English
Related papers

Related papers: On the Relationship of UC H II Regions and Class I…

200 papers

The Australia Telescope Compact Array (ATCA) has been used to search for methanol maser emission at 6.7 GHz towards OMC-1. Two features peaking at 7.2 km/s and -1.1 km/s have been detected. The former has at least two components close in…

Astrophysics · Physics 2009-11-13 M. A. Voronkov , A. M. Sobolev , S. P. Ellingsen , A. B. Ostrovskii

We report the detection of emission from the 6.7 GHz 5(1)-6(0)A+ transition of methanol towards the center of the nearby galaxy NGC4945. This is the first detection of emission in this transition beyond the local group. The isotropic…

Astrophysics of Galaxies · Physics 2018-10-25 Simon Ellingsen , Tiege McCarty , Shari Breen , Maxim Voronkov

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

We have used the Australia Telescope Compact Array (ATCA) to search for emission from the $4_{-1} \rightarrow 3_{0}E$ transition of methanol (36.2 GHz) towards the center of the nearby starburst galaxy NGC253. Two regions of emission were…

Astrophysics of Galaxies · Physics 2015-06-22 Simon Ellingsen , Xi Chen , Hai-Hua Qiao , Willem Baan , Tao An , Juan Li , Shari Breen

We report the results of 10 years of monitoring of six regularly varying 6.7 GHz methanol masers using the Hartebeesthoek 26m telescope. Observations were done at intervals of 1--2 weeks, with faster sampling during flaring episodes. Four…

Solar and Stellar Astrophysics · Physics 2013-11-08 S. Goedhart , J. P. Maswanganye , M. J. Gaylard , D. J. van der Walt

In this contribution I will attempt to show that the study of galactic 6.7 and 12.2GHz methanol masers themselves, as opposed to the use of methanol masers as signposts, can yield important conclusions contributing to the understanding of…

Astrophysics · Physics 2009-11-13 Michele Pestalozzi

I present here the summary of results from a survey by De Buizer (2003) searching for outflows using near-infrared imaging. Targets were massive young stellar objects associated with methanol masers in linear distributions. Presently, it is…

Astrophysics · Physics 2007-05-23 James M. De Buizer

We present a multiwavelength study of five methanol maser sites which are not directly associated with a strong ($>100$ mJy) radio continuum source: G 31.28+0.06, G 59.78+0.06, G 173.49+2.42 (S231, S233IR), G 188.95+0.89 (S252, AFGL5180)…

Astrophysics · Physics 2009-11-10 V. Minier , M. G. Burton , T. Hill , M. R. Pestalozzi , C. R. Purcell , G. Garay , A. Walsh , S. Longmore

We report VLBI observations of methanol masers in the brightest 5(1)-6(0) A+ transition at 6.7 GHz in NGC 281W, 18151-1208 and 19388+2357. Using the fringe rate method absolute positions were obtained for all observed sources. A linear…

Astrophysics · Physics 2007-05-23 M. A. Voronkov , V. I. Slysh , F. Palagi , G. Tofani

At centimeter wavelengths, single-dish observations have suggested that the Sagittarius (Sgr) B2 molecular cloud at the Galactic Center hosts weak maser emission from several organic molecules, including CH$_2$NH, HNCNH, and HCOOCH$_3$.…

Astrophysics of Galaxies · Physics 2024-04-22 Ci Xue , Anthony Remijan , Alexandre Faure , Emmanuel Momjian , Todd R. Hunter , Ryan A. Loomis , Eric Herbst , Brett McGuire

We have used the Swedish ESO Submillimetre Telescope (SEST) to search for new class II methanol maser transitions towards the southern source G345.01+1.79. Over a period of 5 days we observed 11 known or predicted class II methanol maser…

Astrophysics of Galaxies · Physics 2015-06-11 S. P. Ellingsen , A. M. Sobolev , D. M. Cragg , P. D. Godfrey

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 present high-resolution Karl G. Jansky Very Large Array observations of the 22 GHz $\mathrm{H_2O}$ maser line in the extended Sagittarius B2 cloud. We detect 499 $\mathrm{H_2O}$ masers across the observed velocities between -39 and 172…

Methanol masers at 6.7 GHz are known to be tracers of high-mass star formation in our Galaxy. In this paper, we study the large scale physical conditions in the star forming clumps/cores associated with 6.7 GHz methanol masers using…

Solar and Stellar Astrophysics · Physics 2015-06-05 J. D. Pandian , F. Wyrowski , K. M. Menten

Spectra of 6.7 GHz methanol masers from 21 pointings of known star-forming regions are reported. The C-band observations, using the Green Bank Telescope in full Stokes mode, have measured how polarization properties vary across the maser…

Astrophysics of Galaxies · Physics 2026-05-19 Paul Fallon , Derck P. Smits

We present new observations of the quiescent giant molecular cloud GCM0.253+0.016 in the Galactic center, using the upgraded Karl G. Jansky Very Large Array. Observations were made at wavelengths near 1 cm, at K (24 to 26 GHz) and Ka (27…

Astrophysics of Galaxies · Physics 2015-05-27 E. A. C. Mills , N. Butterfield , D. A. Ludovici , C. C. Lang , J. Ott , M. R. Morris , S. Schmitz

The Australia Telescope Compact Array (ATCA) has been used to determine positions for many southern methanol maser sites, with accuracy better than 1 arcsec. The results are presented here as a catalogue of more than 350 distinct sites,…

Astrophysics of Galaxies · Physics 2015-05-13 J. L. Caswell

We present the results of a survey of a small sample (14) of low-mass protostars (L_IR < 10^3 Lsun) for 6.7 GHz methanol maser emission performed using the ATNF Parkes radio telescope. No new masers were discovered. We find that the lower…

Astrophysics · Physics 2009-11-11 Tyler L. Bourke , A. R. Hyland , Garry Robinson

We present a catalog of low-mass dense cores observed with the SHARC-II instrument at 350 microns. Our observations have an effective angular resolution of 10", approximately 2.5 times higher than observations at the same wavelength…

Astrophysics of Galaxies · Physics 2016-07-27 Akshaya Suresh , Michael M. Dunham , Héctor G. Arce , Neal J. Evans , Tyler L. Bourke , Manuel Merello , Jingwen Wu

High mass stars play an important role in the Interstellar Medium, but much remains to be known about their formation. Class I methanol masers may be unique tracers of an early stage of high mass star formation, and a better understanding…

Astrophysics of Galaxies · Physics 2022-05-18 Nycole Wenner , A. P. Sarma , E. Momjian