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 -0.252 sec. to 31.072 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.55061 ( -0.0787472 0.0772689 )
Norm@50keV : 5.04302E-03 ( -0.000235621 0.000234254 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 84.01 using 59 PHA bins.
# Reduced chi-squared = 1.474 for 57 degrees of freedom
# Null hypothesis probability = 1.147416e-02
Photon flux (15-150 keV) in 31.32 sec: 1.02237 ( -0.038851 0.03908 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.60229e-06 ( -5.64634e-08 5.66122e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.252 sec. to 31.072 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.37548 ( -0.40654 0.448084 )
Epeak [keV] : 21.0352 ( -9.98031 5.44973 )
Norm@50keV : 2.40307E-02 ( -0.00997434 0.0197388 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.84 using 59 PHA bins.
# Reduced chi-squared = 0.9793 for 56 degrees of freedom
# Null hypothesis probability = 5.188601e-01
Photon flux (15-150 keV) in 31.32 sec: 0.996266 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 1.43219e-06 ( -7.08386e-08 7.32393e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 13.104 sec. to 14.104 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.60093 ( -0.178374 0.168388 )
Norm@50keV : 1.04540E-02 ( -0.00132476 0.00131844 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.90 using 59 PHA bins.
# Reduced chi-squared = 0.9806 for 57 degrees of freedom
# Null hypothesis probability = 5.165443e-01
Photon flux (15-150 keV) in 1 sec: 2.18786 ( -0.16919 0.16927 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.07664e-07 ( -9.58636e-09 9.77707e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 13.104 sec. to 14.104 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.643 ( -0.350882 1.12976 )
Epeak [keV] : 12.8240 ( )
Norm@50keV : 4.31391E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.09 using 59 PHA bins.
# Reduced chi-squared = 0.9302 for 56 degrees of freedom
# Null hypothesis probability = 6.235253e-01
Photon flux (15-150 keV) in 1 sec: 2.11585 ( -0.17907 0.17831 ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Time-resolved spectra
