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 0.768 sec. to 53.940 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.58977 ( -0.0523504 0.0523032 )
Norm@50keV : 8.67504E-03 ( -0.000233633 0.000233562 )
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#Fit statistic : Chi-Squared = 55.99 using 59 PHA bins.
# Reduced chi-squared = 0.9823 for 57 degrees of freedom
# Null hypothesis probability = 5.128854e-01
Photon flux (15-150 keV) in 53.17 sec: 1.11132 ( -0.03351 0.03368 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.31973e-06 ( -1.21789e-07 1.21941e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.768 sec. to 53.940 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.58828 ( -0.0521394 0.053186 )
Epeak [keV] : 9999.36 ( -9999.36 -9999.36 )
Norm@50keV : 8.68955E-03 ( -0.000233968 0.00159803 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.01 using 59 PHA bins.
# Reduced chi-squared = 1.000 for 56 degrees of freedom
# Null hypothesis probability = 4.745863e-01
Photon flux (15-150 keV) in 53.17 sec: 1.11354 ( -0.04262 0.03627 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.3276e-06 ( -1.49806e-07 1.32935e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 32.752 sec. to 33.752 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.2205 ( -0.0616772 0.0618537 )
Norm@50keV : 8.66305E-02 ( -0.00291148 0.00291074 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 63.86 using 59 PHA bins.
# Reduced chi-squared = 1.120 for 57 degrees of freedom
# Null hypothesis probability = 2.480569e-01
Photon flux (15-150 keV) in 1 sec: 0.529213 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 8.73997e-07 ( -3.20011e-08 3.20693e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 32.752 sec. to 33.752 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.21732 ( -0.0612805 0.0633454 )
Epeak [keV] : 9999.36 ( -9999.36 -9999.36 )
Norm@50keV : 8.68671E-02 ( -0.00291977 0.0182317 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 63.90 using 59 PHA bins.
# Reduced chi-squared = 1.141 for 56 degrees of freedom
# Null hypothesis probability = 2.188651e-01
Photon flux (15-150 keV) in 1 sec: 10.2171 ( -0.58125 0.4064 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.75649e-07 ( -4.34255e-08 3.94119e-08 ) ergs/cm2
Time-resolved spectra
