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

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We have used the Australia Telescope Compact Array (ATCA) to search for a number of centimetre wavelength methanol transitions which are predicted to show weak maser emission towards star formation regions. Sensitive, high spatial and…

Astrophysics of Galaxies · Physics 2016-11-15 Antony Chipman , Simon Ellingsen , Andrej Sobolev , Dinah Cragg

We present a survey of 56 massive star-forming regions in the 44 GHz methanol maser transition made with the Karl G. Jansky Very Large Array (VLA); 24 of the 56 fields showed maser emission. The data allow us to demonstrate associations, at…

The Purple Mountain Observatory 13.7 m radio telescope has been used to search for 95 GHz (8$_0$--7$_1$A$^+$) class I methanol masers towards 1020 Bolocam Galactic Plane Survey (BGPS) sources, leading to 213 detections. We have compared the…

Astrophysics of Galaxies · Physics 2017-08-23 Wenjin Yang , Ye Xu , Xi Chen , Simon P. Ellingsen , Dengrong Lu , Binggang Ju , Yingjie Li

We report the results of a systematic survey for 95 GHz class I methanol masers towards a new sample of 192 massive young stellar object (MYSO) candidates associated with ongoing outflows (known as extended green objects or EGOs) identified…

Solar and Stellar Astrophysics · Physics 2015-05-28 Xi Chen , Simon P. Ellingsen , Zhi-Qiang Shen , Anita Titmarsh , Cong-Gui Gan

We investigate the kinematics of high mass protostellar objects within the high mass star forming region IRAS 19410+2336. We performed high angular resolution observations of 6.7-GHz methanol and 22 GHz water masers using the MERLIN…

Astrophysics of Galaxies · Physics 2021-05-25 M. S. Darwish , K. A. Edris , A. M. S. Richards , S. Etoka , M. S. Saad , M. M. Beheary , G. A Fuller

Class I methanol masers are believed to be produced in the shock-excited environment around star-forming regions. Many authors have argued that the appearance of various subsets of class I masers may be indicative of specific evolutionary…

The class II masers of methanol are associated with the early stages of formation of high-mass stars. Modelling of these dense, dusty environments has demonstrated that pumping by infrared radiation can account for the observed masers.…

Astrophysics · Physics 2009-11-11 D. M. Cragg , A. M. Sobolev , P. D. Godfrey

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…

Solar and Stellar Astrophysics · Physics 2016-12-07 Bridget McEwen , Loránt Sjouwerman , Ylva Pihlström

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)…

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…

Astrophysics of Galaxies · Physics 2014-06-04 L. Olmi , E. D. Araya , P. Hofner , S. Molinari , J. Morales Ortiz , L. Moscadelli , M. Pestalozzi

We present the third instalment of a series of catalogues presenting 12.2-GHz methanol maser observations made towards each of the 6.7-GHz methanol masers detected in the Methanol Multibeam (MMB) Survey. The current portion of the catalogue…

Context: We investigated the molecular gas associated with 6.7 GHz methanol masers throughout the Galaxy using a J=1-0 transition of the CO isotopologues. Methods:Using the 13.7-meter telescope at the Purple Mountain Observatory (PMO), we…

Solar and Stellar Astrophysics · Physics 2014-09-05 Zhiyuan Ren , Yuefang Wu , Tie Liu , Lixin Li , Di Li , Binggang Ju

We present 247-GHz molecular line observations of methanol (CH$_3$OH) toward sixteen massive star-forming regions, using the APEX telescope with an angular resolution of $25''$. The sample covers a range of evolutionary states, including…

We present a catalogue of 12.2-GHz methanol masers detected towards 6.7-GHz methanol masers observed in the unbiased Methanol Multibeam (MMB) survey in the longitude range 330\circ (through 360\circ) to 10\circ. This is the first portion of…

Astrophysics of Galaxies · Physics 2015-06-03 Shari Breen , Simon Ellingsen , James Caswell , James Green , Maxim Voronkov , Gary Fuller , Lyshia Quinn , Adam Avison

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

Class I CH$_3$OH masers trace interstellar shocks. They have received little attention mostly as a consequence of their low luminosities; this situation has changed recently and Class I masers are now routinely used as signposts of…

Astrophysics of Galaxies · Physics 2016-07-13 S. Leurini , K. M. Menten , C. M. Walmsley

We performed a systematic 6.7 GHz Class \uppercase\expandafter{\romannumeral2} methanol maser survey using the Shanghai Tianma Radio Telescope toward targets selected from the all-sky \emph{Wide-Field Infrared Survey Explorer (WISE)} point…

Astrophysics of Galaxies · Physics 2019-04-30 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 , Zhiyuan Ren

22 GHz water and 6.7 GHz methanol masers are usually thought as signposts of early stages of high-mass star formation but little is known about their associations and the physical environments they occur in. The aim was to obtain accurate…

Astrophysics of Galaxies · Physics 2015-05-19 A. Bartkiewicz , M. Szymczak , Y. M. Pihlström , H. J. van Langevelde , A. Brunthaler , M. J. Reid

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…

Astrophysics of Galaxies · Physics 2015-05-18 Lorant O. Sjouwerman , Ylva M. Pihlstrom , Vincent L. Fish

Context: Methanol masers of Class I (collisionally-pumped) and Class II (radiatively-pumped) have been studied in great detail in our Galaxy in a variety of astrophysical environments such as shocks and star-forming regions and are helpful…