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 0.040 sec. to 1.128 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.794886 ( -0.232794 0.250689 )
Norm@50keV : 1.10396E-02 ( -0.00162854 0.00158856 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.30 using 59 PHA bins.
# Reduced chi-squared = 0.8825 for 57 degrees of freedom
# Null hypothesis probability = 7.226038e-01
Photon flux (15-150 keV) in 1.088 sec: 1.26903 ( -0.17908 0.18028 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.40678e-07 ( -1.90713e-08 1.91077e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.040 sec. to 1.128 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.627066 ( -0.62321 1.03689 )
Epeak [keV] : 500.017 ( -500.159 -500.159 )
Norm@50keV : 1.29932E-02 ( -0.00309094 0.0207791 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.20 using 59 PHA bins.
# Reduced chi-squared = 0.8964 for 56 degrees of freedom
# Null hypothesis probability = 6.930456e-01
Photon flux (15-150 keV) in 1.088 sec: 1.26279 ( -0.1813 0.18312 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.40058e-07 ( -1.96659e-08 1.89461e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.040 sec. to 1.040 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.738146 ( -0.249928 0.272623 )
Norm@50keV : 1.06965E-02 ( -0.00172456 0.00167041 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.12 using 59 PHA bins.
# Reduced chi-squared = 0.8617 for 57 degrees of freedom
# Null hypothesis probability = 7.617646e-01
Photon flux (15-150 keV) in 1 sec: 1.23308 ( -0.18548 0.18688 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.28381e-07 ( -1.83411e-08 1.83696e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.040 sec. to 1.040 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.641058 ( -0.327114 1.09151 )
Epeak [keV] : 870.906 ( -880.934 -880.934 )
Norm@50keV : 1.17329E-02 ( -0.00219293 0.0196185 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.09 using 59 PHA bins.
# Reduced chi-squared = 0.8766 for 56 degrees of freedom
# Null hypothesis probability = 7.318158e-01
Photon flux (15-150 keV) in 1 sec: 1.22980 ( -0.18743 0.18785 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.28118e-07 ( -1.87249e-08 1.85279e-08 ) ergs/cm2
Time-resolved spectra
