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 -9.124 sec. to 56.916 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.88667 ( -0.0620983 0.0615787 )
Norm@50keV : 5.86294E-03 ( -0.000198396 0.000197766 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 73.62 using 59 PHA bins.
# Reduced chi-squared = 1.292 for 57 degrees of freedom
# Null hypothesis probability = 6.841046e-02
Photon flux (15-150 keV) in 66.04 sec: 0.836722 ( -0.029241 0.029349 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.55998e-06 ( -1.19831e-07 1.20269e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -9.124 sec. to 56.916 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.37401 ( -0.26462 0.281655 )
Epeak [keV] : 59.4409 ( -7.26838 14.634 )
Norm@50keV : 1.06394E-02 ( -0.00275936 0.00404717 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.11 using 59 PHA bins.
# Reduced chi-squared = 1.109 for 56 degrees of freedom
# Null hypothesis probability = 2.676335e-01
Photon flux (15-150 keV) in 66.04 sec: 0.805040 ( -0.032896 0.033049 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.4039e-06 ( -1.42553e-07 1.42821e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -3.076 sec. to -2.076 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.597 ( -0.154924 0.15216 )
Norm@50keV : 1.78329E-02 ( -0.00162712 0.00161383 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.92 using 59 PHA bins.
# Reduced chi-squared = 0.7881 for 57 degrees of freedom
# Null hypothesis probability = 8.767827e-01
Photon flux (15-150 keV) in 1 sec: 2.28956 ( -0.2017 0.20194 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.66859e-07 ( -1.63127e-08 1.64779e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -3.076 sec. to -2.076 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.3525 ( -0.376383 0.647505 )
Epeak [keV] : 130.513 ( -63.8668 -130.513 )
Norm@50keV : 2.38185E-02 ( -0.0144294 0.0267058 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.40 using 59 PHA bins.
# Reduced chi-squared = 0.7929 for 56 degrees of freedom
# Null hypothesis probability = 8.682127e-01
Photon flux (15-150 keV) in 1 sec: 2.26524 ( -0.21015 0.20954 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.63817e-07 ( -1.80632e-08 1.79019e-08 ) ergs/cm2
Time-resolved spectra
