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 -13.476 sec. to 246.584 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.47483 ( -0.10893 0.108997 )
Norm@50keV : 1.71593E-03 ( -0.000111048 0.000110934 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 54.86 using 59 bins.
Reduced chi-squared = 0.962456
# Null hypothesis probability of 5.56e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 260.1 sec: 0.212803 ( -0.01424 0.014269 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.25245e-06 ( -2.95687e-07 2.97326e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -13.476 sec. to 246.584 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.815625 ( -0.453595 0.507698 )
Epeak [keV] : 91.5890 ( -20.3305 85.175 )
Norm@50keV : 3.64610E-03 ( -0.00144818 0.00276123 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 48.42 using 59 bins.
Reduced chi-squared = 0.864643
# Null hypothesis probability of 7.54e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 260.1 sec: 0.206685 ( -0.014865 0.014868 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.0695e-06 ( -3.2339e-07 3.23897e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.092 sec. to 1.092 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.13133 ( -0.350513 0.378532 )
Norm@50keV : 9.18302E-03 ( -0.00193783 0.00191446 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 43.94 using 59 bins.
Reduced chi-squared = 0.770877
# Null hypothesis probability of 8.98e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 1.06864 ( -0.23561 0.23714 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.50824e-08 ( -2.02861e-08 2.0332e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.092 sec. to 1.092 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.37968 ( -4.98502 2.31095 )
Epeak [keV] : 124.514 ( )
Norm@50keV : 1.21184E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared 43.42 using 59 bins.
Reduced chi-squared = 0.775357
# Null hypothesis probability of 8.90e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 1.07026 ( -0.239977 0.23811 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.53059e-08 ( -2.14339e-08 1.96761e-08 ) ergs/cm2
Time-resolved spectra
