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 -87.040 sec. to 161.076 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.34878 ( -0.0583366 0.0585581 )
Norm@50keV : 2.54032E-03 ( -8.10466e-05 8.10457e-05 )
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#Fit statistic : Chi-Squared = 60.07 using 59 PHA bins.
# Reduced chi-squared = 1.054 for 57 degrees of freedom
# Null hypothesis probability = 3.652019e-01
Photon flux (15-150 keV) in 248.1 sec: 0.305962 ( -0.010476 0.0105 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.15797e-06 ( -2.10845e-07 2.11261e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -87.040 sec. to 161.076 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.05194 ( -0.230819 0.243665 )
Epeak [keV] : 172.337 ( -54.0354 361.58 )
Norm@50keV : 3.49868E-03 ( -0.000752747 0.00102037 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.18 using 59 PHA bins.
# Reduced chi-squared = 0.9854 for 56 degrees of freedom
# Null hypothesis probability = 5.057373e-01
Photon flux (15-150 keV) in 248.1 sec: 0.300546 ( -0.011227 0.011248 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.03054e-06 ( -2.3443e-07 2.33386e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.632 sec. to 1.632 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.748826 ( -0.184727 0.195106 )
Norm@50keV : 1.26117E-02 ( -0.00146579 0.00144 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.00 using 59 PHA bins.
# Reduced chi-squared = 1.088 for 57 degrees of freedom
# Null hypothesis probability = 3.023858e-01
Photon flux (15-150 keV) in 1 sec: 1.45293 ( -0.16059 0.16134 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.50664e-07 ( -1.63999e-08 1.64335e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.632 sec. to 1.632 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.341657 ( -0.515481 0.847454 )
Epeak [keV] : 253.383 ( -253.387 -253.387 )
Norm@50keV : 1.85105E-02 ( -0.00695557 0.0208913 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.09 using 59 PHA bins.
# Reduced chi-squared = 1.091 for 56 degrees of freedom
# Null hypothesis probability = 2.982625e-01
Photon flux (15-150 keV) in 1 sec: 1.43317 ( -0.16376 0.16477 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.48977e-07 ( -1.71179e-08 1.689e-08 ) ergs/cm2
Time-resolved spectra
