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 -0.728 sec. to 2.724 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.81522 ( -0.248688 0.236289 )
Norm@50keV : 3.09043E-03 ( -0.000533724 0.00052449 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.54 using 59 PHA bins.
# Reduced chi-squared = 1.097 for 57 degrees of freedom
# Null hypothesis probability = 2.861251e-01
Photon flux (15-150 keV) in 3.452 sec: 0.428417 ( -0.06229 0.062295 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.81728e-08 ( -1.6899e-08 1.73747e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.728 sec. to 2.724 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.40477 ( -1.33674 1.71603 )
Epeak [keV] : 43.6273 ( -6.98248 11.6466 )
Norm@50keV : 6.21156E-02 ( -0.0625673 0.573701 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.33 using 59 PHA bins.
# Reduced chi-squared = 0.9523 for 56 degrees of freedom
# Null hypothesis probability = 5.765859e-01
Photon flux (15-150 keV) in 3.452 sec: 0.405077 ( -0.061773 0.062394 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.18373e-08 ( -1.4773e-08 1.71891e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.100 sec. to 0.900 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.63671 ( -0.36093 0.343479 )
Norm@50keV : 4.15299E-03 ( -0.00097286 0.000951044 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 35.74 using 59 PHA bins.
# Reduced chi-squared = 0.6270 for 57 degrees of freedom
# Null hypothesis probability = 9.877017e-01
Photon flux (15-150 keV) in 1 sec: 0.539945 ( -0.113817 0.113868 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.86839e-08 ( -9.43295e-09 9.73222e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.100 sec. to 0.900 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.319406 ( -1.36607 2.21189 )
Epeak [keV] : 55.7178 ( -12.7618 -55.6928 )
Norm@50keV : 2.26986E-02 ( -0.0227505 0.383495 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 33.59 using 59 PHA bins.
# Reduced chi-squared = 0.5998 for 56 degrees of freedom
# Null hypothesis probability = 9.923956e-01
Photon flux (15-150 keV) in 1 sec: 0.518347 ( -0.11548 0.116352 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.42531e-08 ( -9.5165e-09 1.08691e-08 ) ergs/cm2
Time-resolved spectra
