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 -99.388 sec. to 236.964 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.54878 ( -0.103006 0.102331 )
Norm@50keV : 1.05383E-03 ( -6.51611e-05 6.49376e-05 )
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#Fit statistic : Chi-Squared = 59.22 using 59 PHA bins.
# Reduced chi-squared = 1.039 for 57 degrees of freedom
# Null hypothesis probability = 3.944151e-01
Photon flux (15-150 keV) in 336.4 sec: 0.133366 ( -0.008133 0.008142 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.33838e-06 ( -2.23039e-07 2.247e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -99.388 sec. to 236.964 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.75315 ( -0.455087 0.509432 )
Epeak [keV] : 75.5337 ( -13.4052 37.8574 )
Norm@50keV : 2.72069E-03 ( -0.00112147 0.00222029 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.65 using 59 PHA bins.
# Reduced chi-squared = 0.8866 for 56 degrees of freedom
# Null hypothesis probability = 7.124253e-01
Photon flux (15-150 keV) in 336.4 sec: 0.128590 ( -0.008568 0.008564 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.12245e-06 ( -2.51701e-07 2.5435e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 198.840 sec. to 199.840 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.02255 ( -0.265029 0.278247 )
Norm@50keV : 5.33386E-03 ( -0.000921252 0.000917307 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.67 using 59 PHA bins.
# Reduced chi-squared = 0.9767 for 57 degrees of freedom
# Null hypothesis probability = 5.249357e-01
Photon flux (15-150 keV) in 1 sec: 0.614868 ( -0.107951 0.108527 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.72308e-08 ( -1.0263e-08 1.03386e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 198.840 sec. to 199.840 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.99129 ( -1.97068 3.39522 )
Epeak [keV] : 73.7237 ( -12.4783 34.501 )
Norm@50keV : 0.114795 ( -0.121567 2.77022 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.03 using 59 PHA bins.
# Reduced chi-squared = 0.8399 for 56 degrees of freedom
# Null hypothesis probability = 7.976906e-01
Photon flux (15-150 keV) in 1 sec: 0.543063 ( -0.116844 0.119272 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.87663e-08 ( -1.09917e-08 1.17274e-08 ) ergs/cm2
Time-resolved spectra
