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 -21.256 sec. to 74.808 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.8987 ( -0.288473 0.268844 )
Norm@50keV : 1.70815E-03 ( -0.000300979 0.000289378 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.09 using 59 PHA bins.
# Reduced chi-squared = 1.002 for 57 degrees of freedom
# Null hypothesis probability = 4.717076e-01
Photon flux (15-150 keV) in 96.06 sec: 0.245017 ( -0.034949 0.034978 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.50877e-06 ( -2.54896e-07 2.60661e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -21.256 sec. to 74.808 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.21168 ( -0.100588 1.21906 )
Epeak [keV] : 85.5365 ( )
Norm@50keV : 1.17979E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.06 using 59 PHA bins.
# Reduced chi-squared = 1.019 for 56 degrees of freedom
# Null hypothesis probability = 4.356268e-01
Photon flux (15-150 keV) in 96.06 sec: 0.235752 ( -0.060496 0.044192 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.46569e-06 ( -3.61506e-07 2.34791e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 4.860 sec. to 5.860 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.4556 ( -0.944236 1.05044 )
Norm@50keV : 6.05799E-03 ( -0.00261396 0.00250643 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.11 using 59 PHA bins.
# Reduced chi-squared = 0.9318 for 57 degrees of freedom
# Null hypothesis probability = 6.217629e-01
Photon flux (15-150 keV) in 1 sec: 0.747437 ( -0.747437 0.337573 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.79322e-08 ( -2.60814e-08 2.62383e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 4.860 sec. to 5.860 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.40839 ( 2.4094 2.20641 )
Epeak [keV] : 141.192 ( )
Norm@50keV : 1.93501E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.19 using 59 PHA bins.
# Reduced chi-squared = 0.9320 for 56 degrees of freedom
# Null hypothesis probability = 6.198031e-01
Photon flux (15-150 keV) in 1 sec: 0.392419 ( -0.392419 0.470452 ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Time-resolved spectra
