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 -0.104 sec. to 19.420 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.89362 ( -0.208411 0.19817 )
Norm@50keV : 1.83460E-03 ( -0.000255293 0.000249775 )
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#Fit statistic : Chi-Squared = 48.65 using 59 PHA bins.
# Reduced chi-squared = 0.8536 for 57 degrees of freedom
# Null hypothesis probability = 7.764166e-01
Photon flux (15-150 keV) in 19.52 sec: 0.262590 ( -0.02876 0.028761 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.29275e-07 ( -4.4449e-08 4.56028e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.104 sec. to 19.420 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.22267 ( -0.824272 1.06656 )
Epeak [keV] : 46.6333 ( -41.6925 -46.6327 )
Norm@50keV : 4.58632E-03 ( -0.00289629 0.0156073 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 46.83 using 59 PHA bins.
# Reduced chi-squared = 0.8362 for 56 degrees of freedom
# Null hypothesis probability = 8.037877e-01
Photon flux (15-150 keV) in 19.52 sec: 0.256197 ( -0.029734 0.029803 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.0339e-07 ( -5.11752e-08 5.5243e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.114 sec. to 0.886 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.87121 ( -0.241359 0.22571 )
Norm@50keV : 7.39791E-03 ( -0.00122135 0.00119339 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 70.60 using 59 PHA bins.
# Reduced chi-squared = 1.239 for 57 degrees of freedom
# Null hypothesis probability = 1.063343e-01
Photon flux (15-150 keV) in 1 sec: 1.04900 ( -0.138462 0.13846 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.80221e-08 ( -1.0961e-08 1.12682e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.114 sec. to 0.886 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.135346 ( -1.27424 1.64604 )
Epeak [keV] : 43.6449 ( -7.75805 16.5217 )
Norm@50keV : 7.65090E-02 ( -0.0766121 0.626274 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.77 using 59 PHA bins.
# Reduced chi-squared = 1.157 for 56 degrees of freedom
# Null hypothesis probability = 1.973462e-01
Photon flux (15-150 keV) in 1 sec: 0.996988 ( -0.140573 0.142002 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.8401e-08 ( -1.0316e-08 1.22356e-08 ) ergs/cm2
Time-resolved spectra
