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 -2.960 sec. to 197.056 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.42561 ( -0.0860033 0.0861292 )
Norm@50keV : 2.59488E-03 ( -0.000117211 0.000117211 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.13 using 59 PHA bins.
# Reduced chi-squared = 0.8970 for 57 degrees of freedom
# Null hypothesis probability = 6.939395e-01
Photon flux (15-150 keV) in 200 sec: 0.317901 ( -0.015709 0.015764 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.98976e-06 ( -2.40128e-07 2.40822e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -2.960 sec. to 197.056 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.42607 ( -0.0833598 0.0925807 )
Epeak [keV] : 9999.36 ( -9999.36 -9999.36 )
Norm@50keV : 2.60028E-03 ( -0.000117626 0.000490651 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.17 using 59 PHA bins.
# Reduced chi-squared = 0.9138 for 56 degrees of freedom
# Null hypothesis probability = 6.577414e-01
Photon flux (15-150 keV) in 200 sec: 0.317847 ( -0.015719 0.015758 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.98872e-06 ( -2.404e-07 2.40778e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.300 sec. to 0.700 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.17426 ( -0.241877 0.249532 )
Norm@50keV : 1.93871E-02 ( -0.00298383 0.00297525 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.90 using 59 PHA bins.
# Reduced chi-squared = 1.016 for 57 degrees of freedom
# Null hypothesis probability = 4.418486e-01
Photon flux (15-150 keV) in 1 sec: 2.26781 ( -0.3646 0.36733 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.98166e-07 ( -3.14605e-08 3.1597e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.300 sec. to 0.700 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.378087 ( -1.22556 1.75292 )
Epeak [keV] : 84.5716 ( -20.523 106.243 )
Norm@50keV : 9.95325E-02 ( -0.0995325 0.500902 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.91 using 59 PHA bins.
# Reduced chi-squared = 0.9448 for 56 degrees of freedom
# Null hypothesis probability = 5.926838e-01
Photon flux (15-150 keV) in 1 sec: 2.13832 ( -0.37713 0.38054 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.84306e-07 ( -3.51434e-08 3.46919e-08 ) ergs/cm2
Time-resolved spectra
