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 -18.496 sec. to 200.720 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.23408 ( -0.0723124 0.0726564 )
Norm@50keV : 1.96688E-03 ( -7.746e-05 7.74547e-05 )
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#Fit statistic : Chi-Squared = 56.42 using 59 PHA bins.
# Reduced chi-squared = 0.9898 for 57 degrees of freedom
# Null hypothesis probability = 4.967663e-01
Photon flux (15-150 keV) in 219.2 sec: 0.232042 ( -0.009594 0.009611 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.33363e-06 ( -1.87043e-07 1.87747e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -18.496 sec. to 200.720 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -0.838804 ( -0.290594 0.311595 )
Epeak [keV] : 162.081 ( -48.0137 267.65 )
Norm@50keV : 2.98271E-03 ( -0.000768864 0.0011179 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.90 using 59 PHA bins.
# Reduced chi-squared = 0.9090 for 56 degrees of freedom
# Null hypothesis probability = 6.676338e-01
Photon flux (15-150 keV) in 219.2 sec: 0.226666 ( -0.010324 0.010334 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.21892e-06 ( -2.07109e-07 2.06256e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 123.632 sec. to 124.632 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.64014 ( -0.262587 0.251072 )
Norm@50keV : 7.02225E-03 ( -0.00123796 0.00121348 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.12 using 59 PHA bins.
# Reduced chi-squared = 0.9669 for 57 degrees of freedom
# Null hypothesis probability = 5.460780e-01
Photon flux (15-150 keV) in 1 sec: 0.914007 ( -0.142269 0.142273 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.53853e-08 ( -1.2107e-08 1.23987e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 123.632 sec. to 124.632 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.244553 ( -1.35247 2.42407 )
Epeak [keV] : 52.3329 ( -13.0308 214.273 )
Norm@50keV : 4.53022E-02 ( -0.0454989 1.29303 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.02 using 59 PHA bins.
# Reduced chi-squared = 0.9289 for 56 degrees of freedom
# Null hypothesis probability = 6.263991e-01
Photon flux (15-150 keV) in 1 sec: 0.877201 ( -0.150425 0.148479 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.63547e-08 ( -1.39982e-08 1.53141e-08 ) ergs/cm2
Time-resolved spectra
