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 -23.288 sec. to 137.720 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.73614 ( -0.16265 0.158755 )
Norm@50keV : 9.60203E-04 ( -9.19358e-05 9.05229e-05 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.12 using 59 PHA bins.
# Reduced chi-squared = 1.072 for 57 degrees of freedom
# Null hypothesis probability = 3.302322e-01
Photon flux (15-150 keV) in 161 sec: 0.129184 ( -0.011154 0.01117 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.42789e-06 ( -1.41434e-07 1.43395e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -23.288 sec. to 137.720 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.73796 ( -0.16161 0.161574 )
Epeak [keV] : 9999.36 ( -9999.35 -9999.36 )
Norm@50keV : 9.60244E-04 ( -0.000510811 0.000995504 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.12 using 59 PHA bins.
# Reduced chi-squared = 1.092 for 56 degrees of freedom
# Null hypothesis probability = 2.971032e-01
Photon flux (15-150 keV) in 161 sec: 0.129372 ( -0.011536 0.011188 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.43181e-06 ( -1.66825e-07 1.09448e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -23.204 sec. to -22.204 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.858265 ( -0.0715141 0.0722173 )
Norm@50keV : 4.59502E-02 ( -0.00183377 0.00182691 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.91 using 59 PHA bins.
# Reduced chi-squared = 0.8406 for 57 degrees of freedom
# Null hypothesis probability = 7.988878e-01
Photon flux (15-150 keV) in 1 sec: 0.326929 0.291927 0.259697 0.231284 0.206441 0.184882 0.166298 0.150369 0.136775 0.125210 0.115390 0.107054 9.99746E-02 9.39515E-02 8.88139E-02 8.44174E-02 8.06408E-02 7.73827E-02 7.45596E-02 7.21019E-02 6.99525E-02 6.80638E-02 6.63967E-02 6.49187E-02 6.36025E-02 6.24255E-02 6.13689E-02 6.04167E-02 5.95555E-02 5.87737E-02 5.80619E-02 5.74116E-02 5.68158E-02 5.62683E-02 5.57640E-02 5.52981E-02 5.48668E-02 5.44665E-02 5.40943E-02 5.37473E-02 5.34233E-02 5.31201E-02 5.28360E-02 5.25692E-02 5.23184E-02 5.20820E-02 5.18591E-02 5.16485E-02 5.14493E-02 5.12607E-02 5.10817E-02 5.09119E-02 5.07504E-02 5.05966E-02 5.04502E-02 5.03094E-02 5.01732E-02 5.00416E-02 4.97930E-02 4.95603E-02 4.93424E-02 4.91383E-02 4.89469E-02 4.87674E-02 4.85989E-02 4.84407E-02 4.82919E-02 4.81520E-02 4.78985E-02 4.76729E-02 4.47484E-02 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 5.24312e-07 ( -2.27669e-08 2.28299e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -23.204 sec. to -22.204 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.851463 ( -0.071993 0.0728474 )
Epeak [keV] : 9999.35 ( -9999.34 -9999.34 )
Norm@50keV : 4.62650E-02 ( -0.00181688 0.0143756 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.91 using 59 PHA bins.
# Reduced chi-squared = 0.8555 for 56 degrees of freedom
# Null hypothesis probability = 7.707490e-01
Photon flux (15-150 keV) in 1 sec: 5.27153 ( -0.20711 0.2096 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.24047e-07 ( -1.95484e-08 2.2176e-08 ) ergs/cm2
Time-resolved spectra
