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相关论文: Seeking large-scale magnetic fields in a pure-disk…

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Magnetic fields play an important role in the formation and evolution of a galaxy, but it is challenging to measure them by observation. Here we study the Seyfert galaxy NGC 3627's magnetic field orientations measured from the synchrotron…

星系天体物理 · 物理学 2022-12-07 Mingrui Liu , Yue Hu , A. Lazarian , Siyao Xu , Marian Soida

The magnetic structure in the Galactic disk, the Galactic center and the Galactic halo can be delineated more clearly than ever before. In the Galactic disk, the magnetic structure has been revealed by starlight polarization within 2 or 3…

星系天体物理 · 物理学 2009-11-13 J. L. Han

Interstellar magnetic fields are strong: up to 25 muG in spiral arms and 40 muG in nuclear regions. In the spiral galaxy NGC 6946 the average magnetic energy density exceeds that of the thermal gas. Magnetic fields control the evolution of…

天体物理学 · 物理学 2017-01-25 Rainer Beck

Many magnetic white dwarfs exhibit a polarised spectrum that periodically varies as the star rotates because the magnetic field is not symmetric about the rotation axis. In this work, we report the discovery that while weakly magnetic white…

太阳与恒星天体物理 · 物理学 2024-11-18 S. Bagnulo , J. D. Landstreet

We present a model of the global magnetic field in the barred galaxy NGC 1365 based jointly on the large-scale velocity field of interstellar gas fitted to HI and CO observations of this galaxy and on mean-field dynamo theory. The aim of…

天体物理学 · 物理学 2009-11-13 D. Moss , A. P. Snodin , P. Englmaier , A. Shukurov , R. Beck , D. D. Sokoloff

Aims. We investigate the cosmological evolution of large- and small-scale magnetic fields in galaxies in the light of present models of formation and evolution of galaxies. Methods. We use the dynamo theory to derive the timescales of…

天体物理学 · 物理学 2009-11-13 Tigran G. Arshakian , Rainer Beck , Marita Krause , Dmitry Sokoloff

We present a new procedure to fit non-axisymmetric flow patterns to 2-D velocity maps of spiral galaxies. We concentrate on flows caused by bar-like or oval distortions to the total potential that may arise either from a non-axially…

天体物理学 · 物理学 2011-02-11 Kristine Spekkens , J. A. Sellwood

In several spiral galaxies that are observed face-on, large-scale ordered magnetic fields (the so-called magnetic arms) were found. One of the explanations was the action of the magnetic reconnection, which leads to a higher ordering of the…

星系天体物理 · 物理学 2022-09-14 M. Wezgowiec , R. Beck , M. Hanasz , M. Soida , M. Ehle , R. -J. Dettmar , M. Urbanik

Magnetic fields are widely observed in various astronomical contexts, yet much remains unknown about their significance across different systems and cosmic epochs. Our current knowledge of the evolution of magnetic fields is limited by…

星系天体物理 · 物理学 2024-12-04 Jianhang Chen , Enrique Lopez-Rodriguez , R. J. Ivison , James E. Geach , Simon Dye , Xiaohui Liu , George Bendo

Using a set of cosmological hydro-dynamical simulations, we constrained the properties of primordial magnetic fields by studying their impact on the formation and evolution of dwarf galaxies. We performed a large set of simulations (8 dark…

星系天体物理 · 物理学 2020-11-04 Mahsa Sanati , Yves Revaz , Jennifer Schober , Kerstin E. Kunze , Pascale Jablonka

We report the discovery of a coherent magnetic spiral structure within the nearby ringed Sab galaxy NGC 4736. High sensitivity radio polarimetric data obtained with the VLA at 8.46GHz and 4.86GHz show a distinct ring of total radio emission…

天体物理学 · 物理学 2009-11-13 Krzysztof T. Chyzy , Ronald J. Buta

Circular polarisation measurements of white dwarfs of various ages and spectral types are useful to understand the origin and evolution of the magnetic field in degenerate stars. In the latest stages of white dwarf evolution, when stars are…

太阳与恒星天体物理 · 物理学 2022-01-19 Andrei V. Berdyugin , Vilppu Piirola , Stefano Bagnulo , John D. Landstreet , Svetlana V. Berdyugina

Stellar dynamos generate magnetic fields that are of fundamental importance to the variability and evolution of Sun-like and low-mass stars, and for the development of their planetary systems. We report measurements of surface-average…

Observations of synchrotron radiation and the Faraday rotation of its polarized component allow us to investigate the magnetic properties of the diffuse interstellar medium in nearby galaxies, on scales down to roughly one hundred parsecs.…

宇宙学与河外天体物理 · 物理学 2011-04-14 Andrew Fletcher

The strength of the total magnetic field in our Milky Way from radio Zeeman and synchrotron measurements is about 6 muG near the Sun and several mG in dense clouds, pulsar wind nebulae, and filaments near the Galactic Center. Diffuse…

天体物理学 · 物理学 2009-11-13 Rainer Beck

The Andromeda Galaxy (M31) is the nearest grand-design spiral galaxy. Thus far most studies in the radio regime concentrated on the 10 kpc ring. The central region of M31 has significantly different properties than the outer parts: The star…

星系天体物理 · 物理学 2015-06-22 René Gießübel , Rainer Beck

Close M-dwarf binaries and higher multiples allow the investigation of rotational evolution and mean magnetic flux unbiased from scatter in inclination angle and age since the orientation of the spin axis of the components is most likely…

太阳与恒星天体物理 · 物理学 2015-05-30 D. Shulyak , A. Seifahrt , A. Reiners , O. Kochukhov , N. Piskunov

We study the mass distribution in the late-type dwarf galaxy NGC 2976 through stellar kinematics obtained with the VIRUS-P integral-field spectrograph and anisotropic Jeans models as a test of cosmological simulations and baryonic processes…

Many spiral galaxies host magnetic fields with energy densities comparable to those of the turbulent and thermal motions of their interstellar gas. However, quantitative comparison between magnetic field properties inferred from observation…

星系天体物理 · 物理学 2025-08-05 Rion Glenn Nazareth , Gayathri Santhosh , Luke Chamandy

NGC 2915 is a blue compact dwarf galaxy embedded in an extended, low surface brightness HI disk exhibiting a two-armed spiral structure and a central bar-like component. Commonly accepted mechanisms are unable to explain the existence of…

天体物理学 · 物理学 2009-11-07 F. S. Masset , M. Bureau