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 -39.776 sec. to 238.040 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.75008 ( -0.0443668 0.0442472 )
Norm@50keV : 6.66897E-03 ( -0.000145416 0.000145332 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 40.56 using 59 PHA bins.
# Reduced chi-squared = 0.7115 for 57 degrees of freedom
# Null hypothesis probability = 9.510564e-01
Photon flux (15-150 keV) in 277.8 sec: 0.901824 ( -0.022981 0.0231 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.70975e-05 ( -3.80328e-07 3.80542e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -39.776 sec. to 238.040 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.64927 ( -0.127864 0.177514 )
Epeak [keV] : 186.252 ( -111.158 -186.252 )
Norm@50keV : 7.42494E-03 ( -0.000859264 0.00150103 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 39.56 using 59 PHA bins.
# Reduced chi-squared = 0.7065 for 56 degrees of freedom
# Null hypothesis probability = 9.528741e-01
Photon flux (15-150 keV) in 277.8 sec: 0.892935 ( -0.027148 0.02734 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.69521e-05 ( -4.51736e-07 4.4246e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 157.536 sec. to 158.536 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.60565 ( -0.0945291 0.0930581 )
Norm@50keV : 5.21887E-02 ( -0.00286774 0.00285286 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.23 using 59 PHA bins.
# Reduced chi-squared = 0.9865 for 57 degrees of freedom
# Null hypothesis probability = 5.039996e-01
Photon flux (15-150 keV) in 1 sec: 6.71850 ( -0.35628 0.35662 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.87809e-07 ( -2.88541e-08 2.90356e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 157.536 sec. to 158.536 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.27212 ( -0.341828 0.370188 )
Epeak [keV] : 111.075 ( -34.4655 4377.18 )
Norm@50keV : 7.64873E-02 ( -0.0236904 0.0390779 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.44 using 59 PHA bins.
# Reduced chi-squared = 0.9543 for 56 degrees of freedom
# Null hypothesis probability = 5.722488e-01
Photon flux (15-150 keV) in 1 sec: 6.60575 ( -0.3734 0.37367 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.77035e-07 ( -3.10811e-08 3.1101e-08 ) ergs/cm2
Time-resolved spectra
