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 -65.888 sec. to 195.912 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.62337 ( -0.0712831 0.0710292 )
Norm@50keV : 1.74187E-03 ( -6.69985e-05 6.68685e-05 )
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#Fit statistic : Chi-Squared = 49.25 using 59 PHA bins.
# Reduced chi-squared = 0.8640 for 57 degrees of freedom
# Null hypothesis probability = 7.575742e-01
Photon flux (15-150 keV) in 261.8 sec: 0.225497 ( -0.008976 0.008998 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.25373e-06 ( -1.73919e-07 1.74702e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -65.888 sec. to 195.912 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.34871 ( -0.274027 0.293756 )
Epeak [keV] : 118.169 ( -37.2308 1905.99 )
Norm@50keV : 2.38835E-03 ( -0.000623873 0.000934056 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 46.33 using 59 PHA bins.
# Reduced chi-squared = 0.8273 for 56 degrees of freedom
# Null hypothesis probability = 8.181732e-01
Photon flux (15-150 keV) in 261.8 sec: 0.221337 ( -0.009836 0.009852 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.14733e-06 ( -2.03851e-07 2.03374e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 7.524 sec. to 8.524 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.34307 ( -0.203346 0.202893 )
Norm@50keV : 1.06988E-02 ( -0.00122181 0.0012194 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.41 using 59 PHA bins.
# Reduced chi-squared = 0.9546 for 57 degrees of freedom
# Null hypothesis probability = 5.727679e-01
Photon flux (15-150 keV) in 1 sec: 1.28709 ( -0.1493 0.14962 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.04669e-07 ( -1.3346e-08 1.34909e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 7.524 sec. to 8.524 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.989291 ( -0.458049 0.843846 )
Epeak [keV] : 152.830 ( -152.828 -152.828 )
Norm@50keV : 1.57587E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.73 using 59 PHA bins.
# Reduced chi-squared = 0.9595 for 56 degrees of freedom
# Null hypothesis probability = 5.612349e-01
Photon flux (15-150 keV) in 1 sec: 1.26415 ( -0.15686 0.15663 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.02296e-07 ( -1.43431e-08 1.43393e-08 ) ergs/cm2
Time-resolved spectra
