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 -0.120 sec. to 11.880 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -2.03061 ( -0.137789 0.132559 )
Norm@50keV : 8.88649E-03 ( -0.000809824 0.000798624 )
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#Fit statistic : Chi-Squared = 90.69 using 59 PHA bins.
# Reduced chi-squared = 1.591 for 57 degrees of freedom
# Null hypothesis probability = 3.007259e-03
Photon flux (15-150 keV) in 12 sec: 1.35219 ( -0.10071 0.10077 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.85374e-07 ( -8.3738e-08 8.47922e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.120 sec. to 11.880 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.775417 ( -0.70867 0.861485 )
Epeak [keV] : 40.0953 ( -6.28147 7.01425 )
Norm@50keV : 4.73217E-02 ( -0.028753 0.105022 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 80.30 using 59 PHA bins.
# Reduced chi-squared = 1.434 for 56 degrees of freedom
# Null hypothesis probability = 1.829973e-02
Photon flux (15-150 keV) in 12 sec: 1.29015 ( -0.10546 0.10589 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.81681e-07 ( -9.23279e-08 9.79474e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 1.880 sec. to 2.880 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.8697 ( -0.226112 0.211614 )
Norm@50keV : 1.80287E-02 ( -0.0029241 0.00286686 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 79.61 using 59 PHA bins.
# Reduced chi-squared = 1.397 for 57 degrees of freedom
# Null hypothesis probability = 2.563886e-02
Photon flux (15-150 keV) in 1 sec: 2.55482 ( -0.34886 0.3489 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.65764e-07 ( -2.64291e-08 2.68687e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.880 sec. to 2.880 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.501238 ( -1.43495 2.25263 )
Epeak [keV] : 43.2104 ( -6.12201 10.5987 )
Norm@50keV : 0.437649 ( -0.45185 9.80023 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 69.49 using 59 PHA bins.
# Reduced chi-squared = 1.241 for 56 degrees of freedom
# Null hypothesis probability = 1.062866e-01
Photon flux (15-150 keV) in 1 sec: 2.47245 ( -0.35215 0.35269 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.43747e-07 ( -2.53284e-08 2.82021e-08 ) ergs/cm2
Time-resolved spectra
