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 -0.532 sec. to 319.800 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.17677 ( -0.180775 0.171632 )
Norm@50keV : 6.70337E-04 ( -7.79085e-05 7.62261e-05 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.25 using 59 PHA bins.
# Reduced chi-squared = 0.9342 for 57 degrees of freedom
# Null hypothesis probability = 6.165036e-01
Photon flux (15-150 keV) in 320.3 sec: 0.109649 ( -0.009081 0.009089 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.01278e-06 ( -1.9937e-07 2.03763e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.532 sec. to 319.800 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.21123 ( 1.99383 0.576839 )
Epeak [keV] : 258.943 ( )
Norm@50keV : 6.40787E-04 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.29 using 59 PHA bins.
# Reduced chi-squared = 0.9516 for 56 degrees of freedom
# Null hypothesis probability = 5.782096e-01
Photon flux (15-150 keV) in 320.3 sec: 0.109364 ( -0.009064 0.009866 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.00871e-06 ( -1.97004e-07 2.22125e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.272 sec. to 0.728 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.54388 ( -0.135831 0.134137 )
Norm@50keV : 2.24149E-02 ( -0.00183708 0.0018264 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.80 using 59 PHA bins.
# Reduced chi-squared = 1.032 for 57 degrees of freedom
# Null hypothesis probability = 4.092957e-01
Photon flux (15-150 keV) in 1 sec: 2.83267 ( -0.2263 0.22649 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.11232e-07 ( -1.87412e-08 1.88963e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.272 sec. to 0.728 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.2582 ( -0.356223 0.523176 )
Epeak [keV] : 129.068 ( )
Norm@50keV : 3.14208E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.74 using 59 PHA bins.
# Reduced chi-squared = 1.031 for 56 degrees of freedom
# Null hypothesis probability = 4.106203e-01
Photon flux (15-150 keV) in 1 sec: 2.80362 ( -0.23 0.23138 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.07195e-07 ( -2.01225e-08 2.00582e-08 ) ergs/cm2
Time-resolved spectra
