Possible evidence for a variable fine structure constant from QSO absorption lines: systematic errors
Abstract
Comparison of quasar absorption spectra with laboratory spectra allow us to probe possible variations in the fundamental constants over cosmological time-scales. In a companion paper we present an analysis of Keck/HIRES spectra and report possible evidence suggesting that the fine structure constant, alpha, may have been smaller in the past: da/a = (-0.72 +/- 0.18) * 10^{-5} over the redshift range 0.5 < z < 3.5. In this paper we describe a comprehensive investigation into possible systematic effects. Most of these do not significantly influence our results. When we correct for those which do produce a significant systematic effect in the data, the deviation of da/a from zero becomes more significant. We are lead increasingly to the interpretation that alpha was slightly smaller in the past.
Cite
@article{arxiv.astro-ph/0012420,
title = {Possible evidence for a variable fine structure constant from QSO absorption lines: systematic errors},
author = {M. T. Murphy and J. K. Webb and V. V. Flambaum and C. W. Churchill and J. X. Prochaska},
journal= {arXiv preprint arXiv:astro-ph/0012420},
year = {2009}
}
Comments
15 pages, 8 figures, Accepted by MNRAS, small changes after referee's comments, accepted version