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Related papers: Parsec-scale magnetic fields in Arp 220

200 papers

We present the current results of a survey for OH megamasers (OHMs) underway at the Arecibo Observatory. The survey is 2/3 complete and has produced a high OHM detection rate (1 in 6) from a redshift-selected sample of IRAS galaxies. The…

Astrophysics · Physics 2007-05-23 Jeremy Darling , Riccardo Giovanelli

OH 1612 and 1667 MHz masers from the well known object OH127.8+0.0 were mon- itored in full-polarization mode over a period of 6.5 years and mapped with MERLIN at one epoch. The OH variability pattern of the star is typical of extremely…

Astrophysics of Galaxies · Physics 2013-02-11 P. Wolak , M. Szymczak , E. Gerard

Shock-induced H2O masers are important magnetic field tracers at very high density gas. Water masers are found in both high- and low-mass star-forming regions, acting as a powerful tool to compare magnetic field morphologies in both mass…

Astrophysics of Galaxies · Physics 2015-06-04 Felipe O. Alves , Wouter H. T. Vlemmings , Josep M. Girart , José M. Torrelles

The characterization of magnetic fields within molecular clouds is fundamental to understanding star formation processes. Accurately gauging the three-dimensional structure of these fields presents a challenge, as observational techniques…

Astrophysics of Galaxies · Physics 2024-11-18 Brandon Shane , Blakesley Burkhart , Laura Fissel , Susan E. Clark , Philip Mocz , Michael M. Foley

We present the analysis of the circular polarization, due to Zeeman splitting, of the water masers around a sample of late-type stars to determine the magnetic fields in their circumstellar envelopes. The magnetic field strengths in the…

Astrophysics · Physics 2007-05-23 W. H. T. Vlemmings , H. J. van Langevelde , P. J. Diamond

We present new, high angular resolution (~0.22") MERLIN observations of neutral hydrogen (HI) absorption and 21-cm radio continuum emission across the central ~900 parsecs of the ultraluminous infrared galaxy, Arp220. Spatially resolved HI…

Astrophysics · Physics 2009-11-06 C. G. Mundell , P Ferruit , A Pedlar

Arp220 is a nearby system in final stages of galaxy merger with powerful ongoing star-formation at and surrounding the two nuclei. Arp 220 was detected in HI absorption and OH Megamaser emission and later recognized as the nearest…

Astrophysics · Physics 2009-11-13 W. A. Baan

We present initial results of a project to measure mean longitudinal magnetic fields in a group of sdB/OB/O stars. The project was inspired by the discovery of three super-metal-rich sdOB stars, each having metals (e.g. Ti, V) enhanced by…

Astrophysics · Physics 2007-05-23 S. J. O'Toole , S. Jordan , S. Friedrich , U. Heber

Magnetic field investigations of Sun-like stars, using Zeeman splitting of non-polarised spectra, in the optical and H-band have found significantly different magnetic field strengths for the same stars, the cause of which is currently…

Astrophysical masers are widely used in star formation studies. In particular, they are valuable in investigations of high-mass star-forming regions that are difficult to observe at optical frequencies. We used multi-transition data to…

Solar and Stellar Astrophysics · Physics 2025-03-17 A. Kobak , A. Bartkiewicz , K. L. J. Rygl , A. M. S. Richards , M. Szymczak , P. Wolak

We present new VLA, MERLIN and VLBI images for the radio galaxy 3C 338, and the results of the monitoring of its arcsecond core flux density. Present high sensitivity observations allow us to investigate the radio structure of this source…

Astrophysics · Physics 2009-10-30 G. Giovannini , W. D. Cotton , L. Feretti , L. Lara , T. Venturi

We present the results of a new survey of 23 molecular clouds for the Zeeman effect in OH undertaken with the ATNF Parkes 64-m radio telescope and the NRAO Green Bank 43-m radio telescope. The Zeeman effect was clearly detected in the cloud…

Astrophysics · Physics 2009-11-06 Tyler L. Bourke , Philip C. Myers , Garry Robinson , A. R. Hyland

We have obtained accurate circular spectropolarimetric observations for a sample of Vega-like and Herbig Ae/Be stars with FORS1 at the VLT in an attempt to detect their magnetic fields. No magnetic field could be diagnosed in any Vega-like…

Astrophysics · Physics 2016-08-30 S. Hubrig , R. V. Yudin , M. Schoeller , M. A. Pogodin

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

Polarisation observations of masers in the circumstellar envelopes (CSEs) around Asymptotic Giant Branch (AGB) stars have revealed strong magnetic fields. However, masers probe only specific lines-of-sight through the CSE. Non-masing…

Solar and Stellar Astrophysics · Physics 2024-06-19 W. H. T. Vlemmings , B. Lankhaar , L. Velilla-Prieto

We present new Karl G. Jansky Very Large Array radio continuum images of the nuclei of Arp 220, the nearest ultra-luminous infrared galaxy. These images have both the angular resolution to study detailed morphologies of the two nuclei that…

We analyse new observations with the International Low Frequency Array (LOFAR) telescope, and archival data from the Multi-Element Radio Linked Interferometer Network (MERLIN) and the Karl G. Jansky Very Large Array (VLA). We model the…

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

The polarized emission of astrophysical masers, especially OH and methanol lines, is an effective tool to study the magnetic field in high-mass star-forming regions. The magnetic field strength measurement via the Zeeman effect of OH maser…

Astrophysics of Galaxies · Physics 2025-08-21 A. Kobak , G. Surcis , A. Bartkiewicz , W. H. T. Vlemmings , M. Szymczak

We report on the first space-VLBI observations of the OH masers in two main-line OH transitions at 1665 and 1667 MHz. The observations involved the space radio telescope on board the Japanese satellite HALCA and an array of ground radio…

Astrophysics · Physics 2007-05-23 V. I. Slysh , M. A. Voronkov , I. E. Val'tts , V. Migenes , K. M. Shibata , T. Umemoto