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 0.000 sec. to 6.400 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -0.897674 ( -0.324156 0.354728 )
Norm@50keV : 3.45723E-03 ( -0.000685694 0.00066892 )
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#Fit statistic : Chi-Squared = 37.66 using 59 PHA bins.
# Reduced chi-squared = 0.6607 for 57 degrees of freedom
# Null hypothesis probability = 9.775304e-01
Photon flux (15-150 keV) in 6.4 sec: 0.396802 ( -0.077354 0.078226 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.48565e-07 ( -4.71788e-08 4.74269e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 6.400 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -0.567929 ( -0.623423 1.58537 )
Epeak [keV] : 257.085 ( -257.184 -257.184 )
Norm@50keV : 4.79529E-03 ( -0.00194084 0.0166458 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 37.46 using 59 PHA bins.
# Reduced chi-squared = 0.6689 for 56 degrees of freedom
# Null hypothesis probability = 9.731465e-01
Photon flux (15-150 keV) in 6.4 sec: 0.391368 ( -0.079572 0.080557 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.44963e-07 ( -5.1017e-08 4.87551e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 1.900 sec. to 2.900 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.152 ( -0.564083 0.6256 )
Norm@50keV : 4.98253E-03 ( -0.00167336 0.00166525 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.91 using 59 PHA bins.
# Reduced chi-squared = 1.016 for 57 degrees of freedom
# Null hypothesis probability = 4.414658e-01
Photon flux (15-150 keV) in 1 sec: 0.581208 ( -0.200776 0.20318 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.12661e-08 ( -1.8156e-08 1.8562e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.900 sec. to 2.900 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.639791 ( -7.9888 2.11907 )
Epeak [keV] : 136.592 ( -136.662 -136.662 )
Norm@50keV : 8.95392E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.71 using 59 PHA bins.
# Reduced chi-squared = 1.030 for 56 degrees of freedom
# Null hypothesis probability = 4.119009e-01
Photon flux (15-150 keV) in 1 sec: 0.570641 ( -0.201967 0.206682 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.92527e-08 ( -2.12468e-08 1.98556e-08 ) ergs/cm2
Time-resolved spectra
