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 -3.404 sec. to 32.312 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.85273 ( -0.255446 0.243409 )
Norm@50keV : 1.98432E-03 ( -0.000319047 0.000310529 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.91 using 59 PHA bins.
# Reduced chi-squared = 1.086 for 57 degrees of freedom
# Null hypothesis probability = 3.051781e-01
Photon flux (15-150 keV) in 35.72 sec: 0.279242 ( -0.0383 0.038326 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.51811e-07 ( -1.03154e-07 1.05094e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -3.404 sec. to 32.312 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.69209 ( -0.618229 0.975161 )
Epeak [keV] : 84.7415 ( -84.7204 -84.7415 )
Norm@50keV : 2.44189E-03 ( -0.00244189 0.00615125 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.80 using 59 PHA bins.
# Reduced chi-squared = 1.104 for 56 degrees of freedom
# Null hypothesis probability = 2.766341e-01
Photon flux (15-150 keV) in 35.72 sec: 0.277656 ( -0.039139 0.019684 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.41803e-07 ( -1.15408e-07 1.12371e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -1.580 sec. to -0.580 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.55388 ( -0.492169 0.465746 )
Norm@50keV : 5.96080E-03 ( -0.0017918 0.00176072 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 69.77 using 59 PHA bins.
# Reduced chi-squared = 1.224 for 57 degrees of freedom
# Null hypothesis probability = 1.193639e-01
Photon flux (15-150 keV) in 1 sec: 0.755478 ( -0.220854 0.221689 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.60919e-08 ( -1.76911e-08 1.80733e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.580 sec. to -0.580 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.24015 ( -1.66296 3.68785 )
Epeak [keV] : 69.2655 ( -23.6272 -69.2666 )
Norm@50keV : 2.63034E-02 ( -0.0263168 1.6449 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 68.52 using 59 PHA bins.
# Reduced chi-squared = 1.223 for 56 degrees of freedom
# Null hypothesis probability = 1.217200e-01
Photon flux (15-150 keV) in 1 sec: 0.720856 ( -0.231069 0.22976 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.30078e-08 ( -1.80415e-08 1.87733e-08 ) ergs/cm2
Time-resolved spectra
