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 -18.320 sec. to 65.712 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.26796 ( -0.25761 0.235494 )
Norm@50keV : 8.65069E-04 ( -0.000154536 0.000151016 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 48.74 using 59 bins.
Reduced chi-squared = 0.855088
# Null hypothesis probability of 7.74e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 84.03 sec: 0.148546 ( -0.016927 0.016928 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.90867e-07 ( -9.99117e-08 1.03506e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -18.320 sec. to 65.712 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.86787 ( -0.141548 1.05511 )
Epeak [keV] : 12.7057 ( -12.0102 34.651 )
Norm@50keV : 1.51514E-03 ( -0.000511266 0.00519152 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 48.16 using 59 bins.
Reduced chi-squared = 0.86
# Null hypothesis probability of 7.63e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 84.03 sec: 0.148346 ( -0.016755 0.017212 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.61096e-07 ( -1.10828e-07 1.15964e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 17.864 sec. to 18.864 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.65442 ( -0.648794 0.592877 )
Norm@50keV : 3.39196E-03 ( -0.00129424 0.00122175 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 43.57 using 59 bins.
Reduced chi-squared = 0.764386
# Null hypothesis probability of 9.05e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 0.443572 ( -0.146045 0.146188 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.1537e-08 ( -1.20798e-08 1.27575e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 17.864 sec. to 18.864 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.60175 ( -0.982396 2.65643 )
Epeak [keV] : 315.136 ( -276.653 -276.653 )
Norm@50keV : 3.62663E-03 ( -0.00372858 0.233527 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 43.56 using 59 bins.
Reduced chi-squared = 0.777857
# Null hypothesis probability of 8.87e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 0.441298 ( -0.148682 0.145739 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.10857e-08 ( -1.35275e-08 1.30897e-08 ) ergs/cm2
Time-resolved spectra
