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Related papers: Modelling the molecular Zeeman effect in M-dwarfs:…

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Magnetic white dwarfs with field strengths below 10 MG are easy to recognise since the Zeeman splitting of spectral lines appears proportional to the magnetic field strength. For fields $\geq 100$ MG, however, transition wavelengths become…

Solar and Stellar Astrophysics · Physics 2023-01-25 Mark A. Hollands , Stella Stopkowicz , Marios-Petros Kitsaras , Florian Hampe , Simon Blaschke , J. J. Hermes

We report first results on a method aimed at simultaneously characterising atmospheric parameters and magnetic properties of M dwarfs from high-resolution nIR spectra recorded with SPIRou in the framework of the SPIRou Legacy Survey. Our…

Solar and Stellar Astrophysics · Physics 2023-03-29 P. I. Cristofari , J. -F. Donati , C. P. Folsom , T. Masseron , P. Fouqué , C. Moutou , E. Artigau , A. Carmona , P. Petit , X. Delfosse , E. Martioli

We present synthetic FeH band spectra in the z-filter range for several M-dwarf models with logg=3.0-5.0 [cgs] and Teff=2800K -3450K. Our aim is to characterize convective velocities in M-dwarfs and to give a rough estimate of the range in…

Astrophysics · Physics 2009-11-13 S. Wende , A. Reiners , H. G. Ludwig

(Edited for length) The Zeeman effect is the only observational technique available to measure directly the strength of magnetic fields in regions of star formation. We review the physics of the Zeeman effect and its practical use in both…

Astrophysics of Galaxies · Physics 2019-11-15 Richard M. Crutcher , Athol J. Kemball

We demonstrate that the combination of Zeeman, polarimetry and ion-to-neutral molecular line width ratio measurements permits the determination of the magnitude and orientation of the magnetic field in the weakly ionized parts of molecular…

The topic of magnetic field diagnostics with the Zeeman effect is currently vividly discussed. There are some testable inversion codes available to the spectropolarimetry community and their application allowed for a better understanding of…

Solar and Stellar Astrophysics · Physics 2016-11-29 M. Derouich

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

To obtain a better statistics on the occurrence of magnetism among white dwarfs, we searched the spectra of the hydrogen atmosphere white dwarf stars (DAs) in the Data Release 7 of the Sloan Digital Sky Survey (SDSS) for Zeeman splittings…

The currently most viable methods to estimate magnetic field strengths in molecular cloud cores are Zeeman measurements and the Chandrasekhar-Fermi (CF) method. The CF-method estimates magnetic field strengths from polarimetry and relies on…

Astrophysics · Physics 2007-05-23 F. Heitsch , P. S. Li

We present a new magnetic-atmosphere model code for obtaining synthetic spectral fluxes of hydrogen-rich magnetic white dwarfs. To date, observed spectra have been analyzed with models that neglect the magnetic field's effects on the atomic…

Solar and Stellar Astrophysics · Physics 2024-07-17 Matías Vera-Rueda , René D. Rohrmann

The purpose of the SOLIS Zeemanfit Code is to provide a straight-forward, easily checked measure of the total magnetic-field strength in the high-strength umbral regions of the solar disk. In the highest-strength regions, the Zeeman…

Solar and Stellar Astrophysics · Physics 2016-06-17 Anna L. H. Hughes , Jack Harvey , Andrew R. Marble , Alexei A. Pevtsov

Zeeman observations provide the only direct probe of line-of-sight (LOS) magnetic fields in the interstellar medium. To evaluate their accuracy and limitations, we generate synthetic HI Zeeman spectra from magnetohydrodynamic simulations…

Astrophysics of Galaxies · Physics 2026-02-24 Duo Xu , Peter Martin , Stella Offner , Robert Gutermuth , Michael Grudic , Joshua Speagle

The measurement of Zeeman splitting in spectral lines---both in emission and absorption---can provide direct estimates of the magnetic field strength and direction in atomic and molecular clouds, both in our own Milky Way and in external…

Magnetic fields are an important ingredient to cool star physics, and there is great interest in measuring fields and their geometry in order to understand stellar dynamos and their influence on star formation and stellar evolution. During…

Solar and Stellar Astrophysics · Physics 2015-03-17 Ansgar Reiners

Magnetic fields have been detected in several hundred white dwarfs, with strengths ranging from a few kG to several hundred MG. Only a few of the known fields have a mean magnetic field modulus below about 1 MG. We are searching for new…

Solar and Stellar Astrophysics · Physics 2016-06-29 J. D. Landstreet , S. Bagnulo , A. Martin , G. Valyavin

A spectroscopic survey of previously-unstudied Luyten Half Second proper motion stars has resulted in the discoveries of two new cool magnetic white dwarfs. One (LHS 2273) is a routine DA star, T= 6,500K, with Zeeman-split H alpha and H…

Astrophysics · Physics 2009-10-31 I. Neill Reid , James Liebert , Gary D. Schmidt

We present the results of an extensive Arecibo observational survey of magnetic field strengths in the inter-core regions of molecular clouds to determine their role in the evolution and collapse of molecular clouds as a whole. Sensitive 18…

Astrophysics of Galaxies · Physics 2019-10-16 K. L. Thompson , T. H. Troland , C. Heiles

The solar photospheric magnetic field is highly structured owing to its interaction with the convective flows. Its local structure has a strong influence on the profiles of spectral lines not only by virtue of the Zeeman effect, but also…

Solar and Stellar Astrophysics · Physics 2014-08-13 Benjamin Beeck , Manfred Schüssler , Ansgar Reiners

We analyze the effects of an applied magnetic field on the phase diagram of a weakly-correlated electron system with imperfect nesting. The Hamiltonian under study describes two bands: electron and hole ones. Both bands have spherical Fermi…

Strongly Correlated Electrons · Physics 2017-01-19 A. O. Sboychakov , A. L. Rakhmanov , K. I. Kugel , A. V. Rozhkov , Franco Nori

Measurements of interplanetary magnetic fields have long relied on spacecraft measurements, which provide only in-situ sampling and therefore cannot capture the global magnetic structure. Faraday rotation of radio signals extends in-situ…

Space Physics · Physics 2026-05-28 Chuanpeng Hou , Huirong Yan , Siqi Zhao