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 -38.984 sec. to 38.600 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.28205 ( -0.0913393 0.092149 )
Norm@50keV : 8.20483E-03 ( -0.000418841 0.000417965 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.32 using 59 PHA bins.
# Reduced chi-squared = 1.023 for 57 degrees of freedom
# Null hypothesis probability = 4.264261e-01
Photon flux (15-150 keV) in 77.58 sec: 0.975705 ( -0.054252 0.054545 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.31888e-06 ( -3.32696e-07 3.3324e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -38.984 sec. to 38.600 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.2107 ( -0.0993887 0.364058 )
Epeak [keV] : 602.376 ( -998.611 -998.611 )
Norm@50keV : 8.81757E-03 ( -0.000707914 0.00361373 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.35 using 59 PHA bins.
# Reduced chi-squared = 1.042 for 56 degrees of freedom
# Null hypothesis probability = 3.891353e-01
Photon flux (15-150 keV) in 77.58 sec: 0.973586 ( -0.057536 0.053344 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.30753e-06 ( -3.43779e-07 3.35399e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 17.388 sec. to 18.388 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.39009 ( -0.27504 0.275052 )
Norm@50keV : 2.46418E-02 ( -0.00400574 0.00399476 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 74.59 using 59 PHA bins.
# Reduced chi-squared = 1.309 for 57 degrees of freedom
# Null hypothesis probability = 5.890228e-02
Photon flux (15-150 keV) in 1 sec: 2.99428 ( -0.50465 0.50635 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.38622e-07 ( -4.17427e-08 4.1986e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 17.388 sec. to 18.388 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.13362 ( -1.55692 1.29188 )
Epeak [keV] : 180.793 ( -180.835 -180.835 )
Norm@50keV : 3.28026E-02 ( -0.01191 0.0988501 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 74.43 using 59 PHA bins.
# Reduced chi-squared = 1.329 for 56 degrees of freedom
# Null hypothesis probability = 5.031863e-02
Photon flux (15-150 keV) in 1 sec: 2.96943 ( -0.51633 0.51672 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.35977e-07 ( -4.40748e-08 4.32645e-08 ) ergs/cm2
Time-resolved spectra
