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
224.4081 28.1904 0.0235 21.8715 -167.1336 2.8993747 8.198 TRIG_00557845
Foreground time interval of the image:
-7.040 62.440 (delta_t = 69.480 [sec])
Background time interval of the image:
-12.099 -7.040 (delta_t = 5.059 [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 -7.040 sec. to 62.440 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.27243 ( -0.0770147 0.076613 )
Norm@50keV : 3.66508E-03 ( -0.000155595 0.000155594 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.61 using 59 PHA bins.
# Reduced chi-squared = 1.046 for 57 degrees of freedom
# Null hypothesis probability = 3.809974e-01
Photon flux (15-150 keV) in 69.48 sec: 0.435110 ( -0.0192579 0.0192867 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.53376e-06 ( -1.188e-07 1.19225e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -7.040 sec. to 62.440 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.00996 ( -0.305325 0.283087 )
Epeak [keV] : 201.993 ( -80.6298 -201.993 )
Norm@50keV : 4.88108E-03 ( -0.00113392 0.00185981 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.12 using 59 PHA bins.
# Reduced chi-squared = 1.020 for 56 degrees of freedom
# Null hypothesis probability = 4.331853e-01
Photon flux (15-150 keV) in 69.48 sec: 0.429053 ( -0.0203 0.020303 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.48761e-06 ( -1.30685e-07 1.30004e-07 ) ergs/cm2
Band function
Time interval is from -7.040 sec. to 62.440 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 4.98582 ( -14.6108 -4.98582 )
beta : -1.34666 ( -0.0883163 0.0867872 )
Epeak [keV] : 26.6905 ( -3.9019 3.01204 )
Norm@50keV : 208.858 ( -8.84486 348.196 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.45 using 59 PHA bins.
# Reduced chi-squared = 0.9536 for 55 degrees of freedom
# Null hypothesis probability = 5.726515e-01
Photon flux (15-150 keV) in 69.48 sec: 0.427601 ( 6.5724 -0.020242 ) 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] : 18.0098 ( )
R^2/D10^2 : 2.72583E-02 ( )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 162.21 using 59 PHA bins.
# Reduced chi-squared = 2.8458 for 57 degrees of freedom
# Null hypothesis probability = 4.931159e-12
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.230e-07 1.049e-08
25- 50 5.689e-07 3.411e-08
50-150 1.340e-06 1.136e-07
15-150 2.032e-06 1.153e-07
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 ( )
Norm : 1.81366 (-0.0779261 0.0779085)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 94.32 using 59 PHA bins.
# Reduced chi-squared = 1.655 for 57 degrees of freedom
# Null hypothesis probability = 1.375806e-03
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.137e-07 1.577e-08
25- 50 6.035e-07 3.078e-08
50-150 1.324e-06 6.635e-08
15-150 2.241e-06 1.122e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 8.32418 (-1.21207 1.33003)
R1^2/D10^2 : 0.224167 (-0.0812204 0.144919)
kT2 [keV] : 32.8909 (-5.11187 8.27277)
R2^2/D10^2 : 3.03544E-03 (-0.00153963 0.00234276)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.13 using 59 PHA bins.
# Reduced chi-squared = 0.9659 for 55 degrees of freedom
# Null hypothesis probability = 5.465435e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.343e-07 3.960e-08
25- 50 5.912e-07 7.181e-08
50-150 1.690e-06 3.474e-07
15-150 2.516e-06 4.235e-07
Peak spectrum fit
Power-law model
Time interval is from 4.532 sec. to 5.532 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.19219 ( -0.162329 0.160961 )
Norm@50keV : 1.46995E-02 ( -0.00143963 0.00143909 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 75.22 using 59 PHA bins.
# Reduced chi-squared = 1.320 for 57 degrees of freedom
# Null hypothesis probability = 5.329731e-02
Photon flux (15-150 keV) in 1 sec: 1.72355 ( -0.170769 0.170932 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.49462e-07 ( -1.6433e-08 1.65845e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 4.532 sec. to 5.532 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.205581 ( -0.8767 0.718093 )
Epeak [keV] : 93.7834 ( -23.2859 108.394 )
Norm@50keV : 4.48588E-02 ( -0.0245607 0.0729327 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 69.39 using 59 PHA bins.
# Reduced chi-squared = 1.239 for 56 degrees of freedom
# Null hypothesis probability = 1.078284e-01
Photon flux (15-150 keV) in 1 sec: 1.66005 ( -0.17812 0.17761 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.39166e-07 ( -1.8433e-08 1.8482e-08 ) ergs/cm2
Band function
Time interval is from 4.532 sec. to 5.532 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.380712 ( -1.16335 -0.399176 )
beta : -1.72864 ( 1.72844 0.446329 )
Epeak [keV] : 68.5772 ( -31.6043 84.4986 )
Norm@50keV : 0.100050 ( -0.108468 73.3631 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 68.38 using 59 PHA bins.
# Reduced chi-squared = 1.243 for 55 degrees of freedom
# Null hypothesis probability = 1.062015e-01
Photon flux (15-150 keV) in 1 sec: 1.65324 ( 5.34676 -0.17769 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.40471e-07 ( -1.40464e-07 -1.776e-08 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 17.3581 (-1.96857 2.30332)
R^2/D10^2 : 0.129992 (-0.0441903 0.0643225)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 77.67 using 59 PHA bins.
# Reduced chi-squared = 1.363 for 57 degrees of freedom
# Null hypothesis probability = 3.576060e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 7.930e-09 1.428e-09
25- 50 3.567e-08 5.295e-09
50-150 7.723e-08 1.393e-08
15-150 1.208e-07 1.671e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 ( )
Norm : 7.04906 (-0.701456 0.701434)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 85.00 using 59 PHA bins.
# Reduced chi-squared = 1.491 for 57 degrees of freedom
# Null hypothesis probability = 9.504974e-03
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.756e-08 9.715e-09
25- 50 3.377e-08 1.830e-08
50-150 7.406e-08 4.032e-08
15-150 1.254e-07 6.307e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 10.9322 (-4.37675 4.25864)
R1^2/D10^2 : 0.373935 (-0.190793 0.841384)
kT2 [keV] : 33.6732 (-28.7778 -35.3908)
R2^2/D10^2 : 9.53462E-03 (-0.00732976 0.0532516)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 68.29 using 59 PHA bins.
# Reduced chi-squared = 1.242 for 55 degrees of freedom
# Null hypothesis probability = 1.075590e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.090e-08 6.175e-09
25- 50 3.629e-08 2.017e-08
50-150 9.445e-08 4.844e-08
15-150 1.416e-07 6.978e-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: 1.27243 ( -0.0770147 0.076613 )
Norm@50keV : 3.66508E-03 ( -0.000155595 0.000155594 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.61 using 59 PHA bins.
# Reduced chi-squared = 1.046 for 57 degrees of freedom
# Null hypothesis probability = 3.809974e-01
Photon flux (15-150 keV) in 69.48 sec: 0.435110 ( -0.0192579 0.0192867 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.53376e-06 ( -1.188e-07 1.19225e-07 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.00996 ( -0.305325 0.283087 )
Epeak [keV] : 201.993 ( -80.6298 -201.993 )
Norm@50keV : 4.88108E-03 ( -0.00113392 0.00185981 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.12 using 59 PHA bins.
# Reduced chi-squared = 1.020 for 56 degrees of freedom
# Null hypothesis probability = 4.331853e-01
Photon flux (15-150 keV) in 69.48 sec: 0.429053 ( -0.0203 0.020303 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.48761e-06 ( -1.30685e-07 1.30004e-07 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 4.98582 ( -5.18805 -4.98582 )
beta : -1.34666 ( -0.0883163 0.0867872 )
Epeak [keV] : 26.6905 ( -3.9019 3.01204 )
Norm@50keV : 208.858 ( -8.84486 348.196 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.45 using 59 PHA bins.
# Reduced chi-squared = 0.9536 for 55 degrees of freedom
# Null hypothesis probability = 5.726515e-01
Photon flux (15-150 keV) in 69.48 sec: 0.427601 ( 6.5724 -0.020242 ) 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) = 5.55e-07
S(50-100 keV) = 9.19e-07
T90 vs. Hardness ratio plot
T90 = 47.7239999175072 sec.
Hardness ratio (energy fluence ratio) = 1.65586
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 1.6063
Count Ratio (50-100 keV) / (15-25 keV) = 1.37281
Mask shadow pattern
IMX = -3.913418130255893E-01, IMY = 8.938769030632743E-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:
-12.099400 -7.040000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.2499 35.4702 0.0 7.0 -45.2 -0.0449 -1.9 12.7 Her X-1
268.4542 -1.2895 5.8 36.0 66.9 0.1226 2.0 11.1 SW J1753.5-0127
288.7745 10.8340 5.3 41.2 29.5 0.1155 2.2 6.8 GRS 1915+105
299.7528 35.1221 11.1 42.4 -10.3 -0.0403 -1.0 9.3 Cyg X-1
307.9882 40.9332 5.9 48.2 -19.5 0.0956 1.9 5.7 Cyg X-3
202.6865 24.3084 2.1 41.7 -165.3 0.2005 5.6 ------ UNKNOWN
317.3350 30.8327 1.9 57.7 -9.1 0.7994 6.0 ------ UNKNOWN
193.3322 37.5615 2.7 46.6 -144.1 0.2317 4.3 ------ UNKNOWN
319.2811 46.9144 2.3 55.5 -28.3 0.5200 5.0 ------ UNKNOWN
195.6775 53.3195 2.1 45.2 -122.1 0.5540 5.6 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-7.040000 62.440000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.6505 35.2972 1776.7 7.1 -42.2 -0.0021 -0.0 9.8 Her X-1
268.3024 -1.5007 32.6 36.1 67.3 0.3204 0.4 4.9 SW J1753.5-0127
288.7356 10.8183 11.1 41.2 29.6 -0.7991 -1.0 8.5 GRS 1915+105
299.7636 35.1549 14.2 42.4 -10.3 0.4426 0.8 8.9 Cyg X-1
308.0131 40.9610 4.6 48.2 -19.5 -1.7246 -2.5 4.4 Cyg X-3
209.8808 2.5001 2.3 46.3 162.2 4.8224 5.1 ------ UNKNOWN
314.8740 24.5758 2.6 57.7 -1.2 9.5361 4.5 ------ UNKNOWN
224.4081 28.1905 1.4 21.9 -167.1 2.8991 8.2 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
119.100590 603.050000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.4511 35.3801 6.2 26.4 13.0 0.3531 1.9 2.3 Her X-1
209.2014 4.0736 2.4 28.1 160.1 1.0396 4.8 ------ UNKNOWN
183.7669 -4.9342 2.5 51.3 -177.3 2.1944 4.7 ------ UNKNOWN
167.1730 4.2496 3.8 59.3 -156.3 4.1489 3.3 ------ UNKNOWN
167.0527 4.1923 4.1 59.4 -156.3 4.5403 3.5 ------ UNKNOWN
Plot creation:
Sat May 30 16:24:58 EDT 2015