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 -6.548 sec. to 250.780 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.41459 ( -0.048216 0.0483438 )
Norm@50keV : 3.19188E-03 ( -7.85227e-05 7.8499e-05 )
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#Fit statistic : Chi-Squared = 51.47 using 59 PHA bins.
# Reduced chi-squared = 0.9029 for 57 degrees of freedom
# Null hypothesis probability = 6.818615e-01
Photon flux (15-150 keV) in 257.3 sec: 0.390025 ( -0.010855 0.010914 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.91334e-06 ( -2.0271e-07 2.02993e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -6.548 sec. to 250.780 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.41121 ( -0.0485912 0.151597 )
Epeak [keV] : 9997.35 ( -9997.86 -9997.86 )
Norm@50keV : 3.20325E-03 ( -7.85088e-05 0.000518118 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.49 using 59 PHA bins.
# Reduced chi-squared = 0.9194 for 56 degrees of freedom
# Null hypothesis probability = 6.461376e-01
Photon flux (15-150 keV) in 257.3 sec: 0.390824 ( -0.014436 0.012041 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.92664e-06 ( -2.57447e-07 1.63569e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 5.476 sec. to 6.476 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.16762 ( -0.061414 0.0616049 )
Norm@50keV : 6.14101E-02 ( -0.00213163 0.00213156 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.97 using 59 PHA bins.
# Reduced chi-squared = 0.8942 for 57 degrees of freedom
# Null hypothesis probability = 6.995474e-01
Photon flux (15-150 keV) in 1 sec: 0.431637 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 6.28941e-07 ( -2.42827e-08 2.4355e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 5.476 sec. to 6.476 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.838237 ( -0.244585 0.258923 )
Epeak [keV] : 193.743 ( -61.7349 358.286 )
Norm@50keV : 8.73607E-02 ( -0.0196567 0.0270685 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 45.59 using 59 PHA bins.
# Reduced chi-squared = 0.8141 for 56 degrees of freedom
# Null hypothesis probability = 8.383933e-01
Photon flux (15-150 keV) in 1 sec: 7.06805 ( -0.2686 0.26866 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.16311e-07 ( -2.6436e-08 2.62731e-08 ) ergs/cm2
Time-resolved spectra
