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 -0.068 sec. to 0.328 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -0.889202 ( -0.101956 0.103162 )
Norm@50keV : 5.23686E-02 ( -0.00299319 0.00298501 )
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#Fit statistic : Chi-Squared = 73.71 using 59 PHA bins.
# Reduced chi-squared = 1.293 for 57 degrees of freedom
# Null hypothesis probability = 6.745055e-02
Photon flux (15-150 keV) in 0.396 sec: 0.348156 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 2.33741e-07 ( -1.49673e-08 1.50503e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.068 sec. to 0.328 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.724474 ( -0.211146 0.427077 )
Epeak [keV] : 446.613 ( -446.622 -446.622 )
Norm@50keV : 6.19740E-02 ( -0.0119018 0.0326322 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 73.21 using 59 PHA bins.
# Reduced chi-squared = 1.307 for 56 degrees of freedom
# Null hypothesis probability = 6.105317e-02
Photon flux (15-150 keV) in 0.396 sec: 5.96930 ( -0.35718 0.35611 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.3163e-07 ( -1.6037e-08 1.54427e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.368 sec. to 0.632 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.922313 ( -0.11804 0.120325 )
Norm@50keV : 2.23604E-02 ( -0.00147295 0.00146815 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 80.54 using 59 PHA bins.
# Reduced chi-squared = 1.413 for 57 degrees of freedom
# Null hypothesis probability = 2.175967e-02
Photon flux (15-150 keV) in 1 sec: 2.56723 ( -0.16997 0.17025 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.48828e-07 ( -1.76694e-08 1.77658e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.368 sec. to 0.632 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.735541 ( -0.241188 0.486472 )
Epeak [keV] : 391.375 ( -391.396 -391.396 )
Norm@50keV : 2.70216E-02 ( -0.00581058 0.0164712 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 80.03 using 59 PHA bins.
# Reduced chi-squared = 1.429 for 56 degrees of freedom
# Null hypothesis probability = 1.923312e-02
Photon flux (15-150 keV) in 1 sec: 2.54430 ( -0.17826 0.17824 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.46122e-07 ( -1.91042e-08 1.85207e-08 ) ergs/cm2
Time-resolved spectra
