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 -15.912 sec. to 64.088 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.92237 ( -0.259919 0.243484 )
Norm@50keV : 1.48135E-03 ( -0.000241629 0.000234608 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.74 using 59 PHA bins.
# Reduced chi-squared = 0.9955 for 57 degrees of freedom
# Null hypothesis probability = 4.847326e-01
Photon flux (15-150 keV) in 80 sec: 0.214651 ( -0.029531 0.029564 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.09003e-06 ( -1.7062e-07 1.73482e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -15.912 sec. to 64.088 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.55577 ( -0.640703 1.03588 )
Epeak [keV] : 55.7980 ( -55.7481 -55.8 )
Norm@50keV : 2.34163E-03 ( -0.00129842 0.00601808 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.22 using 59 PHA bins.
# Reduced chi-squared = 1.004 for 56 degrees of freedom
# Null hypothesis probability = 4.666552e-01
Photon flux (15-150 keV) in 80 sec: 0.211685 ( -0.03039 0.03035 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.06189e-06 ( -1.81994e-07 1.84978e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 7.588 sec. to 8.588 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.72465 ( 2.72465 2.72465 )
Norm@50keV : 1.10113E-03 ( -0.00110113 0.00230534 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 67.92 using 59 PHA bins.
# Reduced chi-squared = 1.192 for 57 degrees of freedom
# Null hypothesis probability = 1.525725e-01
Photon flux (15-150 keV) in 1 sec: 0.249862 ( -0.249862 0.273535 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.18201e-08 ( 1 1.96951e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 7.588 sec. to 8.588 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.90334 ( )
Epeak [keV] : 3.86208 ( )
Norm@50keV : 3.86734E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 67.94 using 59 PHA bins.
# Reduced chi-squared = 1.213 for 56 degrees of freedom
# Null hypothesis probability = 1.316553e-01
Photon flux (15-150 keV) in 1 sec: 0.245748 ( -0.245748 0.270428 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.10375e-08 ( 0 0 ) ergs/cm2
Time-resolved spectra
