Volume 466, Number 3, May II 2007
|Page(s)||1077 - 1082|
|Section||Stellar structure and evolution|
|Published online||24 April 2007|
A new measure of at redshift from very high resolution spectra of Q 1101–264*
Hamburger Sternwarte, Universität Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany e-mail: firstname.lastname@example.org
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
Accepted: 26 February 2007
Aims.We probe the evolution of the fine-structure constant α with cosmic time.
Methods.Accurate positions of the lines , , and are measured in the zabs = 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 (zem = 2.15, ), integrated for 15.4 h. The Single Ion Differential α 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
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