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 -1.344 sec. to 1.828 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.84845 ( -0.225326 0.212989 )
Norm@50keV : 5.97874E-03 ( -0.000889968 0.000869387 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.84 using 59 PHA bins.
# Reduced chi-squared = 0.9971 for 57 degrees of freedom
# Null hypothesis probability = 4.812263e-01
Photon flux (15-150 keV) in 3.172 sec: 0.839892 ( -0.104718 0.104742 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.74407e-07 ( -2.56512e-08 2.61297e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.344 sec. to 1.828 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.00238 ( -0.912072 1.13633 )
Epeak [keV] : 51.3105 ( -14.2445 -51.3105 )
Norm@50keV : 1.79401E-02 ( -0.0179401 0.0608771 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.39 using 59 PHA bins.
# Reduced chi-squared = 0.9712 for 56 degrees of freedom
# Null hypothesis probability = 5.361500e-01
Photon flux (15-150 keV) in 3.172 sec: 0.819013 ( -0.107099 0.107156 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.62485e-07 ( -2.72457e-08 2.8867e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.024 sec. to 0.976 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.97547 ( -0.267695 0.247858 )
Norm@50keV : 7.91713E-03 ( -0.00155086 0.00151982 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 68.93 using 59 PHA bins.
# Reduced chi-squared = 1.209 for 57 degrees of freedom
# Null hypothesis probability = 1.336120e-01
Photon flux (15-150 keV) in 1 sec: 1.17446 ( -0.185841 0.18585 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.2929e-08 ( -1.35094e-08 1.38391e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.024 sec. to 0.976 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.826273 ( -1.59634 2.32607 )
Epeak [keV] : 39.6142 ( -5.87684 8.09673 )
Norm@50keV : 0.375409 ( -0.388101 10.1983 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.88 using 59 PHA bins.
# Reduced chi-squared = 1.034 for 56 degrees of freedom
# Null hypothesis probability = 4.057696e-01
Photon flux (15-150 keV) in 1 sec: 1.13600 ( -0.182935 0.18398 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.25331e-08 ( -1.16176e-08 1.29448e-08 ) ergs/cm2
Time-resolved spectra
