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Related papers: Magnetic fields during primordial star formation

200 papers

It is widely believed that primordial magnetic fields are dramatically diluted by the expansion of the universe. As a result, cosmological magnetic fields with residual strengths of astrophysical relevance are generally sought by going…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 John D. Barrow , Christos G. Tsagas

The interstellar medium (ISM) of our Galaxy is magnetized, compressible and turbulent, influencing many key ISM properties, like star formation, cosmic ray transport, and metal and phase mixing. Yet, basic statistics describing…

Astrophysics of Galaxies · Physics 2025-05-15 James R. Beattie , Christoph Federrath , Ralf S. Klessen , Salvatore Cielo , Amitava Bhattacharjee

We present simulations of collapsing filaments studying the impact of turbulence and magnetic field morphologies on their evolution and star formation properties. We vary the mass per unit length of the filaments as well as the orientation…

Astrophysics of Galaxies · Physics 2015-08-06 D. Seifried , S. Walch

Accretion disks in Active Galactic Nuclei (AGN) are predicted to become gravitationally unstable substantially interior to the black hole's sphere of influence, at radii where the disk is simultaneously unstable to the magnetorotational…

High Energy Astrophysical Phenomena · Physics 2025-07-30 Tsun Hin Navin Tsung , Mitchell C. Begelman , Philip J. Armitage , Yan-Fei Jiang , Hannalore J. Gerling-Dunsmore

The growth and saturation of magnetic field in conducting turbulent media with large magnetic Prandtl numbers are investigated. This regime is very common in low-density hot astrophysical plasmas. During the early (kinematic) stage, weak…

Astrophysics · Physics 2009-11-07 A. A. Schekochihin , S. C. Cowley , G. W. Hammett , J. L. Maron , J. C. McWilliams

[Abridged] Theoretical and numerical studies of star formation have shown that magnetic field (B) has a strong influence on both disk formation and fragmentation; even a relatively low B can prevent these processes. However, very few…

Solar and Stellar Astrophysics · Physics 2015-06-12 Marc Joos , Patrick Hennebelle , Andrea Ciardi , Sebastien Fromang

We point out that the lower bound on the primordial magnetic field required to seed the galactic dynamo is significantly relaxed in an open universe or in a universe with a positive cosmological constant. It is shown that, for reasonable…

Astrophysics · Physics 2008-11-26 Anne-Christine Davis , Matthew Lilley , Ola Tornkvist

We argue that the radiative zone above the iron core in pre-collapse cores of massive stars can store strong magnetic fields. To reach this conclusion we use the stellar evolutionary code MESA to simulate the evolution of two stellar models…

High Energy Astrophysical Phenomena · Physics 2019-04-10 Inbal Peres , Efrat Sabach , Noam Soker

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

During common envelope evolution, an initially weak magnetic field may undergo amplification by interacting with spiral density waves and turbulence generated in the stellar envelope by the inspiralling companion. Using 3D…

Solar and Stellar Astrophysics · Physics 2024-03-22 Damien Gagnier , Ondrej Pejcha

We develop an analytical model to follow the cosmological evolution of magnetic fields in disk galaxies. Our assumption is that fields are amplified from a small seed field via magnetohydrodynamical (MHD) turbulence. We further assume that…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Stanislav Shabala , James M. G. Mead , Paul Alexander

We study the effects of magnetic fields and rotation on the core collapse of a star of an initial mass of M = 20 solar masses using axisymmetric simulations coupling special relativistic magnetohydrodynamics, an approximately relativistic…

High Energy Astrophysical Phenomena · Physics 2018-06-26 M. Obergaulinger , O. Just , M. Á. Aloy

We study prospects of constraining the primordial magnetic field (PMF) and its evolution during the dark ages and cosmic dawn in light of EDGES 21-cm signal. Our analysis has been carried out on a `colder IGM' background which is one of the…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-13 Ankita Bera , Kanan K. Datta , Saumyadip Samui

The strengths of magnetic fields in interstellar gas clouds are obtained through observations of the circular polarization of spectral line radiation. Irregularities in this magnetic field may be present due to turbulence, waves or perhaps…

Astrophysics · Physics 2009-10-31 W. D. Watson , D. S. Wiebe , R. M. Crutcher

Using magnetohydrodynamic (MHD) adaptive mesh refinement simulations, we study the formation and early evolution of disk galaxies with a magnetized interstellar medium. For a $10^{10}$ \msun halo with initial NFW dark matter and gas…

Astrophysics · Physics 2009-04-17 Peng Wang , Tom Abel

The nature and origin of turbulence and magnetic fields in the intergalactic space are important problems that are yet to be understood. We propose a scenario in which turbulent flow motions are induced via the cascade of the vorticity…

Astrophysics · Physics 2009-11-13 Dongsu Ryu , Hyesung Kang , Jungyeon Cho , Santabrata Das

Small-scale dynamos play important roles in modern astrophysics, especially on Galactic and extragalactic scales. Owing to dynamo action, purely hydrodynamic Kolmogorov turbulence hardly exists and is often replaced by hydromagnetic…

Astrophysics of Galaxies · Physics 2022-12-20 A. Brandenburg , I. Rogachevskii , J. Schober

Fermi acceleration can take place at ultra-relativistic shock waves if the upstream or downstream magnetic field has been remodeled so that most of the magnetic power lies on short spatial scales. The relevant conditions under which Fermi…

Astrophysics · Physics 2009-11-13 Guy Pelletier , Martin Lemoine , Alexandre Marcowith

Based on the set of nonlinear coupling equations describing the interaction of the high-frequency field, the self-generated magnetic field and the ion-acoustic field, the dispersion relation for the circular magnetic field is obtained. The…

Plasma Physics · Physics 2022-10-31 X. L. Liu , X. Q. Li

(abridged) We investigate the possibility to recognize the magnetic field structures in nearby galaxies and to test the cosmological evolution of their large- and small-scale magnetic fields with the SKA and its precursors. We estimate the…

Cosmology and Nongalactic Astrophysics · Physics 2010-02-18 T. G. Arshakian , R. Stepanov , R. Beck , M. Krause , D. Sokoloff , P. Frick