Further constraints on variation of the fine-structure constant from alkali-doublet QSO absorption lines
Abstract
Comparison of quasar (QSO) absorption-line spectra with laboratory spectra provides a precise probe for variability of the fine-structure constant, α, over cosmological time-scales. We constrain variation in α in 21 Keck/HIRES Siiv absorption systems using the alkali-doublet (AD) method in which changes in α are related to changes in the doublet spacing. The precision obtained with the AD method has been increased by a factor of 3: Δα/α=(-0.5+/-1.3)×10-5. We also analyse potential systematic errors in this result. Finally, we compare the AD method with the many-multiplet method, which has achieved an order of magnitude greater precision, and we discuss the future of the AD method.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- November 2001
- DOI:
- 10.1046/j.1365-8711.2001.04842.x
- arXiv:
- arXiv:astro-ph/0012421
- Bibcode:
- 2001MNRAS.327.1237M
- Keywords:
-
- ATOMIC DATA;
- LINE: PROFILES;
- TECHNIQUES: SPECTROSCOPIC;
- QUASARS: ABSORPTION LINES;
- ULTRAVIOLET: GENERAL;
- Astrophysics
- E-Print:
- 8 pages, 3 figures, Accepted by MNRAS, small changes after referee's comments, accepted version