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 -7.568 sec. to 167.596 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.33513 ( -0.0617006 0.0619154 )
Norm@50keV : 4.86468E-03 ( -0.00015442 0.000154401 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.14 using 59 PHA bins.
# Reduced chi-squared = 0.9323 for 57 degrees of freedom
# Null hypothesis probability = 6.205363e-01
Photon flux (15-150 keV) in 175.2 sec: 0.584299 ( -0.02016 0.020245 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.35322e-06 ( -2.85254e-07 2.85991e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -7.568 sec. to 167.596 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.3317 ( -0.0619227 0.0736273 )
Epeak [keV] : 9998.40 ( -9998.7 -9998.7 )
Norm@50keV : 4.88189E-03 ( -0.000154857 0.000567144 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.17 using 59 PHA bins.
# Reduced chi-squared = 0.9494 for 56 degrees of freedom
# Null hypothesis probability = 5.828217e-01
Photon flux (15-150 keV) in 175.2 sec: 0.586363 ( -0.030574 0.025044 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.38213e-06 ( -3.35126e-07 2.70221e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.372 sec. to 1.372 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.841377 ( -0.106099 0.107581 )
Norm@50keV : 5.52901E-02 ( -0.00322008 0.00320711 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 42.51 using 59 PHA bins.
# Reduced chi-squared = 0.7458 for 57 degrees of freedom
# Null hypothesis probability = 9.234892e-01
Photon flux (15-150 keV) in 1 sec: 6.34763 ( -0.3658 0.36646 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.35214e-07 ( -4.01687e-08 4.03243e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.372 sec. to 1.372 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.834203 ( -0.107062 0.328602 )
Epeak [keV] : 9998.48 ( -9998.71 -9998.71 )
Norm@50keV : 5.56700E-02 ( -0.00318302 0.0197362 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 42.53 using 59 PHA bins.
# Reduced chi-squared = 0.7595 for 56 degrees of freedom
# Null hypothesis probability = 9.077890e-01
Photon flux (15-150 keV) in 1 sec: 6.34570 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 6.35814e-07 ( -4.40071e-08 3.24684e-08 ) ergs/cm2
Time-resolved spectra
