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 -197.320 sec. to 119.072 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.39799 ( -0.0368498 0.0369264 )
Norm@50keV : 5.80646E-03 ( -0.000113539 0.0001135 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.42 using 59 PHA bins.
# Reduced chi-squared = 0.9372 for 57 degrees of freedom
# Null hypothesis probability = 6.101241e-01
Photon flux (15-150 keV) in 316.4 sec: 0.706808 ( -0.015701 0.015753 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.77614e-05 ( -3.55067e-07 3.55222e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -197.320 sec. to 119.072 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.04668 ( -0.154688 0.160069 )
Epeak [keV] : 156.263 ( -31.216 74.7154 )
Norm@50keV : 8.25609E-03 ( -0.00115828 0.00139512 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 37.85 using 59 PHA bins.
# Reduced chi-squared = 0.6758 for 56 degrees of freedom
# Null hypothesis probability = 9.700394e-01
Photon flux (15-150 keV) in 316.4 sec: 0.687464 ( -0.017508 0.0176 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.73935e-05 ( -3.91235e-07 3.9039e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -177.488 sec. to -176.488 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.06726 ( -0.0633837 0.0637116 )
Norm@50keV : 8.08216E-02 ( -0.00296425 0.00296293 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.19 using 59 PHA bins.
# Reduced chi-squared = 0.8981 for 57 degrees of freedom
# Null hypothesis probability = 6.917653e-01
Photon flux (15-150 keV) in 1 sec: 9.34728 ( -0.3513 0.35155 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.54142e-07 ( -3.43192e-08 3.44042e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -177.488 sec. to -176.488 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.76358 ( -0.247161 0.26185 )
Epeak [keV] : 233.004 ( -81.6318 653.852 )
Norm@50keV : 0.110688 ( -0.0244401 0.0332767 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 46.73 using 59 PHA bins.
# Reduced chi-squared = 0.8345 for 56 degrees of freedom
# Null hypothesis probability = 8.065745e-01
Photon flux (15-150 keV) in 1 sec: 9.23907 ( -0.36141 0.36161 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.42927e-07 ( -3.60451e-08 3.59134e-08 ) ergs/cm2
Time-resolved spectra
