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Related papers: Extragalactic Zeeman Detections in OH Megamasers

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We aim to characterise the small-scale magnetic fields for a sample of 16 Sun-like stars and investigate the capabilities of the newly upgraded near-infrared (NIR) instrument CRIRES$^+$ at the VLT in the context of small-scale magnetic…

Context. Observations of Zeeman split spectral lines represent an important approach to derive the structure and strength of magnetic fields in molecular clouds. In contrast to the uncertainty of the spectral line observation itself, the…

Astrophysics of Galaxies · Physics 2017-05-10 R. Brauer , S. Wolf , S. Reissl , F. Ober

We present VLBA observations of 1667 MHz OH maser emission from the massive star formation region G5.89-0.39. The observations were phase referenced allowing the absolute positions of the masers to be obtained. The 1667 MHz masers have…

Astrophysics · Physics 2008-11-26 D. P. Stark , W. M. Goss , E. Churchwell , V. L. Fish , I. M. Hoffman

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

Aims: We have observed the 6030 and 6035 MHz transitions of OH in high-mass star-forming regions to obtain magnetic field estimates in both maser emission and absorption. Methods: Observations were taken with the Effelsberg 100 m telescope.…

Astrophysics · Physics 2009-11-11 Vincent L. Fish , Mark J. Reid , Karl M. Menten , Thushara Pillai

Context. Recent high angular resolution polarimetric continuum observations of circumstellar disks provide new insights into their magnetic field. However, direct constraints are limited to the plane of sky component of the magnetic field.…

Solar and Stellar Astrophysics · Physics 2017-11-22 R. Brauer , S. Wolf , M. Flock

Using the Very Long Baseline Array (VLBA) we performed a high resolution OH maser survey in Galactic star-forming regions (SFRs). We observed all the ground state spectral lines: the main lines at 1665 and 1667 MHz and the satellite lines…

Solar and Stellar Astrophysics · Physics 2016-03-28 A. E. Ruiz-Velasco , D. Felli , V. Migenes , B. K. Wiggins

M-type stars exhibit strong magnetic fields towards decreasing effective temperatures. The measurement of these fields is complicated due to missing indicators. Molecular FeH lines provide an excellent means to determine magnetic field…

Solar and Stellar Astrophysics · Physics 2010-11-30 Sebastian Wende , Ansgar Reiners , Andreas Seifahrt , Denis Shulyak , Oleg Kochukhov

We present observations of the Zeeman effect in OH thermal absorption main lines at 1665 and 1667 MHz taken with the Very Large Array (VLA) toward the star forming region S88B. The OH absorption profiles toward this source are complicated,…

Astrophysics of Galaxies · Physics 2015-06-15 A. P. Sarma , C. L. Brogan , T. L. Bourke , M. Eftimova , T. H. Troland

We report the first detection of circular polarization in 4.7 GHz excited OH masers in star-forming regions made using full Stokes measurements with the Green Bank 100m telescope. The Zeeman shift between the two circular components…

Astrophysics of Galaxies · Physics 2025-08-08 Derck P Smits , Paul Fallon

Although significant progress has been achieved in recent surveys of the magnetism in massive stars, the origin of the detected magnetic fields remains to be the least understood topic in their studies. We present an analysis of 61…

Solar and Stellar Astrophysics · Physics 2023-04-05 S. Hubrig , S. P. Jarvinen , I. Ilyin , M. Schöller , R. Jayaraman

We report on the observation of the 36 GHz methanol maser line in the star forming region DR21W to accurately measure the Zeeman effect. The reported Zeeman signature by Fish et al. (2011) became suspicious after an instrumental effect was…

Astrophysics of Galaxies · Physics 2015-06-05 E. Momjian , L. O. Sjouwerman , V. L. Fish

Direct measurements of magnetic fields in low-mass stars of spectral class M have become available during the last years. This contribution summarizes the data available on direct magnetic measurements in M dwarfs from Zeeman analysis in…

Solar and Stellar Astrophysics · Physics 2009-11-13 Ansgar Reiners

We report the detection of the Zeeman effect in the 44 GHz Class I methanol maser line toward the star forming region DR21(OH). In a 219 Jy/beam maser centered at an LSR velocity of 0.83 km s$^{-1}$, we find a 20-$\sigma$ detection of…

Astrophysics of Galaxies · Physics 2017-01-18 E. Momjian , A. P. Sarma

Several new main line OH masers have been detected in the nearby starburst galaxy M82. Eight masers have been detected to 5 sigma, six of which are new detections. Observations covering both the 1665 and 1667 MHz lines with both the Very…

Astrophysics · Physics 2007-05-23 M. K. Argo , A. Pedlar , T. W. B. Muxlow , R. J. Beswick , S. Aalto , K. Wills , R. Booth

Magnetic fields play a pivotal role in the physics of interstellar medium in galaxies, but there are few observational constraints on how they evolve across cosmic time. Spatially resolved synchrotron polarization maps at radio wavelengths…

Astrophysics of Galaxies · Physics 2017-08-30 S. A. Mao , C. Carilli , B. M. Gaensler , O. Wucknitz , C. Keeton , A. Basu , R. Beck , P. P. Kronberg , E. Zweibel

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 present data of proper motions of OH masers in the massive star-forming regions ON 1, K3-50, and W51 Main/South. OH maser motions in ON 1 are consistent with expansion at approximately 5 km/s, likely tracing the expanding ultracompact H…

Astrophysics · Physics 2009-11-13 Vincent L. Fish , Mark J. Reid

Both magnetic fields and photospheric/atmospheric dynamics can be involved in triggering the important mass loss observed in evolved cool stars. Previous works have revealed that these objects exhibit a magnetic field extending beyond their…

Solar and Stellar Astrophysics · Physics 2024-08-14 L. Marinho , F. Herpin , H. Wiesemeyer , A. López Ariste , A. Baudry , A. Asensio Ramos , A. Lèbre , P. Mathias , M. Montargès

We present full-polarization VLBA maps of the ground-state, main-line, 2 Pi 3/2, J = 3/2 OH masers in 18 Galactic massive star-forming regions. This is the first large polarization survey of interstellar hydroxyl masers at VLBI resolution.…

Astrophysics · Physics 2009-11-11 Vincent L. Fish , Mark J. Reid , Alice L. Argon , Xing-Wu Zheng