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 -15.888 sec. to 64.112 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.43475 ( -0.0300528 0.0301378 )
Norm@50keV : 5.87778E-02 ( -0.000995505 0.000994116 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 41.82 using 59 bins.
Reduced chi-squared = 0.733684
# Null hypothesis probability of 9.34e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 80 sec: 7.21670 ( -0.1462 0.14677 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.51315e-05 ( -7.30802e-07 7.30163e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -15.888 sec. to 64.112 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.32336 ( -0.0898119 0.124266 )
Epeak [keV] : 379.489 ( -166.024 -379.982 )
Norm@50keV : 6.52175E-02 ( -0.00661928 0.00782546 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 39.39 using 59 bins.
Reduced chi-squared = 0.703393
# Null hypothesis probability of 9.55e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 80 sec: 3.53302 ( -0.27854 0.41676 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.49614e-05 ( -7.54547e-07 7.5264e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 23.612 sec. to 24.612 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.74652 ( -0.103787 0.101919 )
Norm@50keV : 0.133576 ( -0.00833673 0.00829755 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 49.21 using 59 bins.
Reduced chi-squared = 0.863333
# Null hypothesis probability of 7.59e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 18.0394 ( -1.1323 1.1346 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.23299e-06 ( -7.9032e-08 7.93005e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 23.612 sec. to 24.612 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.3712 ( -0.403578 0.443034 )
Epeak [keV] : 85.6267 ( -22.9349 -85.6268 )
Norm@50keV : 0.205916 ( -0.0745458 0.133715 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 46.72 using 59 bins.
Reduced chi-squared = 0.834286
# Null hypothesis probability of 8.07e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 17.7512 ( -1.1717 1.1748 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.21143e-06 ( -8.35575e-08 8.32129e-08 ) ergs/cm2
Time-resolved spectra
