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We report 5-43 GHz radio observations of the CRL 2136 region at 0.6-6 arcsec resolution. We detect weak (mJy intensity) radio emission from the deeply embedded high-mass protostar IRS 1, which has an optically thick spectrum up to…

Astrophysics · Physics 2009-11-10 K. M. Menten , F. F. S. van der Tak

We present sub-arcsecond ($\theta\sim0.1^{\prime\prime}$) resolution VLA 1.3 cm continuum and 22.2 GHz H$_2$O maser observations toward 15 compact radio continuum sources with rising spectral index and 8 string-like radio continuum…

Solar and Stellar Astrophysics · Physics 2026-01-19 Tatiana M. Rodriguez , Peter Hofner , Emmanuel Momjian , Esteban D. Araya , Ananay Sethi , Viviana Rosero

We present results from a study of two luminous IRAS sources thought to be young massive star-forming regions and which have no previously detected radio continuum emission: IRAS 15596-5301 and IRAS 16272-4837. Our study incorporates…

Astrophysics · Physics 2007-05-23 K. J. Brooks , G. Garay , D. Mardones , R. P. Norris , M. G. Burton

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

Radio emission has been detected in a broad variety of stellar objects from all stages of stellar evolution. However, most of our knowledge originates from targeted observations of small samples, which are strongly biased to sources which…

Solar and Stellar Astrophysics · Physics 2015-10-07 G. Umana , C. Trigilio , T. M. O. Franzen , R. P. Norris , P. Leto , A. Ingallinera , C. S. Buemi , C. Agliozzo , F. Cavallaro , L. Cerrigone

The Australia Telescope Compact Array (ATCA) has been used to image class I methanol masers at 9.9, 25 (a series from J=2 to J=9), 84, 95 and 104 GHz located in the vicinity of IRAS 16547-4247 (G343.12-0.06), a luminous young stellar object…

We present the results of a 22GHz H2O maser survey toward a new sample of AGB and post-AGB star candidates. Most of the objects are selected for the first time based on the AKARI data, which have high flux sensitivity in the mid-infrared…

Solar and Stellar Astrophysics · Physics 2015-06-15 Bosco Yung , Jun-ichi Nakashima , Hiroshi Imai , Shuji Deguchi , Christian Henkel , Sun Kwok

We investigate which structures the 6.7 GHz methanol masers trace in the environment of high-mass protostar candidates by observing a homogenous sample of methanol masers selected from Torun surveys. We also probed their origins by looking…

Astrophysics of Galaxies · Physics 2015-05-13 A. Bartkiewicz , M. Szymczak , H. J. van Langevelde , A. M. S. Richards , Y. M. Pihlstrom

We performed a systematic 6.7 GHz Class \uppercase\expandafter{\romannumeral2} methanol maser survey using the Shanghai Tianma Radio Telescope toward targets selected from the all-sky \emph{Wide-Field Infrared Survey Explorer (WISE)} point…

Astrophysics of Galaxies · Physics 2019-04-30 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 , Zhiyuan Ren

A southern hemisphere survey of methanol emission sources in two millimeter wave transitions has been carried out using the ATNF Mopra millimetre telescope. Sixteen emission sources have been detected in the 3(1)-4(0)A+ transition of…

Astrophysics · Physics 2009-10-31 I. E. Valtts , S. P. Ellingsen , V. I. Slysh , S. V. Kalenskii , R. Otrupcek , M. A. Voronkov

The present paper focuses on the high-mass star-forming region G16.59-0.05. Methods: Using the VLBA and the EVN arrays, we conducted phase-referenced observations of the three most powerful maser species in G16.59-0.05: H2O at 22.2 GHz (4…

Astrophysics of Galaxies · Physics 2015-05-18 A. Sanna , L. Moscadelli , R. Cesaroni , A. Tarchi , R. S. Furuya , C. Goddi

We explored an efficient method to identify evolved stars with oxygen-rich envelopes in the late AGB or post-AGB phase of stellar evolution, which include a rare class of objects - the "water fountains". Our method considers the OH and H2O…

Solar and Stellar Astrophysics · Physics 2015-06-22 Bosco Yung , Jun-ichi Nakashima , Christian Henkel

We present the results of 22 GHz H_2O maser observations of a sample of 85 post-Asymptotic Giant Branch (post-AGB) candidate stars, selected on the basis of their OH 1612 MHz maser and far-infrared properties. All sources were observed with…

Astrophysics · Physics 2009-11-13 R. M. Deacon , J. M. Chapman , A. J. Green , M. N. Sevenster

The IRAS source, 19312+1950, exhibits SiO maser emission, which is predominantly detected in evolved stars enshrouded by a cold molecular envelope. In fact, the mojority of the observational properties of IRAS 19312+1950 is consistent with…

Solar and Stellar Astrophysics · Physics 2015-05-20 Jun-ichi Nakashima , Shuji Deguchi , Hiroshi Imai , Athol Kemball , B. M. Lewis

The study of infall motion helps us to understand the initial stages of star formation. In this paper, we use the IRAM 30-m telescope to make mapping observations of 24 infall sources confirmed in previous work. The lines we use to track…

Astrophysics of Galaxies · Physics 2021-12-08 Yang Yang , Zhibo Jiang , Zhiwei Chen , Yiping Ao , Shuling Yu

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

In this work we present a sensitive and systematic single-dish survey of CCS emission (complemented with ammonia observations) at 1 cm, toward a sample of low- and intermediate-mass young star forming regions known to harbor water maser…

Infrared Dark Clouds are expected to harbor sources in different, very young evolutionary stages. To better characterize these differences, we observed a sample of 43 massive Infrared Dark Clouds, originally selected as candidate high-mass…

Astrophysics · Physics 2019-08-19 H. Beuther , T. K. Sridharan

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

We present radio continuum observations at 7 mm made using the Very Large Array towards three massive star forming regions thought to be in very early stages of evolution selected from the sample of Sridharan et al. (2002). Emission was…

Astrophysics · Physics 2009-06-23 Guido Garay , Luis F. Rodriguez , Itziar de Gregorio-Monsalvo
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