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 -4.616 sec. to 16.048 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.37998 ( -0.104744 0.104414 )
Norm@50keV : 3.58225E-03 ( -0.000234279 0.000233843 )
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#Fit statistic : Chi-Squared = 60.98 using 59 PHA bins.
# Reduced chi-squared = 1.070 for 57 degrees of freedom
# Null hypothesis probability = 3.347040e-01
Photon flux (15-150 keV) in 20.66 sec: 0.434319 ( -0.028173 0.02819 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.18191e-07 ( -5.21359e-08 5.25708e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -4.616 sec. to 16.048 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.112799 ( -0.493662 0.557472 )
Epeak [keV] : 74.3006 ( -9.72074 17.4363 )
Norm@50keV : 1.55456E-02 ( -0.00662526 0.0134564 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 38.22 using 59 PHA bins.
# Reduced chi-squared = 0.6826 for 56 degrees of freedom
# Null hypothesis probability = 9.667508e-01
Photon flux (15-150 keV) in 20.66 sec: 0.413572 ( -0.029231 0.029235 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.56509e-07 ( -5.55975e-08 5.67224e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.912 sec. to 1.912 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.28913 ( -0.16438 0.163871 )
Norm@50keV : 1.18593E-02 ( -0.00120866 0.00120562 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.02 using 59 PHA bins.
# Reduced chi-squared = 1.053 for 57 degrees of freedom
# Null hypothesis probability = 3.667624e-01
Photon flux (15-150 keV) in 1 sec: 1.41206 ( -0.14274 0.1428 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.1752e-07 ( -1.35208e-08 1.36426e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.912 sec. to 1.912 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.560834 ( -0.670704 0.802204 )
Epeak [keV] : 100.261 ( -29.6329 420.081 )
Norm@50keV : 2.76033E-02 ( -0.0146866 0.0403714 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.55 using 59 PHA bins.
# Reduced chi-squared = 1.010 for 56 degrees of freedom
# Null hypothesis probability = 4.544605e-01
Photon flux (15-150 keV) in 1 sec: 1.38187 ( -0.1465 0.14594 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.11954e-07 ( -1.46882e-08 1.47295e-08 ) ergs/cm2
Time-resolved spectra
