 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.16 using 59 PHA bins.
# Reduced chi-squared = 1.021 for 55 degrees of freedom
# Null hypothesis probability = 4.313347e-01
Photon flux (15-150 keV) in 17.92 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 7.05372e-07 ( 0 0 ) ergs/cm2
S(25-50 keV) vs. S(50-100 keV) plot
S(25-50 keV) = 6.80e-07
S(50-100 keV) = 1.02e-06
T90 vs. Hardness ratio plot
T90 = 42.9199999570847 sec.
Hardness ratio (energy fluence ratio) = 1.5
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 1.52105
Count Ratio (50-100 keV) / (15-25 keV) = 1.22927
Mask shadow pattern
IMX = -6.353624374023616E-01, IMY = -1.579095246858080E-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:
-239.344000 -2.160000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.4610 35.4092 20.6 47.9 -2.8 0.2514 0.6 4.0 Her X-1
268.3308 -1.6084 2.8 31.3 -61.2 1.2494 4.1 9.6 SW J1753.5-0127
274.0263 -14.0587 1.9 32.9 -86.9 2.3702 6.1 1.8 GX 17+2
284.8408 -24.9035 52.1 35.8 -112.9 -0.0908 -0.2 10.7 HT1900.1-2455
288.7829 10.9876 2.5 9.4 -27.9 0.9342 4.6 2.7 GRS 1915+105
299.8220 35.1841 4.4 26.7 49.6 0.7866 2.6 11.4 Cyg X-1
308.1548 40.9209 3.4 33.6 60.3 1.4925 3.4 2.8 Cyg X-3
326.1810 38.3171 52.8 39.1 82.3 -0.2168 -0.2 0.5 Cyg X-2
279.4946 47.6687 2.5 42.2 27.8 2.1630 4.5 ------ UNKNOWN
278.2818 -12.0343 2.9 28.5 -89.7 1.1558 4.0 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-2.160000 15.756590
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.3659 35.4447 6.5 48.0 -2.8 0.1915 1.8 7.6 Her X-1
268.3823 -1.6521 4.3 31.3 -61.3 -0.1974 -2.7 12.0 SW J1753.5-0127
273.8558 -14.0054 7.2 32.9 -86.6 -0.1486 -1.6 8.9 GX 17+2
285.2305 -24.9383 5.4 35.7 -113.5 -0.1858 -2.2 10.6 HT1900.1-2455
288.5967 10.9252 8.5 9.6 -28.5 0.0700 1.4 11.9 GRS 1915+105
299.8513 35.2060 0.0 26.7 49.7 -0.0891 -1.2 12.8 Cyg X-1
308.1793 40.8995 7.2 33.6 60.3 -0.1676 -1.6 4.5 Cyg X-3
326.2321 38.4861 10.0 39.2 82.2 0.2590 1.2 10.3 Cyg X-2
326.7949 -8.2502 0.7 33.2 166.0 1.1947 17.7 ------ UNKNOWN
297.8656 7.2424 2.3 1.3 -126.0 0.2390 5.0 ------ UNKNOWN
244.7339 30.2551 2.6 54.2 -12.3 0.6813 4.5 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
75.556610 602.746000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
288.7195 10.8318 4.6 42.4 -42.3 1.3118 2.5 8.3 GRS 1915+105
299.6395 35.3343 6.0 50.5 -7.2 1.0768 1.9 8.3 Cyg X-1
307.9740 40.9690 4.7 52.2 3.7 1.8162 2.5 6.3 Cyg X-3
326.1184 38.4385 7.1 46.7 20.9 1.0293 1.6 7.4 Cyg X-2
2.7347 8.9973 2.6 39.7 86.8 5.1234 4.5 564.0 UNKNOWN
357.5043 -53.0926 3.7 51.3 178.5 2.3513 3.2 ------ UNKNOWN
350.3231 -62.9743 3.1 57.3 -170.8 4.4363 3.8 ------ UNKNOWN
286.3449 31.5644 2.9 55.5 -20.5 3.5827 4.0 ------ UNKNOWN
286.2531 29.3955 2.0 54.2 -22.6 4.2652 5.8 ------ UNKNOWN
323.5723 -66.1676 4.5 58.0 -156.8 4.5889 2.6 ------ UNKNOWN
308.1939 -58.9939 3.1 52.7 -146.4 3.8260 3.7 ------ UNKNOWN
287.5147 -25.9357 5.4 41.3 -98.7 3.0250 2.1 ------ UNKNOWN
Plot creation:
Sat May 30 17:44:47 EDT 2015