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 -2.252 sec. to 24.492 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.69125 ( -0.27396 0.260047 )
Norm@50keV : 1.86039E-03 ( -0.000318406 0.000310013 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 43.53 using 59 bins.
Reduced chi-squared = 0.763684
# Null hypothesis probability of 9.05e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 26.74 sec: 0.246340 ( -0.036356 0.036363 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.6099e-07 ( -8.18656e-08 8.39663e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -2.252 sec. to 24.492 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.25654 ( -0.761451 1.29018 )
Epeak [keV] : 76.7188 ( -54.4419 -76.7188 )
Norm@50keV : 3.23539E-03 ( -0.00323539 0.0137951 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 43.01 using 59 bins.
Reduced chi-squared = 0.768036
# Null hypothesis probability of 8.99e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 26.74 sec: 0.242321 ( -0.037623 0.037526 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.41255e-07 ( -9.27966e-08 9.48513e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 10.624 sec. to 11.624 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.01489 ( -0.697753 0.54831 )
Norm@50keV : 3.87879E-03 ( -0.00175077 0.0016511 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 57.98 using 59 bins.
Reduced chi-squared = 1.01719
# Null hypothesis probability of 4.39e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 0.585885 ( -0.189457 0.189584 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.58088e-08 ( -1.41856e-08 1.53335e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 10.624 sec. to 11.624 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.688297 ( -2.96243 -0.739872 )
Epeak [keV] : 40.4502 ( -40.4248 -40.4248 )
Norm@50keV : 0.145444 ( -0.174985 45727.6 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 56.06 using 59 bins.
Reduced chi-squared = 1.00107
# Null hypothesis probability of 4.73e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 0.548718 ( -0.199061 0.19465 ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Time-resolved spectra
