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
Multiple GTIs in the spectrum
tstart tstop
-54.000000 235.376500
236.936000 250.104000
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.89968 ( -0.0752047 0.0742968 )
Norm@50keV : 2.28399E-03 ( -9.82358e-05 9.76494e-05 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 67.85 using 59 bins.
Reduced chi-squared = 1.19035
# Null hypothesis probability of 1.54e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 302.5 sec: 0.327753 ( -0.013218 0.013246 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.35295e-06 ( -2.69848e-07 2.71276e-07 ) ergs/cm2
Cutoff power-law model
Multiple GTIs in the spectrum
tstart tstop
-54.000000 235.376500
236.936000 250.104000
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.38891 ( -0.314871 0.342353 )
Epeak [keV] : 54.5230 ( -7.88473 18.2664 )
Norm@50keV : 4.27759E-03 ( -0.00134688 0.00220658 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 59.81 using 59 bins.
Reduced chi-squared = 1.06804
# Null hypothesis probability of 3.39e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 302.5 sec: 0.317070 ( -0.014627 0.014646 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.03013e-06 ( -3.28412e-07 3.29994e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 1.052 sec. to 2.052 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.43888 ( -0.217797 0.215909 )
Norm@50keV : 1.78182E-02 ( -0.00231504 0.00230814 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 61.34 using 59 bins.
Reduced chi-squared = 1.07614
# Null hypothesis probability of 3.23e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 2.18990 ( -0.28947 0.29008 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.7088e-07 ( -2.40956e-08 2.42617e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.052 sec. to 2.052 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.94673 ( -0.657812 1.0244 )
Epeak [keV] : 113.315 ( -46.0375 -113.315 )
Norm@50keV : 3.08946E-02 ( -0.0148833 0.0623197 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 60.38 using 59 bins.
Reduced chi-squared = 1.07821
# Null hypothesis probability of 3.20e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 2.15085 ( -0.29909 0.29797 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.66948e-07 ( -2.53393e-08 2.5308e-08 ) ergs/cm2
Time-resolved spectra
