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 -9.628 sec. to 8.872 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.41705 ( -0.192071 0.189279 )
Norm@50keV : 2.60814E-03 ( -0.000300892 0.000298742 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 55.07 using 59 bins.
Reduced chi-squared = 0.96614
# Null hypothesis probability of 5.48e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 18.5 sec: 0.318879 ( -0.035436 0.035455 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.647e-07 ( -6.00197e-08 6.09686e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -9.628 sec. to 8.872 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.38705 ( -0.852988 1.06615 )
Epeak [keV] : 77.4842 ( -18.2712 122.366 )
Norm@50keV : 8.65316E-03 ( -0.00537162 0.0200663 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 50.69 using 59 bins.
Reduced chi-squared = 0.905179
# Null hypothesis probability of 6.76e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 18.5 sec: 0.304566 ( -0.037652 0.037457 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.28127e-07 ( -6.45204e-08 6.7348e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 1.876 sec. to 2.876 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.2205 ( -0.412298 0.408046 )
Norm@50keV : 5.41380E-03 ( -0.00128756 0.00128352 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 44.57 using 59 bins.
Reduced chi-squared = 0.78193
# Null hypothesis probability of 8.85e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 0.637368 ( -0.151567 0.151814 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.46185e-08 ( -1.46636e-08 1.50313e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.876 sec. to 2.876 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.166166 ( -1.58782 3.90814 )
Epeak [keV] : 84.2892 ( -29.4332 -83.7668 )
Norm@50keV : 2.39772E-02 ( -0.0247485 1.31549 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 43.19 using 59 bins.
Reduced chi-squared = 0.77125
# Null hypothesis probability of 8.95e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 0.598702 ( -0.168707 0.163188 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.03211e-08 ( -1.56937e-08 1.63949e-08 ) ergs/cm2
Time-resolved spectra
