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 -1.240 sec. to 11.116 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.55602 ( -0.0889895 0.088314 )
Norm@50keV : 1.14325E-02 ( -0.000577842 0.000575419 )
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#Fit statistic : Chi-Squared = 48.39 using 59 PHA bins.
# Reduced chi-squared = 0.8489 for 57 degrees of freedom
# Null hypothesis probability = 7.846148e-01
Photon flux (15-150 keV) in 12.36 sec: 1.44986 ( -0.07081 0.07087 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.32932e-06 ( -7.36106e-08 7.42015e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.240 sec. to 11.116 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.14717 ( -0.356064 0.389692 )
Epeak [keV] : 100.068 ( -27.8379 284.551 )
Norm@50keV : 1.86173E-02 ( -0.0063082 0.010788 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.50 using 59 PHA bins.
# Reduced chi-squared = 0.7947 for 56 degrees of freedom
# Null hypothesis probability = 8.657930e-01
Photon flux (15-150 keV) in 12.36 sec: 1.41667 ( -0.07632 0.07626 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.2754e-06 ( -8.70972e-08 8.72908e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.944 sec. to 1.944 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.234 ( -0.141403 0.141705 )
Norm@50keV : 2.36362E-02 ( -0.00205498 0.00205325 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.68 using 59 PHA bins.
# Reduced chi-squared = 1.047 for 57 degrees of freedom
# Null hypothesis probability = 3.786134e-01
Photon flux (15-150 keV) in 1 sec: 2.78844 ( -0.2436 0.24379 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.37586e-07 ( -2.32229e-08 2.34618e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.944 sec. to 1.944 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.154358 ( -0.71641 0.859718 )
Epeak [keV] : 79.3900 ( -13.4203 31.9103 )
Norm@50keV : 0.113617 ( -0.0620511 0.176578 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.07 using 59 PHA bins.
# Reduced chi-squared = 0.8405 for 56 degrees of freedom
# Null hypothesis probability = 7.966457e-01
Photon flux (15-150 keV) in 1 sec: 2.64133 ( -0.25557 0.2552 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.15283e-07 ( -2.51927e-08 2.58963e-08 ) ergs/cm2
Time-resolved spectra
