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 -13.340 sec. to 120.876 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.89466 ( -0.098943 0.0972653 )
Norm@50keV : 2.33505E-03 ( -0.000137942 0.000136656 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.79 using 59 PHA bins.
# Reduced chi-squared = 1.101 for 57 degrees of freedom
# Null hypothesis probability = 2.787747e-01
Photon flux (15-150 keV) in 134.2 sec: 0.334367 ( -0.017499 0.017522 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.88133e-06 ( -1.67686e-07 1.69183e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -13.340 sec. to 120.876 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.53835 ( -0.384902 0.431425 )
Epeak [keV] : 56.8548 ( -13.493 -56.8561 )
Norm@50keV : 3.67632E-03 ( -0.00138019 0.00265054 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.32 using 59 PHA bins.
# Reduced chi-squared = 1.077 for 56 degrees of freedom
# Null hypothesis probability = 3.226030e-01
Photon flux (15-150 keV) in 134.2 sec: 0.327826 ( -0.018861 0.018845 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.76887e-06 ( -2.05432e-07 2.06581e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 75.440 sec. to 76.440 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.48231 ( -0.166806 0.16454 )
Norm@50keV : 1.01829E-02 ( -0.00102455 0.00101937 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.81 using 59 PHA bins.
# Reduced chi-squared = 1.102 for 57 degrees of freedom
# Null hypothesis probability = 2.779305e-01
Photon flux (15-150 keV) in 1 sec: 1.26531 ( -0.12533 0.12548 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.68969e-08 ( -1.06586e-08 1.0762e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 75.440 sec. to 76.440 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.651006 ( -0.704842 0.836626 )
Epeak [keV] : 80.8231 ( -19.8093 150.858 )
Norm@50keV : 2.68040E-02 ( -0.0147666 0.0426238 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.67 using 59 PHA bins.
# Reduced chi-squared = 1.048 for 56 degrees of freedom
# Null hypothesis probability = 3.777509e-01
Photon flux (15-150 keV) in 1 sec: 1.22175 ( -0.13103 0.1308 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.1283e-08 ( -6.31801e-09 1.18078e-08 ) ergs/cm2
Time-resolved spectra
