Possible evidence for a variable fine-structure constant from QSO absorption lines: systematic errors
Abstract
Comparison of quasar (QSO) absorption spectra with laboratory spectra allows 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, α, may have been smaller in the past: [formmu2]Δα/α=(-0.72+/-0.18)×10-5 over the redshift range [formmu3]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 [formmu4]Δα/α from zero becomes more significant. We are led increasingly to the interpretation that α was slightly smaller in the past.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- November 2001
- DOI:
- 10.1046/j.1365-8711.2001.04841.x
- arXiv:
- arXiv:astro-ph/0012420
- Bibcode:
- 2001MNRAS.327.1223M
- Keywords:
-
- ATOMIC DATA;
- LINE: PROFILES;
- INSTRUMENTATION: SPECTROGRAPHS;
- METHODS: DATA ANALYSIS;
- TECHNIQUES: SPECTROSCOPIC;
- QUASARS: ABSORPTION LINES;
- Astrophysics
- E-Print:
- 15 pages, 8 figures, Accepted by MNRAS, small changes after referee's comments, accepted version