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
51.292000 81.080000
82.000000 318.940000
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.72835 ( -0.11553 0.113836 )
Norm@50keV : 9.84801E-04 ( -6.40128e-05 6.33251e-05 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.61 using 59 PHA bins.
# Reduced chi-squared = 0.9931 for 57 degrees of freedom
# Null hypothesis probability = 4.897052e-01
Photon flux (15-150 keV) in 266.7 sec: 0.132121 ( -0.007797 0.007809 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.42713e-06 ( -1.6492e-07 1.66828e-07 ) ergs/cm2
Cutoff power-law model
Multiple GTIs in the spectrum
tstart tstop
51.292000 81.080000
82.000000 318.940000
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.13228 ( -0.0705372 0.638104 )
Epeak [keV] : 52.2383 ( )
Norm@50keV : 6.17813E-04 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.07 using 59 PHA bins.
# Reduced chi-squared = 1.001 for 56 degrees of freedom
# Null hypothesis probability = 4.724066e-01
Photon flux (15-150 keV) in 266.7 sec: 0.133204 ( -0.008944 0.006781 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.4601e-06 ( -1.20441e-07 1.29798e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 202.828 sec. to 203.828 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.50413 ( -0.12484 0.123306 )
Norm@50keV : 1.66397E-02 ( -0.00120894 0.00120157 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.56 using 59 PHA bins.
# Reduced chi-squared = 1.010 for 57 degrees of freedom
# Null hypothesis probability = 4.541589e-01
Photon flux (15-150 keV) in 1 sec: 2.07966 ( -0.1452 0.14529 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.57765e-07 ( -1.26742e-08 1.28079e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 202.828 sec. to 203.828 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.23033 ( -0.336859 0.51688 )
Epeak [keV] : 138.437 ( )
Norm@50keV : 2.29803E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.57 using 59 PHA bins.
# Reduced chi-squared = 1.010 for 56 degrees of freedom
# Null hypothesis probability = 4.535879e-01
Photon flux (15-150 keV) in 1 sec: 2.05250 ( -0.15275 0.15199 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.54064e-07 ( -1.42567e-08 1.42228e-08 ) ergs/cm2
Time-resolved spectra
