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
285.9395 45.7061 0.0183 27.1393 47.5341 0.1030458 10.559 TRIG_00440955
Foreground time interval of the image:
0.024 0.296 (delta_t = 0.272 [sec])
Background time interval of the image:
-239.256 0.024 (delta_t = 239.280 [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
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 0.256000
8 ms binning
From T100_start-3 s to T100_start+3 s
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 0.256000
2 ms binning
From T100_start-1 s to T100_start+1 s
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 0.256000
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 0.024 sec. to 0.296 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.04639 ( -0.266018 0.258725 )
Norm@50keV : 1.94644E-02 ( -0.00372087 0.00370128 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 71.54 using 59 PHA bins.
# Reduced chi-squared = 1.255 for 57 degrees of freedom
# Null hypothesis probability = 9.314857e-02
Photon flux (15-150 keV) in 0.272 sec: 2.24707 ( -0.437678 0.440501 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.63421e-08 ( -1.07856e-08 1.08112e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.024 sec. to 0.296 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.927587 ( -1.80365 1.23498 )
Epeak [keV] : 95.8109 ( -19.867 50.9007 )
Norm@50keV : 0.118021 ( -0.117787 0.341803 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.83 using 59 PHA bins.
# Reduced chi-squared = 1.122 for 56 degrees of freedom
# Null hypothesis probability = 2.471778e-01
Photon flux (15-150 keV) in 0.272 sec: 2.17799 ( -0.22121 0.44273 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.79831e-08 ( -1.12953e-08 1.12627e-08 ) ergs/cm2
Band function
Time interval is from 0.024 sec. to 0.296 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.921023 ( -0.937382 1.56061 )
beta : -10.0000 ( 10 3.19744e-14 )
Epeak [keV] : 95.9415 ( -19.9673 50.7969 )
Norm@50keV : 0.117307 ( -0.117307 0.342688 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.83 using 59 PHA bins.
# Reduced chi-squared = 1.142 for 55 degrees of freedom
# Null hypothesis probability = 2.186210e-01
Photon flux (15-150 keV) in 0.272 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 5.80067e-08 ( 0 0 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 23.5421 (-4.10039 4.91877)
R^2/D10^2 : 7.31014E-02 (-0.0337118 0.0614257)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.88 using 59 PHA bins.
# Reduced chi-squared = 1.103 for 57 degrees of freedom
# Null hypothesis probability = 2.760425e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.974e-09 7.343e-10
25- 50 1.085e-08 3.612e-09
50-150 4.487e-08 1.503e-08
15-150 5.770e-08 1.446e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 ( )
Norm : 9.33744 (-1.8393 1.83912)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 79.84 using 59 PHA bins.
# Reduced chi-squared = 1.401 for 57 degrees of freedom
# Null hypothesis probability = 2.460162e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 6.328e-09 3.691e-09
25- 50 1.217e-08 7.196e-09
50-150 2.670e-08 1.549e-08
15-150 4.520e-08 2.666e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 7.95828 (-7.93751 191.751)
R1^2/D10^2 : 0.373020 (-0.377606 -0.377606)
kT2 [keV] : 25.2693 (-5.33605 -25.2677)
R2^2/D10^2 : 5.47531E-02 (-0.0547975 0.0695123)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.24 using 59 PHA bins.
# Reduced chi-squared = 1.132 for 55 degrees of freedom
# Null hypothesis probability = 2.342470e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.800e-09 1.605e-09
25- 50 1.138e-08 6.450e-09
50-150 4.481e-08 2.671e-08
15-150 5.899e-08 3.366e-08
Peak spectrum fit
Power-law model
Time interval is from -0.338 sec. to 0.662 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.710471 ( -0.528628 0.441991 )
Norm@50keV : 5.98976E-03 ( -0.00184341 0.00174683 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 45.31 using 59 PHA bins.
# Reduced chi-squared = 0.7950 for 57 degrees of freedom
# Null hypothesis probability = 8.678575e-01
Photon flux (15-150 keV) in 1 sec: 0.691810 ( -0.192524 0.196157 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.27709e-08 ( -1.92658e-08 1.93668e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.338 sec. to 0.662 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 5.08966E-02 ( -2.64219 -0.0477609 )
Epeak [keV] : 176.239 ( -176.086 -176.086 )
Norm@50keV : 1.14908E-02 ( -0.00707766 0.118108 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.90 using 59 PHA bins.
# Reduced chi-squared = 0.8017 for 56 degrees of freedom
# Null hypothesis probability = 8.562870e-01
Photon flux (15-150 keV) in 1 sec: 0.678882 ( -0.193244 0.198294 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.09501e-08 ( -2.12456e-08 2.02015e-08 ) ergs/cm2
Band function
Time interval is from -0.338 sec. to 0.662 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 5.00000 ( -4.96474 -4.96474 )
beta : -0.949646 ( -1.13608 0.615288 )
Epeak [keV] : 37.3951 ( -37.3954 31.8883 )
Norm@50keV : 38.1978 ( -9.66454 854702 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 43.67 using 59 PHA bins.
# Reduced chi-squared = 0.7941 for 55 degrees of freedom
# Null hypothesis probability = 8.642886e-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] : 26.1426 (-8.1925 16.8613)
R^2/D10^2 : 1.57436E-02 (-0.0157198 0.03509)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 46.03 using 59 PHA bins.
# Reduced chi-squared = 0.8075 for 57 degrees of freedom
# Null hypothesis probability = 8.505126e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.825e-09 1.143e-09
25- 50 1.058e-08 6.375e-09
50-150 5.322e-08 3.163e-08
15-150 6.563e-08 4.037e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 ( )
Norm : 2.82574 (-0.831016 0.830905)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.56 using 59 PHA bins.
# Reduced chi-squared = 0.9572 for 57 degrees of freedom
# Null hypothesis probability = 5.671242e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 7.035e-09 4.373e-09
25- 50 1.353e-08 8.295e-09
50-150 2.968e-08 1.840e-08
15-150 5.025e-08 3.131e-08
Double BB
R1^2/D10^2 : 4.10052E-04 ( )
kT2 [keV] : 14.7060 (-14.7075 17.3259)
R2^2/D10^2 : 6.17424E-02 (-0.0617179 -0.0617179)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.09 using 59 PHA bins.
#Fit statistic : Chi-Squared = 43.91 using 59 PHA bins.
#Fit statistic : Chi-Squared = 43.90 using 59 PHA bins.
# Reduced chi-squared = 0.8016 for 55 degrees of freedom
# Reduced chi-squared = 0.7984 for 55 degrees of freedom
# Reduced chi-squared = 0.7982 for 55 degrees of freedom
# Null hypothesis probability = 8.540219e-01
# Null hypothesis probability = 8.583971e-01
# Null hypothesis probability = 8.587026e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.134e-09 2.289e-09
25- 50 1.276e-08 8.865e-09
50-150 5.597e-08 2.904e-08
15-150 7.187e-08 3.898e-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: 1.04639 ( -0.266018 0.258725 )
Norm@50keV : 1.94644E-02 ( -0.00372087 0.00370128 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 71.54 using 59 PHA bins.
# Reduced chi-squared = 1.255 for 57 degrees of freedom
# Null hypothesis probability = 9.314857e-02
Photon flux (15-150 keV) in 0.272 sec: 2.24707 ( -0.437678 0.440501 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.63421e-08 ( -1.07856e-08 1.08112e-08 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.927587 ( -1.80365 1.23498 )
Epeak [keV] : 95.8109 ( -19.867 50.9007 )
Norm@50keV : 0.118021 ( -0.117787 0.341803 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.83 using 59 PHA bins.
# Reduced chi-squared = 1.122 for 56 degrees of freedom
# Null hypothesis probability = 2.471778e-01
Photon flux (15-150 keV) in 0.272 sec: 2.17799 ( -0.22121 0.44273 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.79831e-08 ( -1.12953e-08 1.12627e-08 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.921023 ( -0.937382 1.56061 )
beta : -10.0000 ( 10 3.55271e-15 )
Epeak [keV] : 95.9415 ( -19.9673 50.7969 )
Norm@50keV : 0.117307 ( -0.117307 0.342688 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.83 using 59 PHA bins.
# Reduced chi-squared = 1.142 for 55 degrees of freedom
# Null hypothesis probability = 2.186210e-01
Photon flux (15-150 keV) in 0.272 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 5.80067e-08 ( 0 0 ) ergs/cm2
S(25-50 keV) vs. S(50-100 keV) plot
S(25-50 keV) = 1.08e-08
S(50-100 keV) = 2.08e-08
T90 vs. Hardness ratio plot
T90 = 0.24399995803833 sec.
Hardness ratio (energy fluence ratio) = 1.92593
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 3.83062
Count Ratio (50-100 keV) / (15-25 keV) = 4.88687
Mask shadow pattern
IMX = 3.460763347837418E-01, IMY = -3.781281415607399E-01
TIME vs. PHA plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 0.256000
TIME vs. DetID plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 0.256000
100 us light curve (15-350 keV)
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 0.256000
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:
-239.256000 0.024000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.4556 35.2211 5.5 37.6 1.8 -0.6155 -2.1 7.3 Her X-1
268.5421 -1.3839 0.0 31.7 -69.2 0.3098 0.9 11.2 SW J1753.5-0127
274.1522 -14.0282 8.0 38.1 -90.7 -1.0463 -1.4 8.5 GX 17+2
288.8019 10.9382 0.6 9.3 -94.2 3.7388 18.7 0.5 GRS 1915+105
299.5910 35.2322 2.3 17.0 76.9 1.1889 5.0 1.8 Cyg X-1
308.0627 40.9638 2.3 25.2 85.8 1.5659 5.1 2.3 Cyg X-3
326.2311 38.3214 7.8 34.4 107.8 0.7757 1.5 2.8 Cyg X-2
242.3321 3.6175 2.7 51.9 -42.3 4.9761 4.4 ------ UNKNOWN
242.0702 3.6533 3.2 52.2 -42.1 4.4556 3.8 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
0.024000 0.296000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.3331 35.2434 6.3 37.7 1.8 -0.0185 -1.9 8.5 Her X-1
268.2618 -1.4118 7.7 32.0 -68.9 -0.0153 -1.5 6.8 SW J1753.5-0127
274.0472 -14.0031 27.9 38.2 -90.6 0.0070 0.4 3.1 GX 17+2
288.8512 10.7416 0.0 9.4 -95.0 -0.0141 -1.9 12.6 GRS 1915+105
299.4988 35.3334 23.2 17.1 76.6 0.0039 0.5 9.1 Cyg X-1
308.3618 40.9923 5.7 25.4 86.2 0.0207 2.0 11.6 Cyg X-3
326.1416 38.1167 0.0 34.3 108.1 -0.0006 -0.0 12.4 Cyg X-2
285.9395 45.7061 1.1 27.1 47.5 0.1031 10.6 ------ UNKNOWN
338.3057 -0.1028 2.5 48.3 166.8 0.0903 4.6 ------ UNKNOWN
263.4171 21.8690 2.0 27.9 -20.8 0.0419 5.8 ------ UNKNOWN
229.2339 27.4189 1.6 58.6 -10.4 0.2825 7.1 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
61.644600 962.789600
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.6623 35.2444 12.5 25.7 -25.8 -0.4507 -0.9 11.6 Her X-1
288.8000 10.9387 0.8 34.8 -107.9 12.3897 13.7 0.4 GRS 1915+105
299.5806 35.1966 1.7 14.7 -152.3 3.2026 6.8 0.6 Cyg X-1
308.1409 40.9893 1.6 16.8 175.4 3.6373 7.0 2.6 Cyg X-3
326.0331 38.3131 4.7 30.4 166.7 1.6472 2.5 6.5 Cyg X-2
220.2148 21.2871 3.1 58.1 -14.3 9.5353 3.8 ------ UNKNOWN
220.7184 18.6301 3.0 59.6 -17.0 12.2976 3.9 ------ UNKNOWN
259.3733 11.5397 2.7 40.9 -61.0 6.4081 4.2 ------ UNKNOWN
251.3405 9.1650 3.9 47.0 -52.9 6.8963 3.0 ------ UNKNOWN
241.7345 9.7991 4.0 52.0 -42.3 8.3374 2.9 ------ UNKNOWN
278.9798 5.1757 3.4 41.0 -92.4 7.3041 3.4 ------ UNKNOWN
Plot creation:
Sat May 30 23:19:12 EDT 2015