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 -0.024 sec. to 0.296 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.89057 ( -0.340045 0.30734 )
Norm@50keV : 1.02394E-02 ( -0.00247323 0.00241023 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 66.51 using 59 PHA bins.
# Reduced chi-squared = 1.167 for 57 degrees of freedom
# Null hypothesis probability = 1.822481e-01
Photon flux (15-150 keV) in 0.32 sec: 1.46372 ( -0.2918 0.2918 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.01217e-08 ( -7.02131e-09 7.23251e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.024 sec. to 0.296 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.488963 ( -1.68099 2.74508 )
Epeak [keV] : 44.5679 ( -8.91917 16.0558 )
Norm@50keV : 0.230707 ( -0.231081 9.09999 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.78 using 59 PHA bins.
# Reduced chi-squared = 1.068 for 56 degrees of freedom
# Null hypothesis probability = 3.400246e-01
Photon flux (15-150 keV) in 0.32 sec: 1.41223 ( -0.28997 0.29155 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.6809e-08 ( -6.2945e-09 7.152e-09 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.332 sec. to 0.668 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.81491 ( -0.561778 0.482947 )
Norm@50keV : 3.61151E-03 ( -0.00132002 0.00125856 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 67.41 using 59 PHA bins.
# Reduced chi-squared = 1.183 for 57 degrees of freedom
# Null hypothesis probability = 1.627446e-01
Photon flux (15-150 keV) in 1 sec: 0.500589 ( -0.149475 0.14948 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.32392e-08 ( -1.1696e-08 1.23183e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.332 sec. to 0.668 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.259868 ( )
Epeak [keV] : 48.0544 ( )
Norm@50keV : 4.98508E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 65.42 using 59 PHA bins.
# Reduced chi-squared = 1.168 for 56 degrees of freedom
# Null hypothesis probability = 1.822262e-01
Photon flux (15-150 keV) in 1 sec: 0.474376 ( -0.155996 0.153354 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.94517e-08 ( -1.02071e-08 1.26549e-08 ) ergs/cm2
Time-resolved spectra
