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Related papers: The relationship between Class I and Class II meth…

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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

Single point observations are presented in NH3 (1,1) and (2,2) inversion transitions using the Effelsberg 100 m telescope for a sample of 100 6.7 GHz methanol masers and mapping observations in the 12CO and 13CO (1-0) transitions using the…

Astrophysics of Galaxies · Physics 2016-10-05 F. C. Li , Y. Xu , Y. W. Wu , J. Yang , D. R. Lu , K. M. Menten , C. Henkel

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 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

Class\,I methanol masers provide sensitive information about the shocked environment around star-forming regions. Among the brightest Class~I methanol masers, we have those in the $J_{-1}\rightarrow(J-$ 1)$_{0}-E$ line series, currently…

We report the beginning of the astronomical masers investigations in the 3-mm bandwidth at the radio telescope RT-22 (CrAO, Ukraine). For this purpose the special complex for maser lines investigation in 85...115 GHz frequency band is…

Astrophysics · Physics 2007-12-11 S. Yu. Zubrin , A. V. Antyufeyev , V. V. Myshenko , V. M. Shulga

We have carried out a multi-epoch simultaneous survey of 22 GHz H$_2$O and 44 GHz Class I CH$_3$OH masers toward 103 ultracompact HII regions (UCHIIs) between 2010 and 2017. We detected H$_2$O and CH$_3$OH maser emission in 74 (72%) and 55…

Solar and Stellar Astrophysics · Physics 2019-09-04 Won-Ju Kim , Kee-Tae Kim , Kwang-Tae Kim

We present a continuing study of a sample 44 molecular outflows, observed in 13CO lines, closely associated with 6.7GHz methanol masers, hence called Methanol Maser Associated Outflows (MMAOs). We compare MMAO properties with those of…

We present the results of studies of a new class of 6.7 GHz methanol maser sources with a ring-like emission structure discovered recently with the EVN. We have used the VLA to search for water masers at 22 GHz and radio continuum at 8.4…

Astrophysics of Galaxies · Physics 2015-03-18 A. Bartkiewicz , M. Szymczak , H. J. van Langevelde , J. M. De Buizer , Y. Pihlström

The revised version of the class I methanol maser catalog is presented. It contains 198 sources - new class I methanol masers detected in the direction of EGOs were added to the previous number (~160 sources have been published in the first…

Astrophysics of Galaxies · Physics 2010-06-18 I. E. Val'tts , G. M. Larionov , O. S. Bayandina

The 6.7 GHz methanol maser is exclusively associated with high-mass star formation. However, it remains unclear what structures harbour the methanol masers. Cepheus A is one of the closest regions of massive star formation, making it an…

Solar and Stellar Astrophysics · Physics 2015-05-20 K. J. E. Torstensson , H. J. van Langevelde , W. H. T. Vlemmings , S. Bourke

The 6.7 GHz maser transition of methanol has been found exclusively towards massive star forming regions. A majority of the masers have been found to lack the presence of any associated radio continuum. This could be due to the maser…

Astrophysics of Galaxies · Physics 2015-05-19 J. D. Pandian , E. Momjian , Y. Xu , K. M. Menten , P. F. Goldsmith

Recently, a comparison between the locations of 6.7-GHz methanol masers and dust continuum emission has renewed speculation that these masers can be associated with evolved stars. The implication of such a scenario would be profound,…

The Cygnus X complex is covered by the Global View of Star Formation in the Milky Way (GLOSTAR) survey, an unbiased radio-wavelength Galactic plane survey, in 4--8 GHz continuum radiation and several spectral lines. The GLOSTAR survey…

To investigate whether distinctions exist between low and high-luminosity Class II 6.7-GHz methanol masers, we have undertaken multi-line mapping observations of various molecular lines, including the NH3(1,1), (2,2), (3,3), (4,4) and…

Astrophysics of Galaxies · Physics 2010-07-13 Y. W. Wu , Y. Xu , J. D. Pandian , J. Yang , C. Henkel , K. M. Menten , S. B. Zhang

A sensitive search for 6.7--GHz methanol maser emission has been made towards 10 galaxies that have yielded detectable microwave molecular--line transitions. These include several which show OH megamaser or superluminous \water\/ maser…

Astrophysics · Physics 2015-06-24 S. P. Ellingsen , R. P. Norris , J. B. Whiteoak , R. A. Vaile , P. M. McCulloch , M. Price

We present a study of signatures of on-going star formation in a sample of protostellar objects with enhanced 4.5 {\mu}m emission ('green' sources) near the Galactic center. To understand how star formation in the Galactic center region…

Astrophysics of Galaxies · Physics 2015-05-27 Edward T. Chambers , Farhad Yusef-Zadeh , Doug Roberts

We report the discovery of the Zeeman effect in the 44 GHz Class I methanol maser line. The observations were carried out with 22 antennas of the EVLA toward a star forming region in OMC-2. Based on our adopted Zeeman splitting factor of z…

Astrophysics of Galaxies · Physics 2015-05-27 A. P. Sarma , E. Momjian

We have used the Australian Long Baseline Array (LBA) to produce milliarcsecond images of five sites of methanol maser emission at 6.7 GHz. These are all sites that have linear morphologies at arcsecond resolutions, which have been…

Astrophysics · Physics 2009-11-10 R. Dodson , R. Ojha , S. P. Ellingsen

We present accurate absolute astrometry of 6.7 GHz methanol masers detected in the Arecibo Methanol Maser Galactic Plane Survey using MERLIN and the Expanded Very Large Array (EVLA). We estimate the absolute astrometry to be accurate to…

Solar and Stellar Astrophysics · Physics 2015-05-27 J. D. Pandian , E. Momjian , Y. Xu , K. M. Menten , P. F. Goldsmith