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 -0.016 sec. to 29.856 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.57166 ( -0.184875 0.182645 )
Norm@50keV : 2.19649E-03 ( -0.000246774 0.00024529 )
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#Fit statistic : Chi-Squared = 64.13 using 59 PHA bins.
# Reduced chi-squared = 1.125 for 57 degrees of freedom
# Null hypothesis probability = 2.408850e-01
Photon flux (15-150 keV) in 29.87 sec: 0.279845 ( -0.030725 0.030796 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.15893e-07 ( -7.40474e-08 7.50236e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.016 sec. to 29.856 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.313765 ( -0.841526 1.05251 )
Epeak [keV] : 63.2855 ( -11.9922 35.8908 )
Norm@50keV : 9.96299E-03 ( -0.00626168 0.0248162 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.99 using 59 PHA bins.
# Reduced chi-squared = 1.018 for 56 degrees of freedom
# Null hypothesis probability = 4.379510e-01
Photon flux (15-150 keV) in 29.87 sec: 0.263681 ( -0.032345 0.032458 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.52643e-07 ( -8.04435e-08 8.42922e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 24.096 sec. to 25.096 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.16338 ( -0.528555 0.577085 )
Norm@50keV : 4.41818E-03 ( -0.00132342 0.00131253 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 66.16 using 59 PHA bins.
# Reduced chi-squared = 1.161 for 57 degrees of freedom
# Null hypothesis probability = 1.900653e-01
Photon flux (15-150 keV) in 1 sec: 0.516091 ( -0.16038 0.162813 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.53064e-08 ( -1.41864e-08 1.44301e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 24.096 sec. to 25.096 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.531579 ( -8.05471 8.64422 )
Epeak [keV] : 123.028 ( -122.844 -122.844 )
Norm@50keV : 8.84831E-03 ( -0.00886787 38.6472 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 66.05 using 59 PHA bins.
# Reduced chi-squared = 1.179 for 56 degrees of freedom
# Null hypothesis probability = 1.685526e-01
Photon flux (15-150 keV) in 1 sec: 0.500175 ( -0.207882 0.167478 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.30844e-08 ( -1.8897e-08 1.6286e-08 ) ergs/cm2
Time-resolved spectra
