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Related papers: Methanol masers as tools to study high-mass star f…

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We present high angular resolution Submillimeter Array (SMA) and Karl G. Jansky Very Large Array (VLA) observations of the massive protocluster G18.67+0.03. Previously targeted in maser surveys of GLIMPSE Extended Green Objects (EGOs), this…

Astrophysics of Galaxies · Physics 2015-06-11 C. J. Cyganowski , C. L. Brogan , T. R. Hunter , Q. Zhang , R. K. Friesen , R. Indebetouw , C. J. Chandler

This is the second paper in a series of catalogues of 22-GHz water maser observations towards the 6.7-GHz methanol masers from the Methanol Multibeam (MMB) Survey. In this paper we present our water maser observations made with the…

Astrophysics of Galaxies · Physics 2016-03-23 A. M. Titmarsh , S. P. Ellingsen , S. L. Breen , J. L. Caswell , M. A. Voronkov

Methanol masers at 6.7 GHz are well known tracers of high-mass star-forming regions. However, their origin is still not clearly understood. We aimed to determine the morphology and velocity structure for a large sample of the maser emission…

Astrophysics of Galaxies · Physics 2016-03-02 Anna Bartkiewicz , Marian Szymczak , Huib J. van Langevelde

Six young bipolar outflows in regions of low-to-intermediate-mass star formation were observed in the 7_0-6_1A+, 8_0-7_1A+, and 5_{-1}-4_0E methanol lines at 44, 95, and 84 GHz, respectively. Narrow features were detected towards NGC…

Astrophysics · Physics 2009-11-11 S. V. Kalenskii , V. G. Promyslov , V. I. Slysh , P. Bergman , A. Winnberg

In this paper we use observations of molecular tracers in metal rich and alpha-enhanced galaxies to study the effect of abundance changes on molecular chemistry. We selected a sample of metal rich spiral and star bursting objects from the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Timothy A. Davis , Estelle Bayet , Alison Crocker , Selcuk Topal , Martin Bureau

We report the results of a search for 6.7 GHz methanol (CH3OH) maser emission in OH megamaser galaxies at 0.11<z<0.27. No detections were made in the 25 objects observed down to rms noise levels of roughly 0.6 mJy in 150 kHz channels. The…

Astrophysics · Physics 2009-11-07 Jeremy Darling , Paul Goldsmith , Di Li , Riccardo Giovanelli

We derive kinematic distances to the 86 6.7 GHz methanol masers discovered in the Arecibo Methanol Maser Galactic Plane Survey. The systemic velocities of the sources were derived from 13CO (J=2-1), CS (J=5-4), and NH3 observations made…

Astrophysics of Galaxies · Physics 2014-11-20 J. D. Pandian , K. M. Menten , P. F. Goldsmith

We report detection of moderate to high-mass star formation in an infrared dark cloud (G11.11-0.12) where we discovered class II methanol and water maser emissions at 6.7 GHz and 22.2 GHz, respectively. We also observed the object in…

Astrophysics · Physics 2009-11-13 Thushara Pillai , Friedrich Wyrowski , Karl M. Menten , Endrik Kr"ugel

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

We have searched for emission from the 36.2 GHz ($4_{-1} \rightarrow 3_0$E) methanol transition towards NGC 4945, using the Australia Telescope Compact Array. 36.2 GHz methanol emission was detected offset south-east from the Galactic…

Astrophysics of Galaxies · Physics 2018-11-21 Tiege P. McCarthy , Simon P. Ellingsen , Xi Chen , Shari L. Breen , Maxim A. Voronkov , Hai-hua Qiao

We report the negative results from a search for 6.7 GHz methanol masers in the nearby spiral galaxy M33. We observed 14 GMCs in the central 4 kpc of the Galaxy, and found 3 sigma upper limits to the flux density of ~9 mJy in spectral…

Astrophysics · Physics 2009-11-13 P. F. Goldsmith , J. D. Pandian , A. A. Deshpande

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 the discovery of periodic flares of 6.7GHz methanol maser in the young massive stellar object G22.357+0.066. The target was monitored in the methanol maser line over 20 months with the Torun 32m telescope. The emission was also…

Astrophysics of Galaxies · Physics 2015-05-28 M. Szymczak , P. Wolak , A. Bartkiewicz , H. J. van Langevelde

The Methanol MultiBeam survey (MMB) provides the most complete sample of Galactic massive young stellar objects (MYSOs) hosting 6.7GHz class II methanol masers. We characterise the properties of these maser sources using dust emission…

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,…

Four Class I maser sources were detected at 44, 84, and 95 GHz toward chemically rich outflows in the regions of low-mass star formation NGC 1333I4A, NGC 1333I2A, HH25, and L1157. One more maser was found at 36 GHz toward a similar outflow,…

Astrophysics of Galaxies · Physics 2015-06-04 S. V. Kalenskii , V. I. Slysh , L. E. B. Johansson , P. Bergman , S. Kurtz , P. Hofner , C. M. Walmsley

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 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…

Hypercompact (HC) HII regions are, by nature, very young HII regions, associated with the earliest stages of massive star formation. They may represent the transition phase as an early B-type star grows into an O-type star. Unfortunately,…

Astrophysics of Galaxies · Physics 2015-05-28 Alvaro Sanchez-Monge , Jagadheep D. Pandian , Stan Kurtz

We have observed a sample of 288 molecular outflow sources including 123 high-mass and 165 low-mass sources to search for class I methanol masers at 95 GHz transition and to investigate relationship between outflow characteristics and class…

Solar and Stellar Astrophysics · Physics 2015-06-12 Cong-Gui Gan , Xi Chen , Zhi-Qiang Shen , Ye Xu , Bing-Gang Ju