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 -0.252 sec. to 20.128 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.83484 ( -0.0719284 0.071146 )
Norm@50keV : 8.17967E-03 ( -0.000338913 0.000337552 )
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#Fit statistic : Chi-Squared = 65.86 using 59 PHA bins.
# Reduced chi-squared = 1.155 for 57 degrees of freedom
# Null hypothesis probability = 1.971461e-01
Photon flux (15-150 keV) in 20.38 sec: 1.14279 ( -0.04692 0.04703 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.53343e-06 ( -6.40835e-08 6.4303e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.252 sec. to 20.128 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.1521 ( -0.299258 0.320906 )
Epeak [keV] : 60.3440 ( -6.94553 12.1691 )
Norm@50keV : 1.82095E-02 ( -0.00527913 0.00814343 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.30 using 59 PHA bins.
# Reduced chi-squared = 0.8803 for 56 degrees of freedom
# Null hypothesis probability = 7.247078e-01
Photon flux (15-150 keV) in 20.38 sec: 1.09447 ( -0.05074 0.0509 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.45363e-06 ( -7.18968e-08 7.22634e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 9.392 sec. to 10.392 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.5288 ( -0.0725307 0.072084 )
Norm@50keV : 4.50417E-02 ( -0.00206016 0.00205716 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 77.53 using 59 PHA bins.
# Reduced chi-squared = 1.360 for 57 degrees of freedom
# Null hypothesis probability = 3.658779e-02
Photon flux (15-150 keV) in 1 sec: 5.66780 ( -0.26112 0.26136 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.25412e-07 ( -2.08454e-08 2.09118e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 9.392 sec. to 10.392 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.422249 ( -0.3384 0.366726 )
Epeak [keV] : 72.1259 ( -7.29081 11.2516 )
Norm@50keV : 0.161036 ( -0.0509013 0.0822929 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 40.74 using 59 PHA bins.
# Reduced chi-squared = 0.7275 for 56 degrees of freedom
# Null hypothesis probability = 9.375225e-01
Photon flux (15-150 keV) in 1 sec: 5.44211 ( -0.26919 0.2694 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.42913e-07 ( -2.53525e-08 2.25842e-08 ) ergs/cm2
Time-resolved spectra
