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 -4.296 sec. to 56.476 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.23213 ( -0.0313679 0.0314518 )
Norm@50keV : 1.63131E-02 ( -0.000270926 0.000270348 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 41.68 using 59 PHA bins.
# Reduced chi-squared = 0.7312 for 57 degrees of freedom
# Null hypothesis probability = 9.363271e-01
Photon flux (15-150 keV) in 60.77 sec: 1.92396 ( -0.03573 0.03588 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.96987e-06 ( -1.62119e-07 1.62229e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -4.296 sec. to 56.476 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.17987 ( -0.0153941 0.133283 )
Epeak [keV] : 966.079 ( -9680.9 -9680.9 )
Norm@50keV : 1.71354E-02 ( -0.000270049 0.00195393 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 42.10 using 59 PHA bins.
# Reduced chi-squared = 0.7519 for 56 degrees of freedom
# Null hypothesis probability = 9.156233e-01
Photon flux (15-150 keV) in 60.77 sec: 1.92315 ( -0.0403 0.03558 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.96756e-06 ( -1.58003e-07 1.61273e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 34.248 sec. to 35.248 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.37432 ( -0.068865 0.0686606 )
Norm@50keV : 4.91931E-02 ( -0.00194014 0.00193873 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.26 using 59 PHA bins.
# Reduced chi-squared = 1.075 for 57 degrees of freedom
# Null hypothesis probability = 3.258511e-01
Photon flux (15-150 keV) in 1 sec: 5.95692 ( -0.23913 0.23933 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.77958e-07 ( -2.09645e-08 2.10414e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 34.248 sec. to 35.248 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.985497 ( -0.272135 0.290851 )
Epeak [keV] : 136.545 ( -37.5421 179.793 )
Norm@50keV : 7.60110E-02 ( -0.0195129 0.0284675 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.14 using 59 PHA bins.
# Reduced chi-squared = 0.9846 for 56 degrees of freedom
# Null hypothesis probability = 5.074148e-01
Photon flux (15-150 keV) in 1 sec: 5.84869 ( -0.25022 0.25025 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.655e-07 ( -2.30543e-08 2.29274e-08 ) ergs/cm2
Time-resolved spectra
