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 -1.804 sec. to 848.544 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.77485 ( -0.286875 0.272151 )
Norm@50keV : 3.01610E-04 ( -5.51669e-05 5.32909e-05 )
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#Fit statistic : Chi-Squared 58.52 using 59 bins.
Reduced chi-squared = 1.02667
# Null hypothesis probability of 4.20e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 850.3 sec: 4.11650E-02 ( -0.0060319 0.0060318 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.36376e-06 ( -4.34136e-07 4.49064e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.804 sec. to 848.544 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.77877 ( -0.71319 0.919922 )
Epeak [keV] : 9996.16 ( -9999.23 -9999.24 )
Norm@50keV : 2.99797E-04 ( -0.000301624 0.000739153 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 58.52 using 59 bins.
Reduced chi-squared = 1.045
# Null hypothesis probability of 3.83e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 850.3 sec: 3.69056E-02 ( -0.0100465 0.0086929 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.36332e-06 ( -3.46007e-07 4.48988e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.988 sec. to 1.988 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.53287 ( -0.24406 0.240277 )
Norm@50keV : 1.22489E-02 ( -0.00190974 0.00188839 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 89.18 using 59 bins.
Reduced chi-squared = 1.56456
# Null hypothesis probability of 4.12e-03 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 1.54311 ( -0.22766 0.22781 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.15617e-07 ( -1.94425e-08 1.97959e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.988 sec. to 1.988 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.450858 ( -1.12 1.485 )
Epeak [keV] : 63.6572 ( -16.8746 -63.5633 )
Norm@50keV : 4.87912E-02 ( -0.0490723 0.272947 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 86.51 using 59 bins.
Reduced chi-squared = 1.54482
# Null hypothesis probability of 5.52e-03 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 1.48928 ( -0.23532 0.23537 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.03727e-07 ( -2.13435e-08 2.31988e-08 ) ergs/cm2
Time-resolved spectra
