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Precise limits on cosmological variability of the fine-structure constant with zinc and chromium quasar absorption lines
- Source :
- Monthly Notices of the Royal Astronomical Society. 461:2461-2479
- Publication Year :
- 2016
- Publisher :
- Oxford University Press (OUP), 2016.
-
Abstract
- The strongest transitions of Zn and CrII are the most sensitive to relative variations in the fine-structure constant ($\Delta\alpha/\alpha$) among the transitions commonly observed in quasar absorption spectra. They also lie within just 40\AA\ of each other (rest frame), so they are resistant to the main systematic error affecting most previous measurements of $\Delta\alpha/\alpha$: long-range distortions of the wavelength calibration. While Zn and CrII absorption is normally very weak in quasar spectra, we obtained high signal-to-noise, high-resolution echelle spectra from the Keck and Very Large Telescopes of 9 rare systems where it is strong enough to constrain $\Delta\alpha/\alpha$ from these species alone. These provide 12 independent measurements (3 quasars were observed with both telescopes) at redshifts 1.0--2.4, 11 of which pass stringent reliability criteria. These 11 are all consistent with $\Delta\alpha/\alpha=0$ within their individual uncertainties of 3.5--13 parts per million (ppm), with a weighted mean $\Delta\alpha/\alpha = 1.2\pm1.7_{\rm stat}\pm0.9_{\rm sys}$ ppm (1$\sigma$ statistical and systematic uncertainties), indicating no significant cosmological variations in $\alpha$. This is the first statistical sample of absorbers that is resistant to long-range calibration distortions (at the $<br />Comment: 20 pages, 15 figures. Accepted by MNRAS. Quasar spectra and Zn/CrII absorption profile fits are available at http://dx.doi.org/10.5281/zenodo.51504 . v2: Erratum added (in press at MNRAS), with numerical results and figures updated accordingly; no substantial changes nor any change to conclusions
- Subjects :
- High Energy Physics - Theory
Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Absorption spectroscopy
Atomic Physics (physics.atom-ph)
Extinction (astronomy)
FOS: Physical sciences
Astrophysics::Cosmology and Extragalactic Astrophysics
General Relativity and Quantum Cosmology (gr-qc)
Astrophysics
01 natural sciences
General Relativity and Quantum Cosmology
Spectral line
Physics - Atomic Physics
High Energy Physics - Phenomenology (hep-ph)
0103 physical sciences
Absorption (logic)
010306 general physics
010303 astronomy & astrophysics
Physics
Astronomy and Astrophysics
Fine-structure constant
Quasar
Rest frame
Redshift
High Energy Physics - Phenomenology
High Energy Physics - Theory (hep-th)
Space and Planetary Science
Astrophysics - Cosmology and Nongalactic Astrophysics
Subjects
Details
- ISSN :
- 13652966 and 00358711
- Volume :
- 461
- Database :
- OpenAIRE
- Journal :
- Monthly Notices of the Royal Astronomical Society
- Accession number :
- edsair.doi.dedup.....a608da28d3700a107d26d232779ba4e7