Most precise single redshift bound to
Most precise single redshift bound to the variability
of the fine-structure constant
S. A. Levshakov1,
M. Centurión2,
P. Molaro2,
S. D'Odorico3,
D. Reimers4,
R. Quast4, and
M. Pollmann4
1Department of Theoretical Astrophysics,
Ioffe Physico-Technical Institute, 194021 St. Petersburg, Russia
2Osservatorio Astronomico di Trieste,
Via G. B. Tiepolo 11,
34131 Trieste, Italy
3European Southern Observatory, Karl-Schwarzschild-Strasse 2,
D-85748 Garching bei München, Germany
4Hamburger Sternwarte, Universität Hamburg,
Gojenbergsweg 112, D-21029 Hamburg, Germany
Verification of
theoretical predictions of an oscillating behavior of the
fine-structure constant, a,
with cosmic time requires high precision measurements at
individual redshifts, while in earlier studies the mean
Da/a values
averaged over wide redshift intervals were usually reported.
This requirement can be met via
the single ion differential a measurement (SIDAM) procedure.
We apply the SIDAM to the FeII lines
associated with the damped Lya
system observed at z = 1.15 in the spectrum of HE 0515-4414.
The weighted mean
áDa/añ
calculated on base of carefully selected
33 FeII pairs is (0.10±0.77)×10-6 (1s C.L.).
The obtained result represents the absolute improvement with
respect to what has been done in the measurements of
Da/a.
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On 20 Oct 2005, 17:41.