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 14.008 sec. to 73.448 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.72964 ( -0.278934 0.266247 )
Norm@50keV : 8.55671E-04 ( -0.000151343 0.000147524 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 45.06 using 59 PHA bins.
# Reduced chi-squared = 0.7906 for 57 degrees of freedom
# Null hypothesis probability = 8.736079e-01
Photon flux (15-150 keV) in 59.44 sec: 0.114850 ( -0.0175486 0.017555 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.69968e-07 ( -8.50586e-08 8.72544e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 14.008 sec. to 73.448 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.16507 ( -1.06698 1.50347 )
Epeak [keV] : 64.1194 ( -24.5591 -64.1112 )
Norm@50keV : 1.78513E-03 ( -0.0017856 0.0109461 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.38 using 59 PHA bins.
# Reduced chi-squared = 0.7925 for 56 degrees of freedom
# Null hypothesis probability = 8.687236e-01
Photon flux (15-150 keV) in 59.44 sec: 0.112472 ( -0.0183026 0.018224 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.41976e-07 ( -9.75559e-08 1.03278e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 17.676 sec. to 18.676 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.29508 ( -1.36373 0.849725 )
Norm@50keV : 1.82461E-03 ( -0.00182457 0.0012245 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.69 using 59 PHA bins.
# Reduced chi-squared = 1.012 for 57 degrees of freedom
# Null hypothesis probability = 4.493780e-01
Photon flux (15-150 keV) in 1 sec: 0.318039 ( -0.131799 0.13186 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.74241e-08 ( -9.34003e-09 1.06748e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 17.676 sec. to 18.676 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.55653 ( -0.253567 3.76707 )
Epeak [keV] : 205.648 ( )
Norm@50keV : 1.32121E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.65 using 59 PHA bins.
# Reduced chi-squared = 1.029 for 56 degrees of freedom
# Null hypothesis probability = 4.140643e-01
Photon flux (15-150 keV) in 1 sec: 0.315886 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Time-resolved spectra