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
98.4685 -19.8995 0.0090 1.9149 59.9138 1.5992914 21.485 TRIG_00574935
Foreground time interval of the image:
21.096 72.901 (delta_t = 51.805 [sec])
Background time interval of the image:
-239.000 21.096 (delta_t = 260.096 [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)
The mask-weighted light curves based on cleaned DPHs
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 21.096 sec. to 117.736 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.24462 ( -0.136883 0.142607 )
Norm@50keV : 1.19428E-03 ( -0.000113898 0.000112442 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.47 using 59 PHA bins.
# Reduced chi-squared = 1.008 for 57 degrees of freedom
# Null hypothesis probability = 4.577727e-01
Photon flux (15-150 keV) in 96.64 sec: 0.202474 ( -0.0136141 0.0136199 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.09246e-06 ( -8.71246e-08 8.86601e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 21.096 sec. to 117.736 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.71234 ( -0.668119 0.285758 )
Epeak [keV] : 20.7575 ( -19.2289 12.4732 )
Norm@50keV : 2.50313E-03 ( -0.000999266 0.00385717 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.94 using 59 PHA bins.
# Reduced chi-squared = 0.9811 for 56 degrees of freedom
# Null hypothesis probability = 5.148766e-01
Photon flux (15-150 keV) in 96.64 sec: 0.197522 ( -0.01449 0.014539 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.02553e-06 ( -1.04878e-07 1.11861e-07 ) ergs/cm2
Band function
Time interval is from 21.096 sec. to 117.736 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.716847 ( -4.97158 -2.6122 )
beta : -2.42347 ( -0.243507 0.197334 )
Epeak [keV] : 23.6622 ( -5.31119 3.67469 )
Norm@50keV : 0.180415 ( -0.177758 246.875 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.36 using 59 PHA bins.
# Reduced chi-squared = 0.9702 for 55 degrees of freedom
# Null hypothesis probability = 5.373922e-01
Photon flux (15-150 keV) in 96.64 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 1.05146e-06 ( -1.05079e-06 -9.36674e-08 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 8.39447 (-0.674078 0.733848)
R^2/D10^2 : 0.176062 (-0.0506161 0.0714352)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 93.59 using 59 PHA bins.
# Reduced chi-squared = 1.642 for 57 degrees of freedom
# Null hypothesis probability = 1.613326e-03
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.242e-07 2.464e-08
25- 50 4.258e-07 3.605e-08
50-150 1.307e-07 2.942e-08
15-150 7.807e-07 6.586e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 44.4225 (-7.62876 10.3148)
Norm : 1.21022 (-0.156157 0.185171)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.87 using 59 PHA bins.
# Reduced chi-squared = 0.9801 for 57 degrees of freedom
# Null hypothesis probability = 5.176518e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.774e-07 2.513e-08
25- 50 3.812e-07 2.890e-08
50-150 3.295e-07 7.118e-08
15-150 9.880e-07 9.026e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 5.06361 (-0.927608 1.02402)
R1^2/D10^2 : 0.980507 (-0.48399 1.20516)
kT2 [keV] : 15.8227 (-3.19317 5.51811)
R2^2/D10^2 : 9.43488E-03 (-0.00674936 0.0130171)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.78 using 59 PHA bins.
# Reduced chi-squared = 0.9778 for 55 degrees of freedom
# Null hypothesis probability = 5.213530e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.896e-07 8.925e-08
25- 50 3.605e-07 1.061e-07
50-150 3.506e-07 1.875e-07
15-150 1.001e-06 2.827e-07
Peak spectrum fit
Power-law model
Time interval is from 59.412 sec. to 60.412 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.83598 ( -0.417389 0.46419 )
Norm@50keV : 3.44213E-03 ( -0.00105243 0.00100201 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 75.13 using 59 PHA bins.
# Reduced chi-squared = 1.318 for 57 degrees of freedom
# Null hypothesis probability = 5.406302e-02
Photon flux (15-150 keV) in 1 sec: 0.481098 ( -0.115906 0.115907 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.1656e-08 ( -9.29286e-09 9.75795e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 59.412 sec. to 60.412 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.34864 ( -2.45037 0.830929 )
Epeak [keV] : 54.9362 ( )
Norm@50keV : 6.68349E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 74.92 using 59 PHA bins.
# Reduced chi-squared = 1.338 for 56 degrees of freedom
# Null hypothesis probability = 4.648464e-02
Photon flux (15-150 keV) in 1 sec: 0.474833 ( -0.117911 0.116662 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.9971e-08 ( -1.00648e-08 1.10425e-08 ) ergs/cm2
Band function
Time interval is from 59.412 sec. to 60.412 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 4.96804 ( -4.96804 -4.96804 )
beta : -1.94846 ( -0.749614 0.470682 )
Epeak [keV] : 21.1506 ( -21.1506 8.88648 )
Norm@50keV : 1404.48 ( -335.786 4.62677e+06 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 74.42 using 59 PHA bins.
# Reduced chi-squared = 1.353 for 55 degrees of freedom
# Null hypothesis probability = 4.165341e-02
Photon flux (15-150 keV) in 1 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 3.01494e-08 ( 0 0 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 10.5627 (-2.77689 3.67023)
R^2/D10^2 : 0.188586 (-0.126671 0.396013)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 78.42 using 59 PHA bins.
# Reduced chi-squared = 1.376 for 57 degrees of freedom
# Null hypothesis probability = 3.147505e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.356e-09 2.313e-09
25- 50 1.168e-08 5.004e-09
50-150 7.126e-09 4.405e-09
15-150 2.316e-08 1.335e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 84.8498 (-45.8286 -84.8498)
Norm : 2.23930 (-0.639354 1.01428)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 74.91 using 59 PHA bins.
# Reduced chi-squared = 1.314 for 57 degrees of freedom
# Null hypothesis probability = 5.597629e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 5.830e-09 2.413e-09
25- 50 9.731e-09 5.615e-09
50-150 1.428e-08 1.166e-08
15-150 2.984e-08 1.892e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 4.54760 (-2.6812 6.74501)
R1^2/D10^2 : 2.64848 (-2.45911 226.298)
kT2 [keV] : 15.7574 (-5.86376 -15.7555)
R2^2/D10^2 : 3.34617E-02 (-0.033265 0.187539)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 74.78 using 59 PHA bins.
# Reduced chi-squared = 1.360 for 55 degrees of freedom
# Null hypothesis probability = 3.920740e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 6.062e-09 3.478e-09
25- 50 9.383e-09 4.817e-09
50-150 1.240e-08 7.550e-09
15-150 2.785e-08 1.510e-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: 2.21794 ( -0.130461 0.135542 )
Norm@50keV : 1.69870E-03 ( -0.000155113 0.000153283 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.99 using 59 PHA bins.
# Reduced chi-squared = 1.105 for 57 degrees of freedom
# Null hypothesis probability = 2.726709e-01
Photon flux (15-150 keV) in 51.8 sec: 0.283905 ( -0.0186725 0.0186798 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.29458e-07 ( -6.44729e-08 6.5541e-08 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.47029 ( -0.706973 0.524608 )
Epeak [keV] : 26.8386 ( )
Norm@50keV : 4.84525E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.19 using 59 PHA bins.
# Reduced chi-squared = 1.039 for 56 degrees of freedom
# Null hypothesis probability = 3.945346e-01
Photon flux (15-150 keV) in 51.8 sec: 0.274795 ( -0.019815 0.019865 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.5972e-07 ( -7.66847e-08 8.24138e-08 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.877259 ( -1.33634 5.01643 )
beta : -2.53991 ( -0.376495 0.251249 )
Epeak [keV] : 26.3145 ( -4.37004 4.2456 )
Norm@50keV : 0.252705 ( -0.24864 178.093 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.90 using 59 PHA bins.
# Reduced chi-squared = 0.9800 for 55 degrees of freedom
# Null hypothesis probability = 5.167897e-01
Photon flux (15-150 keV) in 51.8 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 7.80196e-07 ( -7.79833e-07 -6.93084e-08 ) ergs/cm2
S(25-50 keV) vs. S(50-100 keV) plot
S(25-50 keV) = 3.49e-07
S(50-100 keV) = 2.95e-07
T90 vs. Hardness ratio plot
T90 = 73.2159999608994 sec.
Hardness ratio (energy fluence ratio) = 0.845272
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 0.918099
Count Ratio (50-100 keV) / (15-25 keV) = 0.362039
Mask shadow pattern
IMX = 1.676086241716447E-02, IMY = -2.893002242861716E-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:
-239.000000 21.096000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
83.6423 22.0215 0.6 44.2 153.2 10.7513 18.8 0.7 Crab
135.5930 -40.5239 1.8 37.0 -51.3 1.9653 6.5 3.5 Vela X-1
64.4819 2.7856 2.7 41.5 113.5 3.3406 4.3 ------ UNKNOWN
76.8144 -58.0095 2.4 42.6 13.7 1.6351 4.8 ------ UNKNOWN
83.7341 -59.1164 2.9 41.8 8.2 1.2475 3.9 ------ UNKNOWN
92.4763 -40.7359 2.5 22.7 11.1 0.9097 4.7 ------ UNKNOWN
107.4238 -38.7993 2.6 20.7 -20.3 0.8678 4.5 ------ UNKNOWN
110.9571 -39.2946 2.2 22.2 -26.7 0.9997 5.4 ------ UNKNOWN
119.5836 -8.9615 2.5 21.2 -120.2 0.9266 4.7 ------ UNKNOWN
129.7111 21.4686 3.2 49.7 -147.6 1.8640 3.6 ------ UNKNOWN
139.3189 7.1541 2.3 46.5 -125.1 4.4598 4.9 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
21.096000 72.900600
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
83.5141 22.0594 16.7 44.3 153.0 0.1303 0.7 7.2 Crab
135.5557 -40.6032 10.4 37.0 -51.2 -0.1413 -1.1 3.2 Vela X-1
88.0494 -9.1935 2.1 15.4 123.7 0.4175 5.5 ------ UNKNOWN
98.4686 -19.8995 0.5 1.9 59.9 1.5989 21.5 ------ UNKNOWN
116.8525 -33.9556 2.3 20.9 -45.8 0.3908 5.0 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
97.700600 963.157200
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
83.6363 22.0199 0.5 44.3 145.9 35.3048 22.6 0.4 Crab
135.5422 -40.5441 2.0 37.7 -62.8 7.0128 5.7 0.9 Vela X-1
61.8123 -59.8268 3.4 47.7 9.6 3.3336 3.4 ------ UNKNOWN
107.4301 19.4387 2.5 40.3 178.8 3.1086 4.6 ------ UNKNOWN
112.5538 31.5532 3.1 53.2 -179.3 5.7331 3.7 ------ UNKNOWN
114.3916 -41.6078 2.8 25.6 -42.7 1.9926 4.1 ------ UNKNOWN
135.1635 -75.6264 3.8 58.9 -24.3 10.8253 3.0 ------ UNKNOWN
142.1600 -18.9200 4.7 41.1 -98.0 7.6233 2.5 ------ UNKNOWN
141.2322 0.3896 2.6 46.5 -125.0 10.2383 4.4 ------ UNKNOWN
141.0129 3.6796 2.9 48.0 -129.0 8.7098 3.9 ------ UNKNOWN
Plot creation:
Sat May 30 15:22:32 EDT 2015