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 -1.144 sec. to 28.232 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.68664 ( -0.336293 0.316028 )
Norm@50keV : 9.44654E-04 ( -0.000200596 0.000194288 )
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#Fit statistic : Chi-Squared = 60.89 using 59 PHA bins.
# Reduced chi-squared = 1.068 for 57 degrees of freedom
# Null hypothesis probability = 3.376636e-01
Photon flux (15-150 keV) in 29.38 sec: 0.124886 ( -0.022431 0.022431 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.57283e-07 ( -5.63129e-08 5.83857e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.144 sec. to 28.232 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.934219 ( -1.28329 2.49556 )
Epeak [keV] : 60.3538 ( -42.1778 -60.3416 )
Norm@50keV : 2.53821E-03 ( -0.00253983 0.0767081 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.18 using 59 PHA bins.
# Reduced chi-squared = 1.075 for 56 degrees of freedom
# Null hypothesis probability = 3.270028e-01
Photon flux (15-150 keV) in 29.38 sec: 0.121178 ( -0.0239293 0.02365 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.35311e-07 ( -6.71862e-08 7.13382e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 2.612 sec. to 3.612 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.33317 ( -0.518051 0.51285 )
Norm@50keV : 3.32997E-03 ( -0.00103035 0.00102041 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.32 using 59 PHA bins.
# Reduced chi-squared = 1.006 for 57 degrees of freedom
# Null hypothesis probability = 4.633216e-01
Photon flux (15-150 keV) in 1 sec: 0.399806 ( -0.121616 0.121841 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.26528e-08 ( -1.11111e-08 1.14992e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 2.612 sec. to 3.612 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.570756 ( -1.20787 2.47772 )
Epeak [keV] : 95.5869 ( -95.868 -95.868 )
Norm@50keV : 7.99986E-03 ( -0.00796001 0.111948 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.76 using 59 PHA bins.
# Reduced chi-squared = 1.013 for 56 degrees of freedom
# Null hypothesis probability = 4.466706e-01
Photon flux (15-150 keV) in 1 sec: 0.389624 ( -0.123302 0.123895 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.10749e-08 ( -1.15108e-08 1.20601e-08 ) ergs/cm2
Time-resolved spectra
