TY  - JOUR
A1  - Rahmani, H.
A1  - Wendt, Martin
A1  - Srianand, R.
A1  - Noterdaeme, P.
A1  - Petitjean, P.
A1  - Molaro, P.
A1  - Whitmore, J. B.
A1  - Murphy, M. T.
A1  - Centurion, Martin
A1  - Fathivavsari, H.
A1  - D'Odorico, S.
A1  - Evans, T. M.
A1  - Levshakov, S. A.
A1  - Lopez, S.
A1  - Martins, C. J. A. P.
A1  - Reimers, D.
A1  - Vladilo, G.
T1  - The UVES large program for testing fundamental physics - II. Constraints on a change in mu towards quasar HE 0027-1836
T2  - Monthly notices of the Royal Astronomical Society
N2  - We present an accurate analysis of the H-2 absorption lines from the z(abs) similar to 2.4018 damped Ly alpha system towards HE 0027-1836 observed with the Very Large Telescope Ultraviolet and Visual Echelle Spectrograph (VLT/UVES) as a part of the European Southern Observatory Large Programme 'The UVES large programme for testing fundamental physics' to constrain the variation of proton-to-electron mass ratio, mu  m(p)/m(e). We perform cross-correlation analysis between 19 individual exposures taken over three years and the combined spectrum to check the wavelength calibration stability. We notice the presence of a possible wavelength-dependent velocity drift especially in the data taken in 2012. We use available asteroids spectra taken with UVES close to our observations to confirm and quantify this effect. We consider single-and two-component Voigt profiles to model the observed H-2 absorption profiles. We use both linear regression analysis and Voigt profile fitting where Delta mu/mu is explicitly considered as an additional fitting parameter. The two-component model is marginally favoured by the statistical indicators and we get Delta mu/mu = -2.5 +/- 8.1(stat) +/- 6.2(sys) ppm. When we apply the correction to the wavelength-dependent velocity drift, we find Delta mu/mu = -7.6 +/- 8.1(stat) +/- 6.3(sys) ppm. It will be important to check the extent to which the velocity drift we notice in this study is present in UVES data used for previous Delta mu/mu measurements.
KW  - intergalactic medium
KW  - quasars: absorption lines
KW  - quasars: individual: HE 0027-1836
Y1  - 2013
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/34682
SN  - 0035-8711
SN  - 1365-2966
VL  - 435
IS  - 1
SP  - 861
EP  - 878
PB  - Oxford Univ. Press
CY  - Oxford
ER  -