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We report the results of our systematic survey for Galactic 6.7 GHz Class II CH$_3$OH maser emission toward a sample of young stellar objects. The survey was conducted with the Shanghai Tianma Radio Telescope (TMRT). The sample consists of…

Astrophysics of Galaxies · Physics 2019-06-14 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

CH2 transitions between 68 and 71 GHz were first detected toward the Orion-KL and W51 Main SFRs. Given their upper level energies of 225 K, they were thought to arise in dense, hot molecular cores near newly formed stars. However, this has…

Astrophysics of Galaxies · Physics 2021-03-10 A. M. Jacob , K. M. Menten , Y. Gong , P. Bergman , M. Tiwari , S. Bruenken , A. O. H. Olofsson

We present high angular resolution observations of water masers at 1.3 cm and radio continuum emission at 1.3, 3.6 and 6 cm towards the Bok globule CB 54 using the Very Large Array. At 1.3 cm, with subarsecond angular resolution, we detect…

Astrophysics of Galaxies · Physics 2015-05-13 I. de Gregorio-Monsalvo , J. F. Gomez , G. Anglada , J. M. Torrelles , T. B. H. Kuiper , O. Suarez , N. A. Patel

We present the results of an interferometric study of 38 millimeter-wave lines of CH3OH in the region around the water maser source W3(H2O) and a region extending about 30" to the south and west of the hydroxyl maser source W3(OH). The…

We report the first detection of a radio-continuum and molecular jet associated with a dominant blue-shifted maser source, G353.273+0.641. A radio jet is extended 3000 au along NW-SE direction. H$_{2}$O masers are found to be clustered in…

Solar and Stellar Astrophysics · Physics 2015-06-11 Kazuhito Motogi , Kazuo Sorai , Kotaro Niinuma , Koichiro Sugiyama , Mareki Honma , Kenta Fujisawa

Context: OH maser emission is known to be associated with high mass star forming regions. Towards some of these regions, OH masers are associated with HII regions. Towards others, believed to be in an earlier evolutionary state, OH masers…

Astrophysics of Galaxies · Physics 2011-07-05 K. A. Edris

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

MERLIN phase-referenced polarimetric observations towards the W51 complex were carried out in March 2006 in the Class II methanol maser transition at 6.668 GHz and three of the four excited OH maser hyperfine transitions at 6 GHz. Methanol…

Astrophysics of Galaxies · Physics 2015-06-04 Sandra Etoka , Malcolm D. Gray , Gary A. Fuller

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

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…

Astrophysics of Galaxies · Physics 2015-05-18 S. V. Kalenskii , L. E. B. Johansson , P. Bergman , S. Kurtz , P. Hofner , C. M. Walmsley , V. I. Slysh

We present (sub)millimeter imaging at 0.5'' resolution of the massive star-forming region G358.93-0.03 acquired in multiple epochs at 2 and 3 months following the recent flaring of its 6.7 GHz methanol maser emission. Using SMA and ALMA, we…

Our mid-infrared and near-infrared surveys over the last five years have helped to strengthen and clarify the relationships between water, methanol, and OH masers and the star formation process. Our surveys show that maser emission seems to…

Astrophysics · Physics 2009-11-11 James M. De Buizer , James T. Radomski , Charles M. Telesco , Robert K. Pina

Sensitive and high angular resolution ($\sim$ $0\rlap.{"}7$) (sub)millimeter line and continuum observations of the massive star forming region W3(OH) made with the Submillimeter Array are presented. We report the first detection of two…

Astrophysics of Galaxies · Physics 2015-05-30 Luis A. Zapata , Carolina Rodríguez-Garza , Luis F. Rodríguez , Josep M. Girart , Huei-Ru Chen

Arecibo 305-m Telescope observations between 2008 and 2018 detected a radio continuum and spectral-line outburst in the nearby galaxy, NGC 660. Excited-OH maser emission/absorption lines near 4.7 GHz, and H$_2$CO absorption at 4.83 GHz…

Astrophysics of Galaxies · Physics 2024-10-01 C. J. Salter , T. Ghosh , R. F. Minchin , E. Momjian , B. Catinella , M. Lebron , M. S. Lerner

Observations of Serpens have been performed at the JCMT using Harp-B. Maps over a 4.5'x5.4' region were made in a frequency window around 338 GHz, covering the 7-6 transitions of methanol. Emission is extended over each source, following…

Solar and Stellar Astrophysics · Physics 2015-05-18 L. E. Kristensen , E. F. van Dishoeck , T. A. van Kempen , H. M. Cuppen , C. Brinch , J. K. Jørgensen , M. R. Hogerheijde

Although the role of magnetic fields in launching molecular outflows in massive YSOs has been convincingly demonstrated by theoretical arguments, observationally, the alignment of the magnetic field lines with the molecular outflows is…

Astrophysics of Galaxies · Physics 2022-02-02 G. Surcis , W. H. T. Vlemmings , H. J. van Langevelde , B. Hutawarakorn Kramer , A. Bartkiewicz

We conducted VLA C-configuration observations to measure positions and luminosities of Galactic Class II 6.7 GHz methanol masers and their associated ultra-compact H II regions. The spectral resolution was 3.90625 kHz and the continuum…

Astrophysics of Galaxies · Physics 2016-12-14 Bo Hu , Karl M. Menten , Yuanwei Wu , Anna Bartkiewicz , Kazi Rygl , Mark J. Reid , James S. Urquhart , Xingwu Zheng

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…

Recent studies of methanol and ground-state OH masers at very high spectral resolution have shed new light on small-scale maser processes. The nearby source W3(OH), which contains numerous bright masers in several different transitions,…

Astrophysics · Physics 2009-11-13 Vincent L. Fish , Loránt O. Sjouwerman

This paper presents a large spectral line and continuum survey of 8 deeply embedded, low-mass protostellar cores using the Submillimeter Array. Each source was observed in high excitation lines of some of the most common molecular species,…

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