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 -15.000 sec. to 113.000 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -2.78118 ( -0.256811 0.233988 )
Norm@50keV : 6.01583E-04 ( -0.000115804 0.000118123 )
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#Fit statistic : Chi-Squared = 68.94 using 59 PHA bins.
# Reduced chi-squared = 1.209 for 57 degrees of freedom
# Null hypothesis probability = 1.335460e-01
Photon flux (15-150 keV) in 128 sec: 0.141818 ( -0.013953 0.013954 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.44054e-07 ( -1.02487e-07 1.06726e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -15.000 sec. to 113.000 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -0.408089 ( -1.60308 2.40335 )
Epeak [keV] : 20.4470 ( )
Norm@50keV : 2.51673E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 63.20 using 59 PHA bins.
# Reduced chi-squared = 1.128 for 56 degrees of freedom
# Null hypothesis probability = 2.372322e-01
Photon flux (15-150 keV) in 128 sec: 0.133445 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 7.11622e-07 ( -8.92506e-08 1.13503e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 8.500 sec. to 9.500 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -2.25498 ( -1.00136 0.757467 )
Norm@50keV : 1.81429E-03 ( -0.00115098 0.00119651 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 68.01 using 59 PHA bins.
# Reduced chi-squared = 1.193 for 57 degrees of freedom
# Null hypothesis probability = 1.507430e-01
Photon flux (15-150 keV) in 1 sec: 0.309256 ( -0.14085 0.141899 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.71728e-08 ( -9.0701e-09 1.04845e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 8.500 sec. to 9.500 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 10 ( -10.145 -10 )
Epeak [keV] : 25.2679 ( -3.78136 4.63102 )
Norm@50keV : 2.49796E+06 ( -2.49676e+06 1.39144e+07 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 63.76 using 59 PHA bins.
# Reduced chi-squared = 1.139 for 56 degrees of freedom
# Null hypothesis probability = 2.224579e-01
Photon flux (15-150 keV) in 1 sec: 0.284054 ( -0.104368 0.135208 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.10477e-08 ( -4.10673e-09 5.62017e-09 ) ergs/cm2
Time-resolved spectra
