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 -1.764 sec. to 2.588 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.94206 ( -0.15735 0.151049 )
Norm@50keV : 6.60436E-03 ( -0.000688309 0.000677632 )
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#Fit statistic : Chi-Squared = 46.79 using 59 PHA bins.
# Reduced chi-squared = 0.8208 for 57 degrees of freedom
# Null hypothesis probability = 8.307482e-01
Photon flux (15-150 keV) in 4.352 sec: 0.965237 ( -0.08355 0.083583 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.64496e-07 ( -2.65112e-08 2.69037e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.764 sec. to 2.588 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.790421 ( -0.760297 0.932866 )
Epeak [keV] : 44.1774 ( -7.41602 12.1875 )
Norm@50keV : 3.00939E-02 ( -0.0188746 0.0738189 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 39.51 using 59 PHA bins.
# Reduced chi-squared = 0.7056 for 56 degrees of freedom
# Null hypothesis probability = 9.534661e-01
Photon flux (15-150 keV) in 4.352 sec: 0.926616 ( -0.087143 0.087184 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.38962e-07 ( -2.88367e-08 3.06682e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.256 sec. to 1.256 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.80949 ( -0.206624 0.1971 )
Norm@50keV : 1.06269E-02 ( -0.00144085 0.00141541 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.40 using 59 PHA bins.
# Reduced chi-squared = 1.007 for 57 degrees of freedom
# Null hypothesis probability = 4.601285e-01
Photon flux (15-150 keV) in 1 sec: 1.46987 ( -0.17498 0.17507 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.7816e-08 ( -1.33231e-08 1.35186e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.256 sec. to 1.256 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.197659 ( -1.16081 1.5621 )
Epeak [keV] : 48.6118 ( -7.87497 19.8587 )
Norm@50keV : 8.42748E-02 ( -0.0844755 0.550459 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.32 using 59 PHA bins.
# Reduced chi-squared = 0.9165 for 56 degrees of freedom
# Null hypothesis probability = 6.522154e-01
Photon flux (15-150 keV) in 1 sec: 1.39435 ( -0.18424 0.18383 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.63853e-08 ( -1.388e-08 1.53121e-08 ) ergs/cm2
Time-resolved spectra
