Andrew C. Collazzi, Bradley E. Schaefer, Adam Goldstein, Robert D. Preece
We consider the distribution of many samples of Gamma-Ray Bursts (GRBs) when
plotted in a diagram with their bolometric fluence (Sbolo) versus the observed
photon energy of peak spectral flux (Epeak,obs). In this diagram, bursts that
obey the Amati relation must lie above some limiting line, although
observational scatter is expected to be substantial. We confirm that early
bursts with spectroscopic redshifts are consistent with this limit. But, we
find that the bursts from BATSE, Swift, Suzaku, and Konus are all greatly in
violation of the limit. In the Sbolo-Epeak,obs diagram, we find that every
satellite has a greatly different distribution. This requires that selection
effects are dominating these distributions, which we identify. For detector
selections, the trigger threshold and the threshold to measure Epeak,obs
combine to make a diagonal cutoff with the position of this cutoff varying
greatly detector to detector. For selection effects due to the intrinsic
properties of the burst population, the distribution of Epeak,obs makes for
bursts with low and high values to be rare, while the fluence distribution
makes bright bursts uncommon. For a poor threshold, the combination of
selection effects serves to allow only bursts within a region along the limit
to be measured; these bursts will then appear to follow an Amati relation.
Therefore, the Amati relation is an artifact of selection effects within the
burst population and the detector. Therefore, the Amati relation should not be
used for cosmological tasks. This failure is in no way prejudicial against the
other luminosity relations.
View original:
http://arxiv.org/abs/1112.4347
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