35930
2012
2012
eng
8
3
541
article
EDP Sciences
Les Ulis
1
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QSO 0347-383 and the invariance of m(p)/m(e) in the course of cosmic time
Context. The variation of the dimensionless fundamental physical constant mu = m(p)/m(e) - the proton to electron mass ratio - can be constrained via observation of Lyman and Werner lines of molecular hydrogen in the spectra of damped Lyman alpha systems (DLAs) in the line of sight to distant QSOs.
Aims. Our intention is to maximize the possible precision of quasar absorption spectroscopy with regard to the investigation of the variation of the proton-to-electron mass-ratio mu. The demand for precision requires an understanding of the errors involved and effective techniques to handle present systematic errors.
Methods. An analysis based on UVES high resolution data sets of QSO 0347-383 and its DLA is put forward and new approaches to some of the steps involved in the data analysis are introduced. We apply corrections for the observed offsets between discrete spectra and for the first time we find indications for inter-order distortions.
Results. Drawing on VLT-UVES observations of QSO 0347-383 in 2009 our analysis yields Delta mu/mu = (4.3 +/- 7.2) x 10(-6) at z(abs) = 3.025.
Conclusions. Current analyzes tend to underestimate the impact of systematic errors. Based on the scatter of the measured redshifts and the corresponding low significance of the redshift-sensitivity correlation we estimate the limit of accuracy of line position measurements to similar to 220 m s (1), consisting of roughly 150 m s (1) due to the uncertainty of the absorption line fit and about 150 m s (1) allocated to systematics related to instrumentation and calibration.
Astronomy and astrophysics : an international weekly journal
10.1051/0004-6361/201218862
0004-6361
wos:2011-2013
A69
WOS:000304390900069
Wendt, M (reprint author), Univ Potsdam, Inst Phys & Astron, D-14476 Golm, Germany., mwendt@astro.physik.uni-potsdam.de
ESO Paranal Observatory [083.A.0733]
Martin Wendt
P. Molaro
eng
uncontrolled
cosmology: observations
eng
uncontrolled
quasars: absorption lines
eng
uncontrolled
quasars: individual: QSO 0347-383
eng
uncontrolled
early Universe
Institut für Physik und Astronomie
Referiert
38327
2014
2014
eng
106
112
7
1
335
article
Wiley-VCH
Weinheim
1
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Constraints on variations of m(p)/m(e) based on UVES observations of H-2
This article summarizes the latest results on the proton-to-electron mass ratio derived from H-2 observations at high redshift in the light of possible variations of fundamental physical constants. The focus lies on UVES observations of the past years as enormous progress was achieved since the first positive results on / were published. With the better understanding of systematics, dedicated observation runs, and numerous approaches to improve wavelength calibration accuracy, all current findings are in reasonable good agreement with no variation and provide an upper limit of / < 1 x 10(-5) for the redshift range of 2 < z < 3. ((
Astronomische Nachrichten = Astronomical notes
10.1002/asna.201312008
0004-6337
1521-3994
wos:2014
WOS:000330636200016
Wendt, M (reprint author), Univ Potsdam, Inst Phys & Astron, D-14476 Potsdam, Germany., mwendt@astro.physik.uni-potsdam.de
Martin Wendt
eng
uncontrolled
cosmology: observations
eng
uncontrolled
early Universe
eng
uncontrolled
quasars: absorption lines
Institut für Physik und Astronomie
Referiert