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 -30.160 sec. to 433.944 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.79645 ( -0.138793 0.135584 )
Norm@50keV : 6.89691E-04 ( -5.53153e-05 5.45356e-05 )
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#Fit statistic : Chi-Squared = 50.27 using 59 PHA bins.
# Reduced chi-squared = 0.8820 for 57 degrees of freedom
# Null hypothesis probability = 7.235761e-01
Photon flux (15-150 keV) in 464.1 sec: 9.49123E-02 ( -0.0068828 0.0068957 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.94762e-06 ( -2.4035e-07 2.42827e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -30.160 sec. to 433.944 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.7981 ( -0.137184 0.310727 )
Epeak [keV] : 9999.34 ( -9999.35 -9999.36 )
Norm@50keV : 6.90013E-04 ( -0.000356303 0.000400575 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.28 using 59 PHA bins.
# Reduced chi-squared = 0.8978 for 56 degrees of freedom
# Null hypothesis probability = 6.902938e-01
Photon flux (15-150 keV) in 464.1 sec: 9.52219E-02 ( -0.0079567 0.0072201 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.97839e-06 ( -2.79274e-07 2.0802e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 9.324 sec. to 10.324 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.81896 ( -0.157302 0.152411 )
Norm@50keV : 1.83577E-02 ( -0.00184075 0.00181407 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 63.32 using 59 PHA bins.
# Reduced chi-squared = 1.111 for 57 degrees of freedom
# Null hypothesis probability = 2.633432e-01
Photon flux (15-150 keV) in 1 sec: 2.54862 ( -0.22784 0.22799 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.68931e-07 ( -1.70232e-08 1.72134e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 9.324 sec. to 10.324 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.33128 ( -0.57381 0.726848 )
Epeak [keV] : 61.8858 ( -17.2133 -61.8858 )
Norm@50keV : 3.40798E-02 ( -0.0165997 0.0513672 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.49 using 59 PHA bins.
# Reduced chi-squared = 1.098 for 56 degrees of freedom
# Null hypothesis probability = 2.860653e-01
Photon flux (15-150 keV) in 1 sec: 2.50680 ( -0.23502 0.23406 ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Time-resolved spectra
