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 -159.472 sec. to 154.176 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.74896 ( -0.0491411 0.0489459 )
Norm@50keV : 1.02716E-02 ( -0.000253383 0.000253176 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 43.03 using 59 PHA bins.
# Reduced chi-squared = 0.7548 for 57 degrees of freedom
# Null hypothesis probability = 9.147120e-01
Photon flux (15-150 keV) in 313.6 sec: 1.38843 ( -0.03937 0.03958 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.97294e-05 ( -7.48892e-07 7.49968e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -159.472 sec. to 154.176 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.55839 ( -0.192362 0.202415 )
Epeak [keV] : 124.379 ( -37.9665 3900.63 )
Norm@50keV : 1.25852E-02 ( -0.00212818 0.0029483 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 40.22 using 59 PHA bins.
# Reduced chi-squared = 0.7182 for 56 degrees of freedom
# Null hypothesis probability = 9.447139e-01
Photon flux (15-150 keV) in 313.6 sec: 1.36390 ( -0.04591 0.04631 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.92864e-05 ( -8.72827e-07 8.69051e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -138.276 sec. to -137.276 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.57337 ( -0.107971 0.107283 )
Norm@50keV : 5.22230E-02 ( -0.0031216 0.00311284 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.99 using 59 PHA bins.
# Reduced chi-squared = 0.9472 for 57 degrees of freedom
# Null hypothesis probability = 5.887150e-01
Photon flux (15-150 keV) in 1 sec: 6.65692 ( -0.40951 0.41084 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.90117e-07 ( -3.13629e-08 3.15219e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -138.276 sec. to -137.276 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.57119 ( -0.133322 0.31009 )
Epeak [keV] : 1.00000E+04 ( -10000 -10000 )
Norm@50keV : 5.23568E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.00 using 59 PHA bins.
# Reduced chi-squared = 0.9642 for 56 degrees of freedom
# Null hypothesis probability = 5.510336e-01
Photon flux (15-150 keV) in 1 sec: 6.68408 ( -0.55532 0.49632 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.92516e-07 ( -4.59969e-08 4.01562e-08 ) ergs/cm2
Time-resolved spectra
