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 -1.552 sec. to 3.624 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -2.0018 ( -0.471111 0.40935 )
Norm@50keV : 1.47000E-03 ( -0.000471453 0.000454014 )
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#Fit statistic : Chi-Squared = 37.16 using 59 PHA bins.
# Reduced chi-squared = 0.6519 for 57 degrees of freedom
# Null hypothesis probability = 9.806735e-01
Photon flux (15-150 keV) in 5.176 sec: 0.220700 ( -0.049836 0.049878 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.01866e-08 ( -2.0193e-08 2.17026e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.552 sec. to 3.624 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -0.82335 ( -1.31352 2.95717 )
Epeak [keV] : 37.6607 ( -37.6582 -37.6582 )
Norm@50keV : 7.83213E-03 ( -0.00788713 0.604097 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 36.13 using 59 PHA bins.
# Reduced chi-squared = 0.6453 for 56 degrees of freedom
# Null hypothesis probability = 9.819378e-01
Photon flux (15-150 keV) in 5.176 sec: 0.213340 ( -0.049691 0.050853 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.14091e-08 ( -1.87831e-08 2.57644e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.208 sec. to 0.792 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.52382 ( -0.413482 0.400995 )
Norm@50keV : 3.71871E-03 ( -0.00100002 0.00097964 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.97 using 59 PHA bins.
# Reduced chi-squared = 0.9995 for 57 degrees of freedom
# Null hypothesis probability = 4.760547e-01
Photon flux (15-150 keV) in 1 sec: 0.467286 ( -0.115436 0.115478 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.51536e-08 ( -1.00665e-08 1.04995e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.208 sec. to 0.792 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.475826 ( -2.14389 3.62978 )
Epeak [keV] : 51.2991 ( -13.6941 -51.0936 )
Norm@50keV : 5.29841E-02 ( -0.055424 6.19363 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.62 using 59 PHA bins.
# Reduced chi-squared = 0.9753 for 56 degrees of freedom
# Null hypothesis probability = 5.272712e-01
Photon flux (15-150 keV) in 1 sec: 0.437714 ( -0.116352 0.119316 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.82872e-08 ( -8.99641e-09 1.25786e-08 ) ergs/cm2
Time-resolved spectra
