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 -3.408 sec. to 30.064 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.48168 ( -0.138809 0.138371 )
Norm@50keV : 6.93346E-03 ( -0.000551449 0.000550851 )
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#Fit statistic : Chi-Squared = 53.04 using 59 PHA bins.
# Reduced chi-squared = 0.9305 for 57 degrees of freedom
# Null hypothesis probability = 6.243914e-01
Photon flux (15-150 keV) in 33.47 sec: 0.861390 ( -0.072636 0.072879 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.20849e-06 ( -1.86656e-07 1.87503e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -3.408 sec. to 30.064 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.24892 ( -0.306486 0.57413 )
Epeak [keV] : 175.560 ( -175.56 -175.56 )
Norm@50keV : 8.93286E-03 ( -0.002463 0.00742332 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.46 using 59 PHA bins.
# Reduced chi-squared = 0.9368 for 56 degrees of freedom
# Null hypothesis probability = 6.095882e-01
Photon flux (15-150 keV) in 33.47 sec: 0.851877 ( -0.075574 0.075752 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.18522e-06 ( -1.95669e-07 1.9477e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.028 sec. to 1.028 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.2934 ( -0.248764 0.253933 )
Norm@50keV : 2.23271E-02 ( -0.00342025 0.00341355 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.71 using 59 PHA bins.
# Reduced chi-squared = 0.9072 for 57 degrees of freedom
# Null hypothesis probability = 6.731106e-01
Photon flux (15-150 keV) in 1 sec: 2.66051 ( -0.43108 0.43388 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.21014e-07 ( -3.53661e-08 3.55053e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.028 sec. to 1.028 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.457112 ( -0.94586 1.48887 )
Epeak [keV] : 99.7549 ( -31.91 -99.7245 )
Norm@50keV : 5.56602E-02 ( -0.0354087 0.215013 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.10 using 59 PHA bins.
# Reduced chi-squared = 0.8946 for 56 degrees of freedom
# Null hypothesis probability = 6.967713e-01
Photon flux (15-150 keV) in 1 sec: 2.58656 ( -0.44192 0.44456 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.12917e-07 ( -3.91129e-08 3.79249e-08 ) ergs/cm2
Time-resolved spectra
