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 -0.832 sec. to 3.168 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.91282 ( -0.160385 0.154892 )
Norm@50keV : 1.71398E-02 ( -0.00173832 0.00171168 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 63.24 using 59 bins.
Reduced chi-squared = 1.10947
# Null hypothesis probability of 2.65e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 4 sec: 2.47340 ( -0.22361 0.22389 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.30508e-07 ( -6.23488e-08 6.29816e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.832 sec. to 3.168 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.32999 ( -0.674408 0.84025 )
Epeak [keV] : 51.2799 ( -16.3111 -51.2753 )
Norm@50keV : 3.60089E-02 ( -0.0194093 0.0694117 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 61.14 using 59 bins.
Reduced chi-squared = 1.09179
# Null hypothesis probability of 2.97e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 4 sec: 2.42077 ( -0.23358 0.2327 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.01588e-07 ( -7.16196e-08 7.1714e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.168 sec. to 1.168 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.85343 ( -0.177159 0.16996 )
Norm@50keV : 3.50346E-02 ( -0.00388038 0.00382008 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 58.36 using 59 bins.
Reduced chi-squared = 1.02386
# Null hypothesis probability of 4.25e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 4.93163 ( -0.50404 0.50478 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.22174e-07 ( -3.55253e-08 3.57493e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.168 sec. to 1.168 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.41964 ( -0.8068 0.843719 )
Epeak [keV] : 63.8578 ( -22.2027 -63.8564 )
Norm@50keV : 5.95113E-02 ( -0.0261577 0.106872 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 57.29 using 59 bins.
Reduced chi-squared = 1.02304
# Null hypothesis probability of 4.27e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 4.86070 ( -0.51885 0.51791 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.14355e-07 ( -3.84751e-08 3.81376e-08 ) ergs/cm2
Time-resolved spectra
