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The methanol molecule CH3OH has a complex microwave spectrum with a large number of very strong lines. This spectrum includes purely rotational transitions as well as transitions with contributions of the internal degree of freedom…

宇宙学与河外天体物理 · 物理学 2013-06-12 S. A. Levshakov , M. G. Kozlov , D. Reimers

Full-dimensional (12D) vibrational states of the methanol molecule (CH$_3$OH) have been computed using the GENIUSH-Smolyak approach and the potential energy surface from Qu and Bowman (2013). All vibrational energies are converged better…

化学物理 · 物理学 2024-09-05 Ayaki Sunaga , Gustavo Avila , Edit Matyus

Recently, methanol was identified as a sensitive target system to probe variations of the proton-to-electron mass ratio $\mu$ [Jansen \emph{et al.} Phys. Rev. Lett. \textbf{106}, 100801 (2011)]. The high sensitivity of methanol originates…

化学物理 · 物理学 2012-03-07 Paul Jansen , Isabelle Kleiner , Li-Hong Xu , Wim Ubachs , Hendrick L. Bethlem

We report on the using of torsion-rotational transitions in the CH3OH and (13)CH3OH molecules to evaluate possible variations of the physical constant mu=m_e/m_p - the electron-to-proton mass ratio - from spectral observations of emission…

星系天体物理 · 物理学 2024-05-09 J. S. Vorotyntseva , S. A. Levshakov

Torsion-rotation transitions in molecules exhibiting hindered internal rotation possess enhanced sensitivities to a variation of the proton-to-electron mass ratio. This enhancement occurs due to a cancellation of energies associated with…

原子物理 · 物理学 2013-06-06 Paul Jansen , Li-Hong Xu , Isabelle Kleiner , Hendrick L. Bethlem , Wim Ubachs

Methanol is observed in a wide range of astrophysical sources throughout the universe, and comprehensive databases of the millimeter and THz spectra of CH3OH and its principal isotopologues represent important tools for the astronomical…

天体物理仪器与方法 · 物理学 2015-06-22 Li-Hong Xu , R. M. Lees , Yun Hao , H. S. P. Mueller , C. P. Endres , F. Lewen , S. Schlemmer , K. M. Menten

Numerical calculations of the sensitivity coefficients, Q_mu, of microwave molecular transitions in the ground torsion-rotation state of deuterated methanol (CH3OD, CD3OH, and CD3OD) to small variations in the fundamental physical constant…

高能物理 - 唯象学 · 物理学 2024-06-18 J. S. Vorotyntseva , S. A. Levshakov , M. G. Kozlov

We present results on simultaneous observations of Class~I methanol masers at 25, 36, and 44 GHz towards 22 Galactic targets carried out with the Effelsberg 100-m telescope. The study investigates relations between the hyperfine (HF)…

Methanol is an abundant molecule in space. The column density of CH$_3^{18}$OH is in some star-forming regions so high that the search for CH$_3^{17}$OH is promising. But only very few transition frequencies of CH$_3^{17}$OH with a…

星系天体物理 · 物理学 2024-08-28 Holger S. P. Müller , Vadim V. Ilyushin , Arnaud Belloche , Frank Lewen , Stephan Schlemmer

Deuterium fractionation is highly efficient during the early stages of star formation, particularly in starless and prestellar cores where temperatures are low (<10 K) and molecular freeze-out onto dust grains is significant. Methanol forms…

We report the first detection of triply-deuterated methanol, with 12 observed transitions, towards the low-mass protostar IRAS 16293-2422, as well as multifrequency observations of 13CH3OH, used to derive the column density of the main…

天体物理学 · 物理学 2007-05-23 B. Parise , A. Castets , E. Herbst , E. Caux , C. Ceccarelli , I. Mukhopadhyay , A. G. G. M. Tielens

We have started a measurement campaign of numerous methanol isotopologs in low-lying torsional states in order to provide extensive line lists for radio astronomical observations from an adequate spectroscopic model and to investigate how…

Observations of Serpens have been performed at the JCMT using Harp-B. Maps over a 4.5'x5.4' region were made in a frequency window around 338 GHz, covering the 7-6 transitions of methanol. Emission is extended over each source, following…

太阳与恒星天体物理 · 物理学 2015-05-18 L. E. Kristensen , E. F. van Dishoeck , T. A. van Kempen , H. M. Cuppen , C. Brinch , J. K. Jørgensen , M. R. Hogerheijde

Deuterated molecules have been detected and studied toward Orion BN/KL in the past decades, mostly with single-dish telescopes. However, high angular resolution data are critical not only for interpreting the spatial distribution of the…

星系天体物理 · 物理学 2015-06-05 T. -C. Peng , D. Despois , N. Brouillet , B. Parise , A. Baudry

The abundance of deuterated molecules in a star-forming region is sensitive to the environment in which they are formed. Deuteration fractions therefore provide a powerful tool for studying the physical and chemical evolution of a…

Observations of the frequencies of different rotational transitions of the methanol molecule have provided the most sensitive probe to date for changes in the proton-to-electron mass ratio, over space and time. Using methanol absorption…

星系天体物理 · 物理学 2017-01-25 M. A. Marshall , S. P. Ellingsen , J. E. J. Lovell , J. M. Dickey , M. A. Voronkov , S. L. Breen

Using the Haystack Observatory 37-m radio telescope we have undertaken a search for emission in the 2(0)-3(1)E rotational transition of methanol in its first torsionally excited state (v_t=1) at 44.9 GHz. We examined seven galactic sources…

天体物理学 · 物理学 2009-11-07 M. A. Voronkov , M. C. Austin , A. M. Sobolev

Methanol (CH$_{3}$OH) is a key complex organic molecule (COM) in the interstellar medium, widely used as a tracer of dense gas and hot molecular cores (HMCs). Using high-resolution ALMA observations from the ATOMS survey, we investigate the…

The deuteration of molecules forming in the ices such as methanol (CH$_3$OH) is sensitive to the physical conditions during their formation in dense cold clouds and can be probed through observations of deuterated methanol in hot cores.…

The possibility of using astrophysical observations of rotational transitions in the methanol molecule to measure, or constrain temporal and spatial variations in the proton-to-electron mass ratio (mu) has recently been investigated by…

宇宙学与河外天体物理 · 物理学 2015-06-03 Simon Ellingsen , Maxim Voronkov , Shari Breen
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