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The understanding of organic content of protoplanetary discs is one of the main goals of the planet formation studies. As an attempt to guide the observational searches for weak lines of complex species in discs, we modelled the…

太阳与恒星天体物理 · 物理学 2016-05-13 S. Yu. Parfenov , D. A. Semenov , A. M. Sobolev , M. D. Gray

We report Westerbork Synthesis Radio Telescope and Arecibo Telescope observations of the redshifted satellite OH-18cm lines at $z \sim 0.247$ towards PKS1413+135. The "conjugate" nature of these lines, with one line in emission and the…

宇宙学与河外天体物理 · 物理学 2015-05-18 Nissim Kanekar , Jayaram N. Chengalur , Tapasi Ghosh

Far infrared fine-structure transitions of CI and CII and rotational transitions of CO are used to probe hypothetical variations of the electron-to-proton mass ratio mu = m_e/m_p at the epoch of reionization (z > 6). A constraint on Delta…

宇宙学与河外天体物理 · 物理学 2020-09-09 S. A. Levshakov , M. G. Kozlov , I. I. Agafonova

We report on new tests that improve our previous (2009-2010) estimates of the electron-to-proton mass ratio variation, mu = m_e/m_p. Subsequent observations (2011-2013) at the Effelsberg 100-m telescope of a sample of eight molecular cores…

宇宙学与河外天体物理 · 物理学 2013-10-02 S. A. Levshakov , C. Henkel , D. Reimers , P. Molaro

Ethylene glycol in its ground conformation has tunneling transition with the frequency about 7 GHz. This leads to a rather complicated tunneling-rotational spectrum. Because tunneling and rotational energies have different dependence on the…

原子物理 · 物理学 2015-06-18 A. V. Viatkina , M. G. Kozlov

The variation of the dimensionless fundamental physical constant mu=m_p/m_e can be checked through observation of Lyman and Werner lines of molecular hydrogen in the spectra of distant QSOs. Our intention is to asses the accuracy of the…

宇宙学与河外天体物理 · 物理学 2016-02-03 Martin Wendt , Paolo Molaro

Observations of H2 spectra in the line-of-sight of distant quasars may reveal a variation of the proton-electron mass ratio mu=m_p/m_e at high redshift, typically for z>2. Currently four high-quality systems (Q0347-383, Q0405-443, Q0528-250…

宇宙学与河外天体物理 · 物理学 2015-05-27 Wim Ubachs , Julija Bagdonaite , Michael T. Murphy , Ruth Buning , Lex Kaper

The ALMA interferometer, with its unprecedented combination of high-sensitivity and high-angular resolution, allows for (sub-)mm wavelength mapping of protostellar systems at Solar System scales. Astrochemistry has benefited from imaging…

We report on a large 44 GHz ($7_0-6_1$ A$^+$) methanol (CH$_3$OH) maser survey of the Galactic Center (GC). The Karl G. Jansky Very Large Array was used to search for CH$_3$OH maser emission covering a large fraction of the region around…

太阳与恒星天体物理 · 物理学 2016-12-07 Bridget McEwen , Loránt Sjouwerman , Ylva Pihlström

We report on the interferometric detection of 36.2 GHz Class I methanol emission with the new 27-40 GHz Ka band receivers available on the Expanded Very Large Array (EVLA). The brightness temperatures of the interferometric 36 GHz…

星系天体物理 · 物理学 2015-05-18 Lorant O. Sjouwerman , Ylva M. Pihlstrom , Vincent L. Fish

We present an absorption-line survey of optically thick gas clouds -- Lyman Limit Systems (LLSs) -- observed at high dispersion with spectrometers on the Keck and Magellan telescopes. We measure column densities of neutral hydrogen NHI and…

宇宙学与河外天体物理 · 物理学 2015-10-14 J. Xavier Prochaska , John M. O'Meara , Michele Fumagalli , Rebecca A. Bernstein , Scott M. Burles

Methanol is a seed species of complex organic molecules that is of fundamental importance in astrochemistry. Although various isotopologues of CH$_3$OH have been detected in the interstellar medium (ISM), CH$_{3}$$^{17}$OH is only…

星系天体物理 · 物理学 2025-10-10 Yoshimasa Watanabe , Takahiro Oyama , Akemi Tamanai , Shaoshan Zeng , Nami Sakai

We present the first astrophysical detection of methanol (CH3OH) in the torsional band near 25 um. Using high resolution mid-infrared (MIR) spectroscopy, we identified over seventy gas-phase CH3OH absorption lines between 20 and 28 um…

Maser lines from different molecular species, including water, hydroxyl, and methanol, are common observational phenomena associated with massive star forming regions. In particular, the methanol maser appears as an ideal tool to study the…

星系天体物理 · 物理学 2014-06-04 L. Olmi , E. D. Araya , P. Hofner , S. Molinari , J. Morales Ortiz , L. Moscadelli , M. Pestalozzi

We report accurate laboratory measurements of selected methanol transition frequencies between 0.834 and 230 GHz in order to facilitate astronomical velocity analyses. New data have been obtained between 10 and 27 GHz and between 60 and 119…

天体物理学 · 物理学 2011-03-02 H. S. P. Mueller , K. M. Menten , H. Maeder

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 have examined methanol emission from Orion KL with of the {\em Herschel}/HIFI instrument, and detected two methanol bands centered at 524 GHz and 1061 GHz. The 524 GHz methanol band (observed in HIFI band 1a) is dominated by the isolated…

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.…

Discovery of periodic maser emission was an unexpected result from monitoring observations of methanol transitions in high-mass young stellar objects. We report on the detection of five new periodic sources from a monitoring program with…

太阳与恒星天体物理 · 物理学 2020-01-08 Mateusz Olech , Marian Szymczak , Paweł Wolak , Rafał Sarniak , Anna Bartkiewicz

Absorption lines of H$_2$ and HD molecules observed at high redshift in the line of sight towards quasars are a test ground to search for variation of the proton-to-electron mass ratio $\mu$. For this purpose, results from astronomical…

宇宙学与河外天体物理 · 物理学 2019-02-13 W. Ubachs , E. J. Salumbides , M. T. Murphy , H. Abgrall , E. Roueff