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相关论文: Maser action in methanol transitions

200 篇论文

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…

星系天体物理 · 物理学 2015-05-18 Shari Breen , James Caswell , Simon Ellingsen , Chris Phillips

The Australia Telescope Compact Array (ATCA) has been used to make the first extensive search for the class I methanol masers at 9.9 GHz. In total, 48 regions of high-mass star formation were observed. In addition to masers in W33-Met…

星系天体物理 · 物理学 2015-05-18 M. A. Voronkov , J. L. Caswell , S. P. Ellingsen , A. M. Sobolev

Results of a survey of Galactic star-forming regions in the lines of methanol 8_{-1}-7_0E at 229.8 GHz, 3_{-2}-4_{-1}E at 230.0 GHz, 0_0-1_{-1}E at 108.9 GHz, and a series of methanol lines J_1-J_0E near 165 GHz are presented. Two masers,…

天体物理学 · 物理学 2007-05-23 S. V. Kalenskii , V. I. Slysh , I. E. Val'tts

We present an interferometric survey of the 44 GHz class I methanol maser transition toward a sample of 69 sources consisting of High Mass Protostellar Object candidates and Ultracompact (UC) H II regions. We found a 38% detection rate (16…

星系天体物理 · 物理学 2016-02-17 A. I. Gómez-Ruiz , S. E. Kurtz , E. D. Araya , P. Hofner , L. Loinard

We show that in many methanol maser sources the masers are located in lines, with a velocity gradient along them which suggests that the masers are situated in edge-on circumstellar, or protoplanetary, disks. We present VLBI observations of…

We have selected the positions of 54 6.7GHz methanol masers from the Methanol Multibeam Survey catalogue, covering a range of longitudes between $20^{\circ}$ and $34^{\circ}$ of the Galactic Plane. These positions were mapped in the J=3-2…

The results of a maser survey toward ninety-nine protostars in the Orion molecular cloud complex are presented. The target sources are low-mass protostars identified from infrared observations. Single-dish observations were carried out in…

星系天体物理 · 物理学 2015-06-17 Miju Kang , Jeong-Eun Lee , Minho Choi , Yunhee Choi , Kee-Tae Kim , James Di Francesco , Yong-Sun Park

We present the second portion of a catalogue of 12.2-GHz methanol masers detected towards 6.7-GHz methanol masers observed in the unbiased Methanol Multibeam (MMB) Survey. Using the Parkes radio telescope we have targeted all 207 6.7-GHz…

星系天体物理 · 物理学 2015-06-05 Shari Breen , Simon Ellingsen , James Caswell , James Green , Maxim Voronkov , Gary Fuller , Lyshia Quinn , Adam Avison

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 review properties of all known collisionally pumped (class I) methanol maser series based on observations with the Australia Telescope Compact Array (ATCA) and the Mopra radio telescope. Masers at 36, 84, 44 and 95 GHz are most…

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

6.7 GHz methanol masers are the brightest of class II methanol masers that are regarded as excellent signposts in the formation of young massive stars. We present here a molecular line study of 68 6.7 GHz methanol maser hosts chosen from…

星系天体物理 · 物理学 2021-11-09 Sonu Tabitha Paulson , Jagadheep D. Pandian

Context. Class II methanol masers at 6.7 and 12.2 GHz occur close to high-mass young stellar objects (HMYSOs). When they are observed simultaneously, such studies may contribute to refining the characterisation of local physical conditions.…

星系天体物理 · 物理学 2021-04-28 M. Durjasz , M. Szymczak , P. Wolak , A. Bartkiewicz

We report the detection of bursts of 6.7 GHz methanol maser emission in a high-mass star-forming region, G33.64-0.21. One of the spectral components of the maser in this source changed its flux density by 7 times that of the previous day,…

Using the Haystack Observatory 37-m radio telescope we have undertaken a search for emission in the 2(0)-3(1)E rotational transition of methanol in its first torsionally excited state (v_t=1) at 44.9 GHz. We examined seven galactic sources…

天体物理学 · 物理学 2009-11-07 M. A. Voronkov , M. C. Austin , A. M. Sobolev

We have used the Australia Telescope Compact Array (ATCA) to search for 6.7-GHz methanol maser emission towards 87 galaxies. We chose the target sources using several criteria, including far-IR luminosities and the presence of known OH…

天体物理学 · 物理学 2020-11-25 C. J. Phillips , R. P. Norris , S. P. Ellingsen , D. P. Rayner

We report the detection of ammonia masers in the non-metastable (6, 3), (7, 5) and (6, 5) transitions, the latter is the first unambiguous maser detection of that transition ever made. Our observations include the first VLBI detection of…

We analyzed the 3-mm wavelength spectral line survey of 408 ATLASGAL clumps observed with the IRAM 30m-telescope, focusing on the class I methanol masers with frequencies near 84, 95 and 104.3 GHz. We detect narrow, maser-like features…

星系天体物理 · 物理学 2023-07-12 W. Yang , Y. Gong , K. M. Menten , J. S. Urquhart , C. Henkel , F. Wyrowski , T. Csengeri , S. P. Ellingsen , A. R. Bemis , J. Jang

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…

星系天体物理 · 物理学 2015-03-18 A. Bartkiewicz , M. Szymczak , H. J. van Langevelde , J. M. De Buizer , Y. Pihlström

A survey of young bipolar outflows in regions of low-to-intermediate-mass star formation has been carried out in two class I methanol maser transitions: 7_0-6_1A+ at 44 GHz and 4_{-1}-3_0E at 36 GHz. We detected narrow features towards NGC…

星系天体物理 · 物理学 2015-05-18 S. V. Kalenskii , L. E. B. Johansson , P. Bergman , S. Kurtz , P. Hofner , C. M. Walmsley , V. I. Slysh