| Autor: |
J, Bagdonaite, M, Daprà, P, Jansen, H L, Bethlem, W, Ubachs, S, Muller, C, Henkel, K M, Menten |
| Rok vydání: |
2013 |
| Zdroj: |
Physical review letters. 111(23) |
| ISSN: |
1079-7114 |
| Popis: |
A limit on a possible cosmological variation of the proton-to-electron mass ratio μ is derived from methanol (CH3OH) absorption lines in the benchmark PKS1830-211 lensing galaxy at redshift z=0.89 observed with the Effelsberg 100-m radio telescope, the Institute de Radio Astronomie Millimétrique 30-m telescope, and the Atacama Large Millimeter/submillimeter Array. Ten different absorption lines of CH3OH covering a wide range of sensitivity coefficients K(μ) are used to derive a purely statistical 1σ constraint of Δμ/μ=(1.5±1.5)×10(-7) for a lookback time of 7.5 billion years. Systematic effects of chemical segregation, excitation temperature, frequency dependence, and time variability of the background source are quantified. A multidimensional linear regression analysis leads to a robust constraint of Δμ/μ=(-1.0±0.8(stat)±1.0(sys))×10(-7). |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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