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Related papers: H2O masers in a jet-driven bowshock: Episodic ejec…

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Between 1987 and 2023 we carried out single-dish monitoring campaigns of water-maser emission at 22 GHz in the circumstellar envelopes (CSEs) of four stars: RCas, oCet, RLeo and ChiCyg. The variability in integrated flux in RCas and oCet…

Astrophysics of Galaxies · Physics 2025-06-26 Jan Brand , Dieter Engels , Alessandra Zanichelli , Sandra Etoka

We present first results of the H_2O Southern Galactic Plane Survey (HOPS), using the Mopra radiotelescope with a broad band backend and a beam size of about 2'. We have observed 100 square degrees of the southern Galactic plane at 12mm…

We present observations of IRAS 16293-2422 using the Submillimeter Array (SMA) at 300 GHz, and the Very Large Array (VLA) at frequencies from 1.5 to 43 GHz. This source was already known to be a binary system with components A and B…

Astrophysics · Physics 2009-11-13 Claire J. Chandler , Crystal L. Brogan , Yancy L. Shirley , Laurent Loinard

We present astrometric analysis of archival data of water masers in the star-forming region Sharpless 269 (S269) IRS 2w, observed with the VLBI Exploration of Radio Astrometry. An annual parallax of one of the bright maser features in this…

Astrophysics of Galaxies · Physics 2015-06-19 Yoshiharu Asaki , Hiroshi Imai , Andrej Mikhailovich Sobolev , Sergey Yurievich Parfenov

We present a study of the structure and dynamics of the star forming region B1-IRS (IRAS 03301+3057) using the properties of different molecules at high angular resolution (~4''). We have used VLA observations of NH3, CCS, and H2O masers at…

We report on a water maser survey towards a sample of 27 planetary nebulae (PNe) using the Robledo de Chavela and Medicina single-dish antennas, as well as the Very Large Array (VLA). Two detections have been obtained: the already known…

The paper describes a Space-VLBI observation of the 22 GHz H2O masers in the massive star-forming region G25.65+1.05, using the 10-m space antenna of Radioastron together with the ground-based VLBA array. Two observing epochs at the…

Astrophysics of Galaxies · Physics 2025-06-03 N. N. Shakhvorostova , A. V. Alakoz , I. E. Val'tts , I. D. Litovchenko

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

Using the Very Long Baseline Array and the European VLBI Network, we have observed 22.2 GHz H_2O and 1612 MHz OH masers in the "water fountain" source IRAS 18460-0151. The H_2O maser spectrum has a very wide line-of-sight velocity range…

Solar and Stellar Astrophysics · Physics 2015-06-16 Hiroshi Imai , Shuji Deguchi , Jun-ichi Nakashima , Sun Kwok , Philip J. Diamond

22 GHz water vapor emission was observed toward the central region of the spiral starburst galaxy NGC 253. Monitoring observations with the 100-m telescope at Effelsberg and measurements with the BnC array of the VLA reveal three distinct…

Astrophysics · Physics 2009-11-10 C. Henkel , A. Tarchi , K. M. Menten , A. B. Peck

To understand evolutionary and environmental effects during the formation of high-mass stars, we observed three regions of massive star formation at different evolutionary stages that reside in the same natal molecular cloud. Methods. The…

Solar and Stellar Astrophysics · Physics 2012-05-25 Y. Wang , H. Beuther , A. Bik , T. Vasyunina , Z. Jiang , E. Puga , H. Linz , J. A. Rodon , Th. Henning , M. Tamura

We present high angular resolution observations, using the Very Long Baseline Array (VLBA) of the NRAO, of the high-velocity water masers toward the "water-fountain" pre-planetary nebula, IRAS 16342-3814. The detailed structure of the water…

Astrophysics · Physics 2009-11-13 M. J Claussen , R. Sahai , M. R. Morris

We discovered new high-velocity components of H$_2$O maser emission in one of the "water fountain" sources, IRAS~18286$-$0959, which has been monitored using the Nobeyama 45 m telescope in the new FLASHING (Finest Legacy Acquisitions of…

Based on the long-term monitoring data of the water maser since 2019.0 to 2021.0 allowed us detecting in IRAS 16293-2422 two powerful phenomena lasted about year at radial velocities near 6 and 8 km s$^{-1}$. In both cases, powerful short…

Solar and Stellar Astrophysics · Physics 2022-08-03 A. E. Volvach , L. N. Volvach , M. G. Larionov

We present single-dish and VLBI observations of an outburst of water maser emission from the young binary system Haro 6-10. Haro 6-10 lies in the Taurus molecular cloud and contains a visible T Tauri star with an infrared companion 1.3"…

Solar and Stellar Astrophysics · Physics 2015-06-05 Bruce A. Wilking , Kevin B. Marvel , Mark J. Claussen , Bradley M. Gerling , Alwyn Wootten , Erika Gibb

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

Molecular outflows from very low-mass stars (VLMSs) and brown dwarfs (BDs) have been studied very little, and only a few objects have been directly imaged. Using VLT SINFONI K-band observations, we spatially resolved, for the first time,…

Solar and Stellar Astrophysics · Physics 2013-07-03 R. Garcia Lopez , A. Caratti o Garatti , G. Weigelt , B. Nisini , S. Antoniucci

We report Very Long Baseline Array (VLBA) observations of 43 GHz v=1, J=1-0 SiO masers in the circumstellar envelope of the M-type semi-regular variable star VX Sgr at 3 epochs during 1999 April-May. These high-resolution VLBA images reveal…

Astrophysics · Physics 2008-11-26 Xi Chen , Zhi-Qiang Shen , Hiroshi Imai , Ryuichi Kamohara

The NGC 1333 IRAS 4 region was observed in the 22 GHz H2O maser line with an angular resolution of about 0.08 arcseconds. Two groups of masers were detected, one near IRAS 4A and the other near BI. Among the eight maser spots detected near…

Astrophysics · Physics 2009-11-13 Geumsook Park , Minho Choi

We report the discovery of maser emission in the two lowest rotational transitions of CS toward the high-mass protostar W51 e2e with ALMA and the JVLA. The masers from CS J=1-0 and J=2-1 are neither spatially nor spectrally coincident (they…

Astrophysics of Galaxies · Physics 2020-01-08 Adam Ginsburg , Ciriaco Goddi