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 -130.612 sec. to 373.888 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.98959 ( -0.151615 0.145678 )
Norm@50keV : 6.45477E-04 ( -6.13197e-05 6.02093e-05 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 65.57 using 59 PHA bins.
# Reduced chi-squared = 1.150 for 57 degrees of freedom
# Null hypothesis probability = 2.039209e-01
Photon flux (15-150 keV) in 504.5 sec: 9.63680E-02 ( -0.0071139 0.007117 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.002e-06 ( -2.66789e-07 2.71866e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -130.612 sec. to 373.888 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.63464 ( -0.523302 0.706076 )
Epeak [keV] : 43.5024 ( -26.455 -43.5022 )
Norm@50keV : 1.02710E-03 ( -0.000531627 0.00155419 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.61 using 59 PHA bins.
# Reduced chi-squared = 1.154 for 56 degrees of freedom
# Null hypothesis probability = 2.010613e-01
Photon flux (15-150 keV) in 504.5 sec: 9.45813E-02 ( -0.0077499 0.0077307 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.88019e-06 ( -3.28717e-07 3.39626e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 310.568 sec. to 311.568 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.91253 ( -0.410395 0.366824 )
Norm@50keV : 3.85674E-03 ( -0.00108466 0.00104108 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.64 using 59 PHA bins.
# Reduced chi-squared = 1.134 for 57 degrees of freedom
# Null hypothesis probability = 2.272289e-01
Photon flux (15-150 keV) in 1 sec: 0.556485 ( -0.116811 0.116846 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.54683e-08 ( -9.35992e-09 9.85067e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 310.568 sec. to 311.568 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.38667 ( -0.777682 1.845 )
Epeak [keV] : 46.0731 ( )
Norm@50keV : 8.03422E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.24 using 59 PHA bins.
# Reduced chi-squared = 1.147 for 56 degrees of freedom
# Null hypothesis probability = 2.102817e-01
Photon flux (15-150 keV) in 1 sec: 0.548625 ( -0.117735 0.11857 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.3246e-08 ( -1.00774e-08 1.06495e-08 ) ergs/cm2
Time-resolved spectra
