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 -2.720 sec. to 14.596 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.13577 ( -0.216718 0.202319 )
Norm@50keV : 6.08207E-03 ( -0.000877248 0.000855618 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 75.86 using 59 bins.
Reduced chi-squared = 1.33088
# Null hypothesis probability of 4.82e-02 with 57 degrees of freedom
Photon flux (15-150 keV) in 17.32 sec: 0.974201 ( -0.107926 0.107999 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.82602e-07 ( -1.25311e-07 1.27462e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -2.720 sec. to 14.596 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.23766 ( -0.7147 1.29545 )
Epeak [keV] : 34.6986 ( -30.2825 13.673 )
Norm@50keV : 2.03189E-02 ( -0.0203321 0.099852 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 73.36 using 59 bins.
Reduced chi-squared = 1.31
# Null hypothesis probability of 5.97e-02 with 56 degrees of freedom
Photon flux (15-150 keV) in 17.32 sec: 0.943504 ( -0.113412 0.112946 ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 1.140 sec. to 2.140 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.82624 ( -0.424705 0.387163 )
Norm@50keV : 1.35457E-02 ( -0.00361252 0.00347684 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 49.64 using 59 bins.
Reduced chi-squared = 0.870877
# Null hypothesis probability of 7.45e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 1.88600 ( -0.44534 0.44601 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.24626e-07 ( -3.26171e-08 3.32187e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.140 sec. to 2.140 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.3669 ( -0.858121 1.95229 )
Epeak [keV] : 65.0526 ( -54.3238 -65.0527 )
Norm@50keV : 2.39278E-02 ( -0.0239279 0.249586 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 49.33 using 59 bins.
Reduced chi-squared = 0.880893
# Null hypothesis probability of 7.24e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 1.86449 ( -0.45187 0.45111 ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Time-resolved spectra
