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 -2.348 sec. to 16.868 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.71732 ( -0.203932 0.200371 )
Norm@50keV : 3.88920E-03 ( -0.000445151 0.000440874 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.53 using 59 PHA bins.
# Reduced chi-squared = 0.9392 for 57 degrees of freedom
# Null hypothesis probability = 6.059017e-01
Photon flux (15-150 keV) in 19.22 sec: 0.519716 ( -0.060023 0.060384 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.91326e-07 ( -8.17703e-08 8.22862e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -2.348 sec. to 16.868 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.71864 ( -0.20257 0.210784 )
Epeak [keV] : 9999.36 ( -9999.35 -9999.36 )
Norm@50keV : 3.89009E-03 ( -0.00271595 0.00394027 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.54 using 59 PHA bins.
# Reduced chi-squared = 0.9560 for 56 degrees of freedom
# Null hypothesis probability = 5.686732e-01
Photon flux (15-150 keV) in 19.22 sec: 0.522195 ( -0.070725 0.064958 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.9615e-07 ( -1.02879e-07 7.01224e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -1.392 sec. to -0.392 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.52957 ( -0.524193 0.535815 )
Norm@50keV : 6.45949E-03 ( -0.0018598 0.00185338 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 63.51 using 59 PHA bins.
# Reduced chi-squared = 1.114 for 57 degrees of freedom
# Null hypothesis probability = 2.578939e-01
Photon flux (15-150 keV) in 1 sec: 0.813003 ( -0.247059 0.251077 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.10014e-08 ( -1.84357e-08 1.87485e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.392 sec. to -0.392 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.37974 ( -0.963027 2.13668 )
Epeak [keV] : 202.273 ( -143.416 -143.416 )
Norm@50keV : 7.69757E-03 ( -0.00754074 0.104719 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 63.49 using 59 PHA bins.
# Reduced chi-squared = 1.134 for 56 degrees of freedom
# Null hypothesis probability = 2.293352e-01
Photon flux (15-150 keV) in 1 sec: 0.807734 ( -0.254086 0.255336 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.03768e-08 ( -2.05587e-08 1.92135e-08 ) ergs/cm2
Time-resolved spectra
