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 -0.708 sec. to 4.520 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.16502 ( -0.0566231 0.0568583 )
Norm@50keV : 3.69589E-02 ( -0.00121655 0.00121589 )
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#Fit statistic : Chi-Squared = 61.05 using 59 PHA bins.
# Reduced chi-squared = 1.071 for 57 degrees of freedom
# Null hypothesis probability = 3.324200e-01
Photon flux (15-150 keV) in 5.228 sec: 4.31808 ( -0.14908 0.14929 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.98041e-06 ( -6.91278e-08 6.92642e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.708 sec. to 4.520 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.736291 ( -0.229043 0.241283 )
Epeak [keV] : 172.191 ( -41.4013 123.31 )
Norm@50keV : 5.69841E-02 ( -0.0114748 0.01513 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.40 using 59 PHA bins.
# Reduced chi-squared = 0.8999 for 56 degrees of freedom
# Null hypothesis probability = 6.860696e-01
Photon flux (15-150 keV) in 5.228 sec: 4.23469 ( -0.15472 0.15498 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.95e-06 ( -7.20889e-08 7.19253e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.104 sec. to 1.104 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.06319 ( -0.0637516 0.0640873 )
Norm@50keV : 9.51735E-02 ( -0.00371251 0.00371072 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 67.92 using 59 PHA bins.
# Reduced chi-squared = 1.192 for 57 degrees of freedom
# Null hypothesis probability = 1.524917e-01
Photon flux (15-150 keV) in 1 sec: 0.574127 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 1.00716e-06 ( -4.24428e-08 4.25274e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.104 sec. to 1.104 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.494233 ( -0.260856 0.277031 )
Epeak [keV] : 153.042 ( -32.0216 77.7389 )
Norm@50keV : 0.171046 ( -0.039247 0.0541617 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.07 using 59 PHA bins.
# Reduced chi-squared = 0.9477 for 56 degrees of freedom
# Null hypothesis probability = 5.864264e-01
Photon flux (15-150 keV) in 1 sec: 10.8263 ( -0.4458 0.4461 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.61102e-07 ( -3.43718e-08 2.76537e-08 ) ergs/cm2
Time-resolved spectra
