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A new measure of Delta alpha/alpha at redshift z = 1.84 from very high resolution spectra of Q1101-264

S. A. Levshakov·P. Molaro·S. Lopez·S. D'Odorico·M. Centurion·P. Bonifacio·I. I. Agafonova·D. Reimers
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Abstract

We probe the evolution of the fine-structure constant, alpha, with cosmic time. Accurate positions of the FeII lines 1608, 2382,and 2600 A are measured in the z = 1.84 absorption system from a high-resolution (FWHM = 3.8 km/s) and high signal-to-noise (S/N >= 100) spectrum of the quasar Q1101-264 (z_em = 2.15, V = 16.0), integrated for 15.4 hours. The Single Ion Differential alpha Measurement (SIDAM) procedure and the Delta chi^2 method are used to set constraints on Delta alpha/alpha. We have found a relative radial velocity shift between the 1608 A and 2382,2600 A lines of Delta v = -180 +/- 85 m/s (both random and systematic errors are included), which, if real, would correspond to Delta alpha/alpha = (5.4 +/- 2.5) 10^{-6} (1sigma C.L.). Considering the strong implications of a such variability, additional observations with comparable accuracy at redshift z ~ 1.8 are required to confirm this result.

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S. A. Levshakov, P. Molaro, S. Lopez, S. D'Odorico, M. Centurion, P. Bonifacio, I. I. Agafonova, D. Reimers. 2007-03-02. A new measure of Delta alpha/alpha at redshift z = 1.84 from very high resolution spectra of Q1101-264. https://doi.org/10.1051/0004-6361%3A20066064

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