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The true nature of primordial magnetic fields (PMFs) and their role in the formation of galaxies still remains elusive. To shed light on these unknowns, we investigate their impact by varying two sets of properties: (i) accounting for the…

Astrophysics of Galaxies · Physics 2024-10-02 Mahsa Sanati , Sergio Martin-Alvarez , Jennifer Schober , Yves Revaz , Adrianne Slyz , Julien Devriendt

Magnetic fields in nearby, star-forming galaxies reveal both large-scale patterns and small-scale structures. A large-scale field reversal may exist in the Milky Way but no such reversals have been observed so far in external galaxies. The…

Astrophysics of Galaxies · Physics 2015-05-30 David Moss , Rodion Stepanov , Tigran Arshakian , Rainer Beck , Marita Krause , Dmitri Sokoloff

The origin and growth of magnetic fields in galaxies is still something of an enigma. It is generally assumed that seed fields are amplified over time through the dynamo effect, but there are few constraints on the timescale. It has…

Strong magnetic fields are observed in a substantial fraction of upper main sequence stars and white dwarfs. Many such stars are observed to exhibit photometric modulations as the magnetic poles rotate in and out of view, which could be a…

Solar and Stellar Astrophysics · Physics 2023-02-22 Jim Fuller , Stephane Mathis

Magnetic fields appear to be present in all galaxies and galaxy clusters. Recent measurements indicate that a weak magnetic field may be present even in the smooth low density intergalactic medium. One explanation for these observations is…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Smadar Naoz , Ramesh Narayan

The sample of white dwarfs included in the local 20 pc volume documents, fairly accurately, the total production of white dwarfs over roughly 10 Gyr of stellar evolution in this part of the Milky Way Galaxy. In this sample, we have been…

Solar and Stellar Astrophysics · Physics 2020-11-18 S. Bagnulo , J. D. Landstreet

We present maps of total magnetic field using 'equipartition' assumptions for five nearby normal galaxies at sub-kpc spatial resolution. The mean magnetic field is found to be ~11 \mu G. The field is strongest near the central regions where…

Astrophysics of Galaxies · Physics 2015-06-15 Aritra Basu , Subhashis Roy

The magnetic fields observed in the Milky~Way and nearby galaxies appear to be in equipartition with the turbulent, thermal, and cosmic ray energy densities, and hence are expected to be dynamically important. However, the origin of these…

Magnetic fields play a vital role in numerous astrophysical processes such as star formation and the interstellar medium. In particular, their role in the formation and evolution of galaxies is not well understood. This paper presents…

Astrophysics of Galaxies · Physics 2021-12-10 Huai-Hsuan Chiu , Ke-Jung Chen

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…

Astrophysics · Physics 2009-11-13 Tigran G. Arshakian , Rainer Beck , Marita Krause , Dmitry Sokoloff

The origin and the magnitude of the inter-galactic magnetic field is of primordial importance in the global picture of magnetic field evolution, as it is considered to be the missing link between galactic magnetic fields and cluster…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Yohan Dubois , Romain Teyssier

Very-high energy observations of blazars can be used to constrain the strength of the intergalactic magnetic field. A simplifying assumption which is often made is that of a magnetic field of constant strength composed by randomly oriented…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Chiara Caprini , Stefano Gabici

The magnetic white dwarfs (MWDs) are found either isolated or in interacting binaries. They divide into two groups: a high field group (0.1-1,000MegaGauss) comprising some 13% of all white dwarfs (WDs), and a low field group (B<0.1MG) whose…

Solar and Stellar Astrophysics · Physics 2020-01-29 Lilia Ferrario , D. T. Wickramasinghe , Adela Kawka

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…

Solar and Stellar Astrophysics · Physics 2015-05-30 D. Shulyak , A. Seifahrt , A. Reiners , O. Kochukhov , N. Piskunov

We investigate the previously unexplored role of magnetic fields in the formation of second-generation (SG) stars in proto-globular clusters (GCs) using 3D radiation-magnetohydrodynamical simulations. This study is based on the asymptotic…

Our theoretical and numerical analysis have suggested that for low-mass main sequences stars (of the spectral classes from M5 to G0) rotating much faster than the Sun, the generated large-scale magnetic field is caused by the mean-field…

Solar and Stellar Astrophysics · Physics 2024-04-19 N. Kleeorin , I. Rogachevskii , N. Safiullin , R. Gershberg , S. Porshnev

The Universe at present is highly magnetized, with fields of the order of a few 10^-5 G and coherence lengths larger than 10 kpc in typical galaxies like the Milky Way. We propose that the magnetic field was amplified to this values already…

Astrophysics of Galaxies · Physics 2015-06-17 Jennifer Schober , Dominik R. G. Schleicher , Ralf S. Klessen

Isolated magnetic white dwarfs have field strengths ranging from kilogauss to gigagauss. However, the origin of the magnetic field has not been hitherto elucidated. Whether these fields are fossil, hence the remnants of original weak…

Solar and Stellar Astrophysics · Physics 2017-02-22 Jordi Isern , Enrique García-Berro , Baybars Külebi , Pablo Lorén-Aguilar

We investigate the cosmological evolution of large- and small-scale magnetic fields in galaxies at high redshifts. Results from simulations of hierarchical structure formation cosmology provide a tool to develop an evolutionary model of…

Astrophysics · Physics 2009-11-13 Tigran G. Arshakian , Rainer Beck , Marita Krause , Dmitry Sokoloff

Spiral galaxies host dynamically important magnetic fields which can affect gas flows in the disks and halos. Total magnetic fields in spiral galaxies are strongest (up to 30 \muG) in the spiral arms where they are mostly turbulent or…

Astrophysics · Physics 2009-06-23 Rainer Beck