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 -52.472 sec. to 5.624 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.69573 ( -0.0585692 0.0582495 )
Norm@50keV : 3.39866E-02 ( -0.00112442 0.00112323 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 80.39 using 59 PHA bins.
# Reduced chi-squared = 1.410 for 57 degrees of freedom
# Null hypothesis probability = 2.233632e-02
Photon flux (15-150 keV) in 58.1 sec: 4.50728 ( -0.15964 0.16006 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.82914e-05 ( -6.25476e-07 6.27085e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -52.472 sec. to 5.624 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.28087 ( -0.2293 0.242533 )
Epeak [keV] : 90.9497 ( -16.1818 46.794 )
Norm@50keV : 5.38375E-02 ( -0.0118008 0.0161153 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 70.44 using 59 PHA bins.
# Reduced chi-squared = 1.258 for 56 degrees of freedom
# Null hypothesis probability = 9.277030e-02
Photon flux (15-150 keV) in 58.1 sec: 4.39086 ( -0.17036 0.17094 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.78421e-05 ( -6.77405e-07 6.75558e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.212 sec. to 0.788 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.36135 ( -0.119852 0.118825 )
Norm@50keV : 0.170303 ( -0.0141603 0.0141507 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.19 using 59 PHA bins.
# Reduced chi-squared = 0.8980 for 57 degrees of freedom
# Null hypothesis probability = 6.919004e-01
Photon flux (15-150 keV) in 1 sec: 0.751056 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 1.65932e-06 ( -1.48266e-07 1.48728e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.212 sec. to 0.788 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.342177 ( -0.521315 0.587335 )
Epeak [keV] : 88.1182 ( -15.4914 36.9655 )
Norm@50keV : 0.534778 ( -0.231675 0.471308 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 39.03 using 59 PHA bins.
# Reduced chi-squared = 0.6970 for 56 degrees of freedom
# Null hypothesis probability = 9.587753e-01
Photon flux (15-150 keV) in 1 sec: 9.19469 ( -2.55237 1.65981 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.31364e-07 ( -1.71499e-07 1.57187e-07 ) ergs/cm2
Time-resolved spectra
