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Title:Search For A Variation Of The Proton-electron Mass Ratio From Methanol Observations
Author(s):Ubachs, Wim
Contributor(s):Menten, Karl; Henkel, Christian; Muller, Sebastien; Kanekar, Nissim; Bethlem, Hendrick; Dapra, Mario; Bagdonaite, Julija
Abstract:A limit on a possible cosmological variation of the proton-to-electron mass ratio $\mu$ is derived from observation of methanol lines in the PKS1830-211 lensed galaxy at redshift $z \sim 0.89$ with the Effelsberg 100 m single-dish radio telescope (at frequencies 6.5 - 32 GHz), the IRAM 30 m telescope (at frequencies 80 - 160 GHz), and band-6 of the novel ALMA telescope array (at 260 GHz). Ten different absorption lines of CH$_3$OH are detected covering a wide range of sensitivity coefficients $K_{\mu}$. Systematic effects of chemical segregation, excitation temperature, frequency dependence, and time variability of the back- ground source are quantified. A robust constraint of $\Delta\mu/\mu = (1.0 \pm 0.8_{stat} \pm 1.0_{syst}) \times 10^{-7}$ is derived from this large sample of lines belonging to a single molecular species. Analysis of additional observations at the E-VLA radio telescope is under way.
Issue Date:2014-06-19
Publisher:International Symposium on Molecular Spectroscopy
Citation Info:Ubachs, W.; Menten, K.; Henkel, C.; Muller, S.; Kanekar, N.; Bethlem, H.; Dapra, M.; Bagdonaite, J. SEARCH FOR A VARIATION OF THE PROTON-ELECTRON MASS RATIO FROM METHANOL OBSERVATIONS. Proceedings of the International Symposium on Molecular Spectroscopy, Urbana, IL, June 16-21, 2014. DOI: 10.15278/isms.2014.RH14
Genre:Conference Paper / Presentation
Rights Information:Copyright 2014 by the authors. Licensed under a Creative Commons Attribution 4.0 International License.
Date Available in IDEALS:2014-09-17

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