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Related papers: OH and H2O maser variations in W33B

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Results of observations of the maser sources toward the W33C region (G12.8-0.2) carried out on the 22-m radio telescope of the Pushchino Radio Astronomy Observatory in the 1.35-cm H2O line and on the Large radio telescope in Nancay (France)…

Astrophysics of Galaxies · Physics 2015-06-11 P. Colom , E. E. Lekht , M. I. Pashchenko , G. M. Rudnitskij

Results of monitoring the H$_2$O and OH masers in W44C, located near the cometary HII region G34.3+0.15, are reported. Observations in the water-vapor line at $\lambda = 1.35$ cm were carried out on the 22-meter radio telescope of the…

Astrophysics of Galaxies · Physics 2011-11-22 E. E. Lekht , M. I. Pashchenko , G. M. Rudnitskii

The 1612 and 1667 MHz OH maser lines have been measured in all four Stokes parameters in 47 proto-planetary nebula (PPN) candidates. Out of 42 objects detected, 40 and 34 are 1612 and 1667 MHz emitters, respectively. The spectral extent of…

Astrophysics · Physics 2009-11-10 M. Szymczak , E. Gerard

Context: Ground-state OH maser emission from late-type stars is usually polarized and remains a powerful probe of the magnetic field structure in the outer regions of circumstellar envelopes if observed with high angular and spectral…

Astrophysics of Galaxies · Physics 2011-10-11 Paweł Wolak , Marian Szymczak , Eric Gérard

High-resolution VLA observations of 1720 MHz OH maser emission from Sgr A East and the circumnuclear disk with spatial and spectral resolutions of $\approx$ 2\dasec5 $\times$ 1\dasec3 and 0.27 \kms are reported. This follow-up observational…

Astrophysics · Physics 2009-10-30 F. Yusef-Zadeh , D. A. Roberts , W. M. Goss , D. A. Frail , A. J. Green

We present a survey of OH maser emission towards a sample of high mass protostellar objects made using the Nancay and GBT telescopes.OH maser emission was detected towards 63 objects with 36 new detections. There are 56 star-forming regions…

Astrophysics · Physics 2009-11-13 K. A. Edris , G. A. Fuller , R. J . Cohen

We use unpublished and published VLBI results to investigate the geometry and the statistical properties of the velocity field traced by H2O masers in five galactic regions of star formation -- Sgr B2(M), W49N, W51(MAIN), W51N, and W3(OH).…

Astrophysics · Physics 2009-11-07 V. Strelnitski , J. Alexander , S. Gezari , B. P. Holder , J. M. Moran , M. J. Reid

We present MERLIN observations of OH, water and methanol masers towards the young high mass stellar object IRAS 20126+4104. Emission from the 1665-MHz OH, 22-GHz H_2O and 6.7-GHz CH_3OH masers is detected and all originates very close to…

Astrophysics of Galaxies · Physics 2011-07-05 K. A. Edris , G. A. Fuller , R. J. Cohen , S. Etoka

From targeted observations of ground-state OH masers towards 702 Multibeam (MMB) survey 6.7-GHz methanol masers, between Galactic longitudes 186$^{\circ}$ through the Galactic centre to 20$^{\circ}$, made as part of the `MAGMO' project, we…

Astrophysics of Galaxies · Physics 2020-01-29 C. S. Ogbodo , J. A. Green , J. R. Dawson , S. L. Breen , S. A. Mao , N. M. McClure-Griffiths , T. Robishaw , L. Harvey-Smith , .

We present high angular resolution observations of OH maser emission towards the high-mass star forming region IRAS 06056+2131. The observations were carried out using the UK radio interferometer array, Multi-Element Radio Linked…

Solar and Stellar Astrophysics · Physics 2021-01-19 Mohamed Said darwish , Anita M. S. Richards , Sandra Etoka , Khaled Edris , Somaya Saad , Mohamed Beheary , Gary Fullar

Context. The high intensities and narrow bandwidths exhibited by some astronomical masers make them ideal tools for studying star-forming giant molecular clouds. The water maser transition $J_{K_{-1}K_{1}}=5_{32}-4_{41}$ at 620.701 GHz can…

Astrophysics of Galaxies · Physics 2014-09-05 S. C. Jones , M. Houde , M. Harwit , M. Kidger , A. Kraus , C. McCoey , A. Marston , G. Melnick , K. M. Menten , P. Morris , D. Teyssier , V. Tolls

MERLIN measurements of 1.6-GHz OH masers associated with Orion-BN/KL are presented, and the data are compared with data on other masers, molecular lines, compact radio continuum sources and infrared sources in the region. OH masers are…

Astrophysics · Physics 2009-11-11 R. J. Cohen , N. Gasipron , J. Meaburn , M. F. Graham

SiO maser emission occurs in the extended atmosphere of evolved stars and can be studied at high angular resolution. Very long baseline interferometry (VLBI) observations of Mira variables indicate that SiO masers are significantly linearly…

Solar and Stellar Astrophysics · Physics 2015-05-30 N. Amiri , W. H. T. Vlemmings , A. J. Kemball , H. J. van Langevelde

W75N(B) is a massive star-forming region that contains three radio continuum sources (VLA 1, VLA 2, and VLA 3), which are thought to be three massive young stellar objects at three different evolutionary stages. VLA 1 is the most evolved…

Solar and Stellar Astrophysics · Physics 2014-05-28 G. Surcis , W. H. T. Vlemmings , H. J. van Langevelde , C. Goddi , J. M. Torrelles , J. Cantó , S. Curiel , S. -W. Kim , J. -S. Kim

The excited states of OH masers detected in the environment of high-mass young stellar objects (HMYSOs) are important for improving our understanding of the physical conditions of these objects and also provide information about their…

Astrophysics of Galaxies · Physics 2020-10-14 M. Szymczak , P. Wolak , A. Bartkiewicz , M. Aramowicz , M. Durjasz

Context. Maser emission is a strong tool for studying high mass star forming regions and their evolutionary stages. OH masers in particular can trace the circumstellar material around protostars and determine their magnetic field strengths…

Astrophysics of Galaxies · Physics 2017-12-13 K. A. Edris , G. A. Fuller , S. Etoka , R. J. Cohen

We present results of a high resolution survey of OH masers in Galactic Star Forming Regions in order to study the maser emission and establish a list of suitable candidates for higher resolution instruments follow up. We used the Very Long…

Astrophysics · Physics 2007-05-23 A. E. Ruiz-Velasco , V. Migenes , V. Slysh , I. E. Val'tts

The southern maser site OH 300.969+1.147 has been studied using the Long Baseline Array of the Australia Telescope National Facility. The 1665- and 1667-MHz hydroxyl ground-state transitions were observed simultaneously. A series of maps…

Astrophysics of Galaxies · Physics 2015-05-13 J. L. Caswell , B. Hutawarakorn Kramer , J. E. Reynolds

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

Context. Water vapor emission at 22 GHz from masers associated with star-forming regions is highly variable. Aims. We present a database of up to 20 years of monitoring of a sample of 43 masers within star-forming regions. The sample covers…

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