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 -0.092 sec. to 2.576 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.35044 ( -0.0838034 0.0838171 )
Norm@50keV : 4.82799E-02 ( -0.00237783 0.0023776 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.43 using 59 PHA bins.
# Reduced chi-squared = 0.9900 for 57 degrees of freedom
# Null hypothesis probability = 4.963793e-01
Photon flux (15-150 keV) in 2.668 sec: 5.81694 ( -0.30015 0.30056 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.2581e-06 ( -6.69249e-08 6.70821e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.092 sec. to 2.576 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.04767 ( -0.322737 0.341034 )
Epeak [keV] : 174.070 ( -64.1602 -174.07 )
Norm@50keV : 6.68534E-02 ( -0.0188982 0.0284271 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.78 using 59 PHA bins.
# Reduced chi-squared = 0.9604 for 56 degrees of freedom
# Null hypothesis probability = 5.593723e-01
Photon flux (15-150 keV) in 2.668 sec: 5.74688 ( -0.30874 0.30901 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.24307e-06 ( -6.95646e-08 6.93571e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.092 sec. to 0.908 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.48139 ( -0.104241 0.103489 )
Norm@50keV : 6.28050E-02 ( -0.00414283 0.00413688 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 76.07 using 59 PHA bins.
# Reduced chi-squared = 1.335 for 57 degrees of freedom
# Null hypothesis probability = 4.651691e-02
Photon flux (15-150 keV) in 1 sec: 7.80215 ( -0.52434 0.52482 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.97737e-07 ( -4.22678e-08 4.24104e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.092 sec. to 0.908 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.806976 ( -0.428726 0.469556 )
Epeak [keV] : 93.6656 ( -19.2499 68.5451 )
Norm@50keV : 0.134295 ( -0.050397 0.089033 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 68.53 using 59 PHA bins.
# Reduced chi-squared = 1.224 for 56 degrees of freedom
# Null hypothesis probability = 1.214079e-01
Photon flux (15-150 keV) in 1 sec: 7.66691 ( -0.53231 0.53245 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.42492e-07 ( -4.90042e-08 4.23035e-08 ) ergs/cm2
Time-resolved spectra
