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 -8.144 sec. to 10.812 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.97893 ( -0.238947 0.22298 )
Norm@50keV : 1.51625E-03 ( -0.000255455 0.000250574 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.67 using 59 PHA bins.
# Reduced chi-squared = 1.135 for 57 degrees of freedom
# Null hypothesis probability = 2.265903e-01
Photon flux (15-150 keV) in 18.96 sec: 0.225278 ( -0.028322 0.028327 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.64886e-07 ( -4.17202e-08 4.31971e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -8.144 sec. to 10.812 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.359943 ( -1.12817 1.49292 )
Epeak [keV] : 39.4461 ( -8.14345 11.7991 )
Norm@50keV : 1.42704E-02 ( -0.014269 0.104049 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.98 using 59 PHA bins.
# Reduced chi-squared = 1.035 for 56 degrees of freedom
# Null hypothesis probability = 4.020825e-01
Photon flux (15-150 keV) in 18.96 sec: 0.215334 ( -0.028346 0.028607 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.27928e-07 ( -3.90248e-08 4.54282e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.092 sec. to 1.092 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.85134 ( -0.478306 0.413971 )
Norm@50keV : 4.02285E-03 ( -0.00120787 0.0011265 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.66 using 59 PHA bins.
# Reduced chi-squared = 0.9414 for 57 degrees of freedom
# Null hypothesis probability = 6.012115e-01
Photon flux (15-150 keV) in 1 sec: 0.565795 ( -0.125124 0.125137 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.69947e-08 ( -1.04951e-08 1.1014e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.092 sec. to 1.092 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.7562 ( -0.653012 1.66791 )
Epeak [keV] : 115.833 ( )
Norm@50keV : 4.54213E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.64 using 59 PHA bins.
# Reduced chi-squared = 0.9579 for 56 degrees of freedom
# Null hypothesis probability = 5.645287e-01
Photon flux (15-150 keV) in 1 sec: 0.564114 ( -0.126343 0.126085 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.6686e-08 ( -1.08967e-08 9.66403e-09 ) ergs/cm2
Time-resolved spectra
