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 -5.504 sec. to 143.368 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.29237 ( -0.0269513 0.0270263 )
Norm@50keV : 1.97692E-02 ( -0.000291084 0.000290653 )
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#Fit statistic : Chi-Squared = 36.43 using 59 PHA bins.
# Reduced chi-squared = 0.6391 for 57 degrees of freedom
# Null hypothesis probability = 9.845989e-01
Photon flux (15-150 keV) in 148.9 sec: 2.35526 ( -0.03988 0.04002 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.91464e-05 ( -4.08552e-07 4.08142e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -5.504 sec. to 143.368 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.16186 ( -0.110094 0.112738 )
Epeak [keV] : 404.430 ( -156.459 1541.95 )
Norm@50keV : 2.22747E-02 ( -0.00208388 0.0023569 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 32.37 using 59 PHA bins.
# Reduced chi-squared = 0.5780 for 56 degrees of freedom
# Null hypothesis probability = 9.952403e-01
Photon flux (15-150 keV) in 148.9 sec: 2.32835 ( -0.0452 0.0455 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.89911e-05 ( -4.28728e-07 4.28332e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 6.400 sec. to 7.400 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.959001 ( -0.0448149 0.0450581 )
Norm@50keV : 0.244432 ( -0.00641878 0.00640943 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 83.40 using 59 PHA bins.
# Reduced chi-squared = 1.463 for 57 degrees of freedom
# Null hypothesis probability = 1.289297e-02
Photon flux (15-150 keV) in 1 sec: 28.0909 ( -0.7485 0.749 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.68293e-06 ( -7.37142e-08 7.37097e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 6.400 sec. to 7.400 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.584711 ( -0.183153 0.190692 )
Epeak [keV] : 229.293 ( -56.7642 153.248 )
Norm@50keV : 0.351735 ( -0.0560477 0.0692425 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 70.76 using 59 PHA bins.
# Reduced chi-squared = 1.264 for 56 degrees of freedom
# Null hypothesis probability = 8.853009e-02
Photon flux (15-150 keV) in 1 sec: 27.6842 ( -0.7699 0.771 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.65399e-06 ( -7.61854e-08 7.60562e-08 ) ergs/cm2
Time-resolved spectra
