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 -14.432 sec. to 62.428 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.91432 ( -0.159018 0.152891 )
Norm@50keV : 1.21458E-03 ( -0.000120747 0.000118532 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 43.10 using 59 PHA bins.
# Reduced chi-squared = 0.7562 for 57 degrees of freedom
# Null hypothesis probability = 9.133322e-01
Photon flux (15-150 keV) in 76.86 sec: 0.175385 ( -0.014082 0.014089 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.58557e-07 ( -8.25054e-08 8.40495e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -14.432 sec. to 62.428 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.48688 ( -0.588989 0.689562 )
Epeak [keV] : 52.1641 ( -40.0524 -52.1641 )
Norm@50keV : 2.10617E-03 ( -0.00109238 0.00299553 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 41.59 using 59 PHA bins.
# Reduced chi-squared = 0.7427 for 56 degrees of freedom
# Null hypothesis probability = 9.243762e-01
Photon flux (15-150 keV) in 76.86 sec: 0.171779 ( -0.014922 0.014909 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.20557e-07 ( -9.56538e-08 9.81564e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 46.628 sec. to 47.628 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.43109 ( -0.290112 0.288864 )
Norm@50keV : 5.76227E-03 ( -0.00099621 0.000986198 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.84 using 59 PHA bins.
# Reduced chi-squared = 0.9972 for 57 degrees of freedom
# Null hypothesis probability = 4.810769e-01
Photon flux (15-150 keV) in 1 sec: 0.706865 ( -0.119131 0.119243 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.53439e-08 ( -1.05571e-08 1.07361e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 46.628 sec. to 47.628 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.26533 ( )
Epeak [keV] : 214.026 ( )
Norm@50keV : 7.04881E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.77 using 59 PHA bins.
# Reduced chi-squared = 1.014 for 56 degrees of freedom
# Null hypothesis probability = 4.460756e-01
Photon flux (15-150 keV) in 1 sec: 0.702986 ( -0.12215 0.121347 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.45444e-08 ( -1.18855e-08 1.13381e-08 ) ergs/cm2
Time-resolved spectra
