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 -1.880 sec. to 16.224 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.12451 ( -0.0570624 0.0564127 )
Norm@50keV : 1.72613E-02 ( -0.000547172 0.000544994 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 75.93 using 59 bins.
Reduced chi-squared = 1.33211
# Null hypothesis probability of 4.76e-02 with 57 degrees of freedom
Photon flux (15-150 keV) in 18.1 sec: 2.74922 ( -0.08974 0.09016 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.91064e-06 ( -8.62275e-08 8.63698e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.880 sec. to 16.224 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.43858 ( -0.25202 0.267449 )
Epeak [keV] : 39.1364 ( -6.90051 4.71449 )
Norm@50keV : 3.86519E-02 ( -0.00974663 0.0140964 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 52.21 using 59 bins.
Reduced chi-squared = 0.932321
# Null hypothesis probability of 6.19e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 18.1 sec: 2.60241 ( -0.10134 0.1021 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.75384e-06 ( -1.01445e-07 1.01634e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.460 sec. to 0.540 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.72946 ( -0.0643496 0.063622 )
Norm@50keV : 8.45686E-02 ( -0.00330055 0.00329412 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 77.38 using 59 bins.
Reduced chi-squared = 1.35754
# Null hypothesis probability of 3.75e-02 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 11.3502 ( -0.4555 0.4564 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.81448e-07 ( -3.13984e-08 3.14574e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.460 sec. to 0.540 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.885037 ( -0.285529 0.303718 )
Epeak [keV] : 69.0452 ( -6.72334 10.6835 )
Norm@50keV : 0.217544 ( -0.0583381 0.086016 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 48.98 using 59 bins.
Reduced chi-squared = 0.874643
# Null hypothesis probability of 7.35e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 10.0130 ( -0.62216 0.7288 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.52991e-07 ( -3.32438e-08 3.32216e-08 ) ergs/cm2
Time-resolved spectra
