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 1.508 sec. to 39.184 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.13329 ( -0.276406 0.254418 )
Norm@50keV : 1.37258E-03 ( -0.000251992 0.000243695 )
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#Fit statistic : Chi-Squared = 64.32 using 59 PHA bins.
# Reduced chi-squared = 1.128 for 57 degrees of freedom
# Null hypothesis probability = 2.357457e-01
Photon flux (15-150 keV) in 37.68 sec: 0.219579 ( -0.028788 0.028793 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.82281e-07 ( -7.67813e-08 7.89746e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.508 sec. to 39.184 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.98917 ( -0.0135251 1.04969 )
Epeak [keV] : 3.08674 ( -2.10237 -3.08674 )
Norm@50keV : 1.66785E-03 ( -0.000643069 0.00038526 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.26 using 59 PHA bins.
# Reduced chi-squared = 1.148 for 56 degrees of freedom
# Null hypothesis probability = 2.096082e-01
Photon flux (15-150 keV) in 37.68 sec: 0.219480 ( -0.028718 0.028989 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.749e-07 ( -8.7106e-08 8.6343e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 5.008 sec. to 6.008 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.26352 ( -0.656778 0.541795 )
Norm@50keV : 3.52993E-03 ( -0.00154539 0.00150508 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 69.78 using 59 PHA bins.
# Reduced chi-squared = 1.224 for 57 degrees of freedom
# Null hypothesis probability = 1.191376e-01
Photon flux (15-150 keV) in 1 sec: 0.604680 ( -0.17525 0.175296 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.35243e-08 ( -1.18193e-08 1.28343e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 5.008 sec. to 6.008 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.07978 ( -1.0393 4.2468 )
Epeak [keV] : 26.2770 ( )
Norm@50keV : 2.11528E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 69.43 using 59 PHA bins.
# Reduced chi-squared = 1.240 for 56 degrees of freedom
# Null hypothesis probability = 1.072432e-01
Photon flux (15-150 keV) in 1 sec: 0.600323 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Time-resolved spectra