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 -1.872 sec. to 136.064 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.64213 ( -0.225703 0.219667 )
Norm@50keV : 1.30195E-03 ( -0.00017574 0.000172912 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 55.38 using 59 bins.
Reduced chi-squared = 0.971579
# Null hypothesis probability of 5.36e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 137.9 sec: 0.169570 ( -0.021272 0.021295 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.67133e-06 ( -2.38637e-07 2.42235e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.872 sec. to 136.064 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.31019 ( -0.543643 1.32404 )
Epeak [keV] : 96.8698 ( -53.7038 -97.1122 )
Norm@50keV : 1.96178E-03 ( -0.00195756 0.00801941 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 55.10 using 59 bins.
Reduced chi-squared = 0.983929
# Null hypothesis probability of 5.09e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 137.9 sec: 0.167228 ( -0.022905 0.022501 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.62045e-06 ( -2.91146e-07 2.54176e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 2.164 sec. to 3.164 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.36573 ( -0.567077 0.579828 )
Norm@50keV : 7.72720E-03 ( -0.00246918 0.00244152 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 61.74 using 59 bins.
Reduced chi-squared = 1.08316
# Null hypothesis probability of 3.11e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 0.933985 ( -0.298638 0.299815 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.5216e-08 ( -2.62201e-08 2.69038e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 2.164 sec. to 3.164 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.36267 ( 1.31628 2.4719 )
Epeak [keV] : 9999.19 ( -9999.21 -9999.21 )
Norm@50keV : 7.75668E-03 ( -0.00775668 0.174417 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 61.74 using 59 bins.
Reduced chi-squared = 1.1025
# Null hypothesis probability of 2.78e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 0.935580 ( -0.302468 0.29965 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.54362e-08 ( -2.94444e-08 2.26369e-08 ) ergs/cm2
Time-resolved spectra
