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 -84.668 sec. to 26.348 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.93334 ( -0.144361 0.139737 )
Norm@50keV : 1.33307E-03 ( -0.000119449 0.000117395 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.30 using 59 PHA bins.
# Reduced chi-squared = 1.128 for 57 degrees of freedom
# Null hypothesis probability = 2.361537e-01
Photon flux (15-150 keV) in 111 sec: 0.194088 ( -0.013936 0.013942 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.36136e-06 ( -1.17152e-07 1.19156e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -84.668 sec. to 26.348 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.78511 ( -0.448014 0.557195 )
Epeak [keV] : 61.9635 ( )
Norm@50keV : 1.61787E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.05 using 59 PHA bins.
# Reduced chi-squared = 1.144 for 56 degrees of freedom
# Null hypothesis probability = 2.148604e-01
Photon flux (15-150 keV) in 111 sec: 0.192641 ( -0.014743 0.014703 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.33737e-06 ( -1.40899e-07 1.13445e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 2.728 sec. to 3.728 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.69736 ( -0.412698 0.381933 )
Norm@50keV : 4.65356E-03 ( -0.00123752 0.00119157 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 41.55 using 59 PHA bins.
# Reduced chi-squared = 0.7289 for 57 degrees of freedom
# Null hypothesis probability = 9.381908e-01
Photon flux (15-150 keV) in 1 sec: 0.617500 ( -0.139807 0.139816 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.31023e-08 ( -1.16603e-08 1.21004e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 2.728 sec. to 3.728 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.08553 ( -1.34799 1.93051 )
Epeak [keV] : 66.4798 ( )
Norm@50keV : 1.02365E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 41.01 using 59 PHA bins.
# Reduced chi-squared = 0.7323 for 56 degrees of freedom
# Null hypothesis probability = 9.335717e-01
Photon flux (15-150 keV) in 1 sec: 0.607498 ( -0.141569 0.141652 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.08131e-08 ( -1.22964e-08 1.31429e-08 ) ergs/cm2
Time-resolved spectra
