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An Australia Telescope Compact Array search for 22 GHz water masers towards 6.7 GHz class II methanol masers detected in the Methanol Multibeam (MMB) survey has resulted in the detection of extremely high velocity emission from one of the…

Astrophysics of Galaxies · Physics 2015-06-16 A. M. Titmarsh , S. P. Ellingsen , S. L. Breen , J. L. Caswell , M. A. Voronkov

We report the results of our systematic survey for Galactic 6.7 GHz Class II CH$_3$OH maser emission toward a sample of young stellar objects. The survey was conducted with the Shanghai Tianma Radio Telescope (TMRT). The sample consists of…

Astrophysics of Galaxies · Physics 2019-06-14 Kai Yang , Xi Chen , Zhi-Qiang Shen , Xiao-Qiong Li , Jun-Zhi Wang , Dong-Rong Jiang , Juan Li , Jian Dong , Ya-Jun Wu , Hai-Hua Qiao

Context: Class II methanol masers at 6.7 GHz originate close to high-mass young stellar objects (HMYSOs). Their high sensitivity to local condition variations makes them a useful marker of the activity of the emerging massive stars. Aims:…

Astrophysics of Galaxies · Physics 2022-07-27 M. Durjasz , M. Szymczak , M. Olech , A. Bartkiewicz

The effect of quasi-resonance energy transfer in collisions between H$_2$ and H$_2$O molecules in H$_2$O maser sources is investigated. New data on the state-to-state rate coefficients for collisional transitions for H$_2$O and H$_2$…

High Energy Astrophysical Phenomena · Physics 2014-07-14 A. V. Nesterenok , D. A. Varshalovich

Context: NGC7538 is known to host a 6.7 and 12.2GHz methanol maser cospatial with a Ultra Compact (UC) HII region, IRS1. Aims: We report on the serendipitous discovery of two additional 6.7GHz methanol masers in the same region, not…

Astrophysics · Physics 2007-05-23 M. Pestalozzi , V. Minier , F. Motte , J. Conway

We recently reported a population of protostellar candidates in the 20 km s$^{-1}$ cloud in the Central Molecular Zone of the Milky Way, traced by H$_2$O masers in gravitationally bound dense cores. In this paper, we report…

Methanol-water liquid mixtures have been investigated by high-energy synchrotron X-ray and neutron diffraction at low temperatures. We are thus able to report the first complete sets of both X-ray and neutron weighted total scattering…

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…

The role of magnetic fields during the protostellar phase of high-mass star-formation is a debated topic. In particular, it is still unclear how magnetic fields influence the formation and dynamic of disks and outflows. Most current…

Solar and Stellar Astrophysics · Physics 2015-05-14 G. Surcis , W. H. T. Vlemmings , R. Dodson , H. J. van Langevelde

We present definitive detection statistics for 12.2 GHz methanol masers towards a complete sample of 6.7 GHz methanol masers detected in the Methanol Multibeam survey south of declination -20 degrees. In total, we detect 250 12.2 GHz…

Astrophysics of Galaxies · Physics 2015-05-27 Shari Breen , Simon Ellingsen , James Caswell , James Green , Gary Fuller , Maxim Voronkov , Lyshia Quinn , Adam Avison

We report the first multi-epoch milliarcsecond resolution imaging of the 6.7-GHz class II methanol maser emission associated with the high-mass protocluster system NGC6334I. The observations covered a period of over 10 years in four epochs…

The ATCA, MERLIN and VLA interferometers were used to measure the absolute positions of 35 6.7 GHz methanol masers to subarcsecond or higher accuracy. Our measurements represent essential preparatory data for Very Long Baseline…

Astrophysics of Galaxies · Physics 2015-05-14 Y. Xu , M. A. Voronkov , J. D. Pandian , J. J. Li , A. M. Sobolev , A. Brunthaler , B. Ritter , K. M. Menten

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…

Solar and Stellar Astrophysics · Physics 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

The results of a survey searching for outflows using near-infrared imaging is presented. Targets were chosen from a compiled list of massive young stellar objects (YSOs) associated with methanol masers in linear distributions. Presently, it…

Astrophysics · Physics 2009-11-07 James M. De Buizer

The 6.7~GHz methanol maser transition is exclusively associated with young, high-mass stars and represents a potential target for astrometric studies, including accurate determination of their distance through trigonometric parallax…

Astrophysics of Galaxies · Physics 2025-10-21 Lucas J. Hyland , Simon P. Ellingsen , Mark J. Reid

Astrophysical observations show complex organic molecules (COMs) in the gas phase of protoplanetary disks. X-rays emitted from the central young stellar object (YSO) that irradiate interstellar ices in the disk, followed by the ejection of…

Earth and Planetary Astrophysics · Physics 2021-02-22 R. Basalgète , R. Dupuy , G. Féraud , C. Romanzin , L. Philippe , X. Michaut , J. Michoud , L. Amiaud , A. Lafosse , J. -H. Fillion , M. Bertin

The Australia Telescope Compact Array (ATCA) and the Mopra facility have been used to search for new southern class I methanol masers at 9.9, 25 (J=5) and 104 GHz, which are thought to trace more energetic conditions in the interface…

In this study some properties of the methanol-water mixture such as diffusivity, density, viscosity, and hydrogen bonding were calculated at different temperatures and atmospheric pressure using molecular dynamics simulations (MDS). The…

Atomic and Molecular Clusters · Physics 2017-08-08 Palazzo Mancini , Mara Cantoni

In circumstellar gas, the complex organic molecule methanol has been found almost exclusively around young stellar objects, and is thus regarded as a signpost of recent star formation. Here we report the first probable detection of methanol…

Methanol lines observations of a sample of low mass Class 0 protostars are presented. Using a 1D radiative transfer model, I show that several protostars have large abundance jumps in the inner hot and dense region of envelopes, probably…

Astrophysics · Physics 2007-05-23 S. Maret
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