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We have constructed the largest sample of dust-associated class II 6.7 GHz methanol masers yet obtained. New measurements from the the Methanol MultiBeam (MMB) Survey were combined with the 870 $\mu$m APEX Telescope Large Area Survey of the…

The Australia Telescope Compact Array (ATCA) has been used to make the first full polarization observations of 6.7 GHz methanol masers. Linear polarization was detected towards all four sources observed, at levels between a few and 10%,…

Astrophysics · Physics 2007-05-23 S. P. Ellingsen

We report results of EVN interferometric study of two star-forming regions L1206 and GL2789 in the brightest methanol maser line at 6.7 GHz. Using measured absolute positions both methanol masers were identified with protostars which are…

Astrophysics · Physics 2007-05-23 M. A. Voronkov , V. I. Slysh

We report the result of a systematic methanol observation toward IRAS 19312+1950. The properties of the SiO, H2O and OH masers of this object are consistent with those of mass-losing evolved stars, but some other properties are difficult to…

Solar and Stellar Astrophysics · Physics 2015-08-06 Jun-ichi Nakashima , Andrej M. Sobolev , Svetlana V. Salii , Yong Zhang , Bosco H. K. Yung , Shuji Deguchi

The near infrared (1-2um) and the thermal infrared (3-25um) trace many of the environments in which masers are thought to reside, including shocks, outflows, accretion disks, and the dense medium near protostars. After a number of recent…

Astrophysics · Physics 2009-11-13 James De Buizer

We present the results of the first complete survey of the Large and Small Magellanic Clouds for 6668-MHz methanol and 6035-MHz excited-state hydroxyl masers. In addition to the survey, higher-sensitivity targeted searches towards known…

{The variability study of 6.7\,GHz methanol masers has become a useful way to improve our understanding of the physical conditions in high-mass star-forming regions.} {Based on the single-dish monitoring using the Irbene telescopes, we…

Astrophysics of Galaxies · Physics 2023-07-10 A Aberfelds , A Bartkiewicz , M Szymczak , J Šteinbergs , G Surcis , A Kobak , M Durjasz , I Shmeld

We present high-frequency (18-24 GHz) radio continuum observations towards 335 methanol masers, excellent signposts for young, embedded high-mass protostars. These complete the search for hypercompact HII (HCHII) regions towards young…

Astrophysics of Galaxies · Physics 2025-06-04 A. L. Patel , J. S. Urquhart , A. Y. Yang , L. K. Morgan , K. M. Menten , M. A. Thompson , T. Moore , I. Grozdanova , S. Khan , T. Csengeri

We present the results of a high angular resolution Very Large Array (VLA) Class I 44 GHz and Class II 6.7 GHz methanol maser survey of a sample of ~20 massive young stellar object (MYSO) outflow candidates selected on the basis of extended…

Solar and Stellar Astrophysics · Physics 2009-09-28 C. J. Cyganowski , C. L. Brogan , T. R. Hunter , E. Churchwell

We present the first EVN parallax measurements of 6.7 GHz methanol masers in star forming regions of the Galaxy. The 6.7 GHz methanol maser transition is a very valuable astrometric tool, for its large stability and confined velocity…

Astrophysics · Physics 2008-12-09 K. L. J. Rygl , A. Brunthaler , K. M. Menten , M. J. Reid , H. J. van Langevelde

We present the unambiguous discovery of six new class II methanol maser transitions, three of which are torsionally excited (vt=1). The newly discovered 6.18-GHz 17_-2 -> 18_-3 E (vt=1), 7.68-GHz 12_4 -> 13_3 A- (vt=0), 7.83-GHz 12_4 ->…

Astrophysics of Galaxies · Physics 2019-05-15 S. L. Breen , A. M. Sobolev , J. F. Kaczmarek , S. P. Ellingsen , T. P. McCarthy , M. A. Voronkov

G339.88-1.26 is considered to be a good candidate for a massive star with a circumstellar disk. This has been supported by the observations of linearly distributed methanol maser spots believed to delineate this disk, and mid-infrared…

We present high angular resolution (FWHM_beam < 0.2") observations of the 23.1-GHz methanol (CH_3OH) transition toward the massive-star forming region NGC 7538 IRS 1. The two velocity components previously reported by Wilson et al. are…

Astrophysics of Galaxies · Physics 2015-05-18 Roberto Galván-Madrid , Gabriela Montes , Edgar A. Ramírez , Stan Kurtz , Esteban Araya , Peter Hofner

We have made measurements to determine the parallax and proper motion of the three 6.7-GHz methanol masers G305.200$+$0.019, G305.202$+$0.208 and G305.208$+$0.206. The combined parallax is found to be 0.25$\pm $0.05 mas, corresponding to a…

Astrophysics of Galaxies · Physics 2016-12-14 V Krishnan , S P Ellingsen , M J Reid , H E Bignall , J McCallum , C J Phillips , C Reynolds , J Stevens

The source G25.65+1.05 (RAFGL7009S, IRAS 18316-0602) is the least studied of the three regions of massive star formation known to show exceptionally powerful H$_2$O maser bursts. We report spectral line observations of the H$_2$O maser at…

Astrophysics of Galaxies · Physics 2019-11-06 O. S. Bayandina , R. A. Burns , S. E. Kurtz , N. N. Shakhvorostova , I. E. Val'tts

We report the detection of a new H2CO maser in the massive star forming region G23.71-0.20 (IRAS 18324-0820), i.e., the fifth region in the Galaxy where H2CO maser emission has been found. The new H2CO maser is located toward a compact HII…

Astrophysics · Physics 2009-11-11 E. Araya , P. Hofner , W. M. Goss , S. Kurtz , H. Linz , L. Olmi

The ATCA has been used to measure positions with arcsecond accuracy for 379 masers at the 22-GHz transition of water. The principal observation targets were 202 OH masers of the variety associated with star formation regions (SFR)s in the…

Astrophysics of Galaxies · Physics 2015-05-18 Shari Breen , James Caswell , Simon Ellingsen , Chris Phillips

The University of Tasmania Mt Pleasant 26-m and Ceduna 30-m radio telescopes have been used to search for 6.7-GHz class II methanol masers towards two hundred GLIMPSE sources. The target regions were selected on the basis of their…

Astrophysics · Physics 2008-11-26 S. P. Ellingsen

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…

Astrophysics · Physics 2011-03-02 H. S. P. Mueller , K. M. Menten , H. Maeder

A systematic study is performed on radio properties of H$_{2}$O megamaser host Seyfert 2 galaxies, through multi-band radio continuum observations (at 11cm, 6.0 cm, 3.6 cm, 2.0 cm and 1.3 cm) with the Effelsberg 100-m radio telescope within…

Astrophysics of Galaxies · Physics 2017-01-18 Z. W. Liu , J. S. Zhang , C. Henkel , J. Liu , P. Müller , J. Z. Wang Q. Guo , J. Wang , J. Li
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