A&A 466, 1077-1082 (2007)
A new measure of at redshift from very high resolution spectra of Q 1101-264S. A. Levshakov1, P. Molaro2, 3, S. Lopez4, S. D'Odorico5, M. Centurión2, P. Bonifacio2, 3, I. I. Agafonova1, and D. Reimers1
1 Hamburger Sternwarte, Universität Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany
2 Osservatorio Astronomico di Trieste, via G. B. Tiepolo 11, 34131 Trieste, Italy
3 Observatoire de Paris, 61 avenue de l'Observatoire, 75014 Paris, France
4 Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago, Chile
5 European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching bei München, Germany
(Received 19 July 2006 / Accepted 26 February 2007)
Aims.We probe the evolution of the fine-structure constant with cosmic time.
Methods.Accurate positions of the lines , , and are measured in the = 1.84 absorption system from a high-resolution (FWHM ~ 3.8 km s-1) and high signal-to-noise (S/N 100) spectrum of the quasar Q 1101-264 ( = 2.15, V = 16.0), integrated for 15.4 h. The Single Ion Differential Measurement (SIDAM) procedure and the method are used to set constraints on .
Results.We have found a relative radial velocity shift between the and lines of 85 m s-1 (both random and systematic errors are included), which, if real, would correspond to = 10-6 ( C.L.). Considering the strong implications of a such variability, additional observations with comparable accuracy at redshift are required to confirm this result.
Key words: cosmology: observations -- line: profiles -- galaxies: quasars: absorption lines -- galaxies: quasars: individual: Q 1101-264
© ESO 2007