Zobrazeno 1 - 10
of 37
pro vyhledávání: '"S. A. Levshakov"'
Autor:
S. A. Levshakov
Publikováno v:
GROUND-BASED ASTRONOMY IN RUSSIA. 21ST CENTURY. Proceedings of the All-Russian Conference.
Spacetime variations of physical constants can be associated with the existence of Higgs-like scalar field(s) that couple non-universally to the baryonic matter. Recent results of astronomical spectral measurements of the fractional changes in the el
Autor:
Xianming Chen, Simon Ellingsen, Y. Gong, S. A. Levshakov, Xindi Tang, Paola Castangia, Christian Henkel, A. Malawi, Benjamin Winkel, R. Mauersberger, T. P. McCarthy, H. Asiri, Silvia Leurini, P. K. Humire, Andrea Tarchi
Methanol (CH3OH) is one of the most abundant interstellar molecules, offering a vast number of transitions to be studied, including many maser lines. While the strongest Galactic CH3OH lines, the so-called class II masers, show no indications for the
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c28aca72d80e71966800e3755e094c35
http://hdl.handle.net/20.500.12386/31374
http://hdl.handle.net/20.500.12386/31374
Publikováno v:
Monthly Notices of the Royal Astronomical Society. 471:2143-2150
The offsets between the radial velocities of the rotational transitions of carbon monoxide and the fine structure transitions of neutral and singly ionized carbon are used to test the hypothetical variation of the fine structure constant, alpha. From
Autor:
S. A. Levshakov, M. G. Kozlov
Publikováno v:
Monthly Notices of the Royal Astronomical Society: Letters. 469:L16-L19
Star-forming galaxies at high redshifts are the ideal targets to probe the hypothetical variation of the fine-structure constant alpha over cosmological time scales. We propose a modification of the alkali doublets method which allows us to search fo
Autor:
R A Syunyaev, A V Ivanchik, D G Yakovlev, Robert A. Suris, Andrei Georgievich Zabrodskii, A D Kaminker, N N Rosanov, Andrei M. Bykov, Evgenii B. Aleksandrov, V K Khersonskii, Aleksandr Aleksandrovich Kaplyanskii, S A Levshakov
Publikováno v:
Physics-Uspekhi. 63:728-729
Autor:
Karl M. Menten, Carsten Henkel, A. V. Lapinov, M. Daprà, Wim Ubachs, S. A. Levshakov, Sebastien Muller, Hendrick L. Bethlem, Silvia Leurini
Publikováno v:
Monthly Notices of the Royal Astronomical Society
Monthly Notices of the Royal Astronomical Society, 472(4), 4434-4443. Oxford University Press
Dapra, M, Henkel, C, Levshakov, S A, Menten, K M, Muller, S, Bethlem, H L, Leurini, S, Lapinov, A V & Ubachs, W 2017, ' Testing the variability of the proton-to-electron mass ratio from observations of methanol in the dark cloud core L1498 ', Monthly Notices of the Royal Astronomical Society, vol. 472, no. 4, pp. 4434-4443 . https://doi.org/10.1093/mnras/stx2308
Monthly Notices of the Royal Astronomical Society, 472(4), 4434-4443. Oxford University Press
Dapra, M, Henkel, C, Levshakov, S A, Menten, K M, Muller, S, Bethlem, H L, Leurini, S, Lapinov, A V & Ubachs, W 2017, ' Testing the variability of the proton-to-electron mass ratio from observations of methanol in the dark cloud core L1498 ', Monthly Notices of the Royal Astronomical Society, vol. 472, no. 4, pp. 4434-4443 . https://doi.org/10.1093/mnras/stx2308
The dependence of the proton-to-electron mass ratio, mu, on the local matter density was investigated using methanol emission in the dense dark cloud core L1498. Towards two different positions in L1498, five methanol transitions were detected and an
Autor:
Giovanni Vladilo, Miriam Centurion, Sebastian Lopez, S. D'Odorico, Hadi Rahmani, Patrick Petitjean, Piercarlo Bonifacio, Dieter Reimers, Michael T. Murphy, S. A. Levshakov, Paolo Molaro, I. I. Agafonova, T. M. Evans, Raghunathan Srianand, J. Whitmore, Martin Wendt, Carlos Martins
Publikováno v:
Astronomische Nachrichten. 335:83-91
Absorption-line systems detected in high resolution quasar spectra can be used to compare the value of dimensionless fundamental constants such as the fine-structure constant, α, and the proton-to-electron mass ratio, μ = mp/me, as measured in remo
(Abridged) Aims. We derive the physical properties of a filament discovered in the dark cometary-shaped cloud L1251. Methods. Mapping observations in the NH3(1,1) and (2,2) inversion lines, encompassing 300 positions toward L1251, were performed with
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ec688303ebfa6d7c441a55d02203da3e
http://arxiv.org/abs/1601.00291
http://arxiv.org/abs/1601.00291
Publikováno v:
Astronomy & Astrophysics. 483:19-34
Aims. We reconstruct the spectral shape of the quasar ionizing radiation in the extreme-UV range (1 Ryd ≤ E 4R yd which is attributed to the He ii Lyman continuum opacity (τ He II c ∼ 1). A most likely source of this opacity is a quasar accretio
Publikováno v:
Astronomy & Astrophysics. 479:719-723
Aims. To obtain limits on the variation of the fine-structure constant alpha and the electron-to-proton mass ratio mu over different cosmological epochs. Methods. A new approach based on the comparison of redshifts of far infrared (FIR) fine-structur