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 -69.384 sec. to 121.336 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.52889 ( -0.071837 0.0716782 )
Norm@50keV : 2.84867E-03 ( -0.000109224 0.000109067 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.87 using 59 PHA bins.
# Reduced chi-squared = 0.9626 for 57 degrees of freedom
# Null hypothesis probability = 5.555126e-01
Photon flux (15-150 keV) in 190.7 sec: 0.358470 ( -0.014522 0.014576 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.13075e-06 ( -2.11587e-07 2.12323e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -69.384 sec. to 121.336 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.40526 ( -0.159753 0.282257 )
Epeak [keV] : 252.625 ( -252.618 -252.618 )
Norm@50keV : 3.26543E-03 ( -0.000504689 0.0011549 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.25 using 59 PHA bins.
# Reduced chi-squared = 0.9688 for 56 degrees of freedom
# Null hypothesis probability = 5.412890e-01
Photon flux (15-150 keV) in 190.7 sec: 0.355522 ( -0.015797 0.015786 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.08231e-06 ( -2.36561e-07 2.31069e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 1.060 sec. to 2.060 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.23367 ( -0.119777 0.120659 )
Norm@50keV : 3.82497E-02 ( -0.00258645 0.00258622 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 66.73 using 59 PHA bins.
# Reduced chi-squared = 1.171 for 57 degrees of freedom
# Null hypothesis probability = 1.772949e-01
Photon flux (15-150 keV) in 1 sec: 4.51221 ( -0.31409 0.31447 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.84512e-07 ( -2.90035e-08 2.91923e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.060 sec. to 2.060 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.17551 ( -0.16768 0.474647 )
Epeak [keV] : 752.779 ( -753.484 -753.484 )
Norm@50keV : 4.08123E-02 ( -0.00480845 0.0274934 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 66.68 using 59 PHA bins.
# Reduced chi-squared = 1.191 for 56 degrees of freedom
# Null hypothesis probability = 1.554199e-01
Photon flux (15-150 keV) in 1 sec: 4.50127 ( -0.32458 0.31715 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.82992e-07 ( -3.14882e-08 2.90581e-08 ) ergs/cm2
Time-resolved spectra
