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 -10.248 sec. to 360.136 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.12523 ( -0.0774632 0.0783322 )
Norm@50keV : 4.02609E-03 ( -0.000177428 0.000176555 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 48.08 using 59 PHA bins.
# Reduced chi-squared = 0.8434 for 57 degrees of freedom
# Null hypothesis probability = 7.940528e-01
Photon flux (15-150 keV) in 370.4 sec: 0.468208 ( -0.022143 0.022244 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.547e-05 ( -6.58108e-07 6.58375e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -10.248 sec. to 360.136 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.11971 ( -0.0779692 0.09351 )
Epeak [keV] : 9998.14 ( -9998.34 -9998.34 )
Norm@50keV : 4.04705E-03 ( -0.000175046 0.000940077 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 48.10 using 59 PHA bins.
# Reduced chi-squared = 0.8590 for 56 degrees of freedom
# Null hypothesis probability = 7.644274e-01
Photon flux (15-150 keV) in 370.4 sec: 0.470585 ( -0.026067 0.021686 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.5495e-05 ( -9.82856e-07 6.7878e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.148 sec. to 0.852 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.994738 ( -0.145464 0.147903 )
Norm@50keV : 0.177852 ( -0.0152289 0.0151367 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.79 using 59 PHA bins.
# Reduced chi-squared = 1.102 for 57 degrees of freedom
# Null hypothesis probability = 2.785973e-01
Photon flux (15-150 keV) in 1 sec: 0.711033 ( -0.250754 0.753297 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.92699e-06 ( -1.69026e-07 1.69487e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.148 sec. to 0.852 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.988401 ( -0.146791 0.540612 )
Epeak [keV] : 9997.99 ( -9998.38 -9998.38 )
Norm@50keV : 0.178933 ( -0.0150578 0.118125 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.80 using 59 PHA bins.
# Reduced chi-squared = 1.121 for 56 degrees of freedom
# Null hypothesis probability = 2.480309e-01
Photon flux (15-150 keV) in 1 sec: 20.4876 ( -1.8471 1.817 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.92832e-06 ( -1.92679e-07 1.40201e-07 ) ergs/cm2
Time-resolved spectra
