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
-19.208000 21.400100
22.288000 117.368000
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.50261 ( -0.0422653 0.042262 )
Norm@50keV : 1.22210E-02 ( -0.000271842 0.000271828 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.00 using 59 PHA bins.
# Reduced chi-squared = 0.9123 for 57 degrees of freedom
# Null hypothesis probability = 6.626207e-01
Photon flux (15-150 keV) in 135.7 sec: 1.52677 ( -0.03881 0.03895 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.57275e-05 ( -3.60821e-07 3.61535e-07 ) ergs/cm2
Cutoff power-law model
Multiple GTIs in the spectrum
tstart tstop
-19.208000 21.400100
22.288000 117.368000
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.3241 ( -0.163955 0.173199 )
Epeak [keV] : 215.353 ( -78.1291 1510.32 )
Norm@50keV : 1.46613E-02 ( -0.00216559 0.00275233 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 48.68 using 59 PHA bins.
# Reduced chi-squared = 0.8692 for 56 degrees of freedom
# Null hypothesis probability = 7.456440e-01
Photon flux (15-150 keV) in 135.7 sec: 1.50504 ( -0.04327 0.04351 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.55636e-05 ( -3.9342e-07 3.9191e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 6.420 sec. to 7.420 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.03015 ( -0.155657 0.159704 )
Norm@50keV : 5.58294E-02 ( -0.0054997 0.00547322 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.49 using 59 PHA bins.
# Reduced chi-squared = 0.9735 for 57 degrees of freedom
# Null hypothesis probability = 5.319338e-01
Photon flux (15-150 keV) in 1 sec: 0.197247 0.218492 0.158693 0.115822 8.75817E-02 6.95516E-02 5.81314E-02 5.08007E-02 4.59625E-02 4.26571E-02 4.03172E-02 3.86042E-02 3.73122E-02 3.63118E-02 3.55193E-02 3.48789E-02 3.39191E-02 3.32324E-02 3.23260E-02 3.16925E-02 2.94414E-02 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 5.97448e-07 ( -5.99832e-08 6.00887e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 6.420 sec. to 7.420 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.288481 ( -0.690829 0.826875 )
Epeak [keV] : 137.367 ( -43.426 754.396 )
Norm@50keV : 0.117050 ( -0.0575115 0.139533 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.13 using 59 PHA bins.
# Reduced chi-squared = 0.9309 for 56 degrees of freedom
# Null hypothesis probability = 6.221417e-01
Photon flux (15-150 keV) in 1 sec: 6.30583 ( -0.66229 0.66489 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.88274e-07 ( -6.26805e-08 6.20503e-08 ) ergs/cm2
Time-resolved spectra