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 -111.000 sec. to 17.000 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.84237 ( -0.183502 0.177414 )
Norm@50keV : 1.02773E-03 ( -0.000118106 0.000115936 )
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#Fit statistic : Chi-Squared = 53.70 using 59 PHA bins.
# Reduced chi-squared = 0.9420 for 57 degrees of freedom
# Null hypothesis probability = 5.998148e-01
Photon flux (15-150 keV) in 128 sec: 0.144022 ( -0.014019 0.014026 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.2099e-06 ( -1.38282e-07 1.40803e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -111.000 sec. to 17.000 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.43617 ( -0.696678 0.85655 )
Epeak [keV] : 59.2018 ( -21.6448 -59.2022 )
Norm@50keV : 1.75042E-03 ( -0.000809404 0.00366974 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.75 using 59 PHA bins.
# Reduced chi-squared = 0.9419 for 56 degrees of freedom
# Null hypothesis probability = 5.987559e-01
Photon flux (15-150 keV) in 128 sec: 0.141447 ( -0.014741 0.014704 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.15383e-06 ( -1.66501e-07 1.69632e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -55.500 sec. to -54.500 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.17453 ( -0.712817 0.796575 )
Norm@50keV : 2.12742E-03 ( -0.00100097 0.000998274 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.44 using 59 PHA bins.
# Reduced chi-squared = 1.060 for 57 degrees of freedom
# Null hypothesis probability = 3.528376e-01
Photon flux (15-150 keV) in 1 sec: 0.248563 ( -0.116949 0.120765 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.17796e-08 ( -1.06648e-08 1.10382e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -55.500 sec. to -54.500 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 10 ( -9.22575 -10 )
Epeak [keV] : 40.9902 ( -6.13757 28.676 )
Norm@50keV : 7726.88 ( -7723.39 40907.8 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.54 using 59 PHA bins.
# Reduced chi-squared = 0.9918 for 56 degrees of freedom
# Null hypothesis probability = 4.921770e-01
Photon flux (15-150 keV) in 1 sec: 0.198287 ( -0.072465 0.102736 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.20343e-08 ( -4.41649e-09 9.58492e-09 ) ergs/cm2
Time-resolved spectra
