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 0.052 sec. to 0.236 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.57652 ( -0.284584 0.261337 )
Norm@50keV : 5.07332E-02 ( -0.00895201 0.0087584 )
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#Fit statistic : Chi-Squared 40.40 using 59 bins.
Reduced chi-squared = 0.708772
# Null hypothesis probability of 9.53e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 0.184 sec: 6.47313 ( -1.05376 1.0541 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.75726e-08 ( -1.654e-08 1.66754e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.052 sec. to 0.236 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.14456 ( -0.676514 1.10238 )
Epeak [keV] : 107.595 ( -49.5811 -107.59 )
Norm@50keV : 8.22471E-02 ( -0.0822497 0.194258 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 39.75 using 59 bins.
Reduced chi-squared = 0.709821
# Null hypothesis probability of 9.51e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 0.184 sec: 6.41966 ( -1.06217 1.06068 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.36189e-08 ( -1.95375e-08 1.49612e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.354 sec. to 0.646 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.31044 ( -0.422539 0.421185 )
Norm@50keV : 1.23179E-02 ( -0.00283687 0.0028283 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 49.63 using 59 bins.
Reduced chi-squared = 0.870702
# Null hypothesis probability of 7.45e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 1.47244 ( -0.34498 0.34645 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.21431e-07 ( -3.11638e-08 3.1639e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.354 sec. to 0.646 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.7129 ( -1.35011 3.06167 )
Epeak [keV] : 220.521 ( )
Norm@50keV : 1.83020E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared 48.85 using 59 bins.
Reduced chi-squared = 0.872321
# Null hypothesis probability of 7.40e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 1.47622 ( -0.36664 0.3471 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.21776e-07 ( -3.42595e-08 2.7727e-08 ) ergs/cm2
Time-resolved spectra
