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Related papers: Optimizing helical disc dynamo

200 papers

Most large scale dynamo research for astrophysical rotators focuses on interior flow driven helical dynamos (FDHDs), but larger scale coronal fields most directly influence observations. It is thus important to understand the relationship…

Astrophysics · Physics 2008-11-26 Eric G. Blackman

A possible polar-ring debris disc, the dynamics of which can be described by the outer hierarchical restricted three-body problem, has been detected in 99 Herculis. An empirical formula on the minimum radius beyond which test particles in…

Earth and Planetary Astrophysics · Physics 2023-08-02 Ying Wang , Wei Sun , Ji-lin Zhou , Ming Yang , Fu-yao Liu

ALMA has revealed that the millimetre dust structures of protoplanetary discs are extremely diverse. It has been proposed that the strength of H$_2$O emission in the inner disc particularly depends on the influx of icy pebbles from the…

We present the results of global 3-D MHD simulations of stratified and turbulent protoplanetary disc models. The aim of this work is to develop thin disc models capable of sustaining turbulence for long run times, which can be used for…

Astrophysics · Physics 2009-11-11 Sebastien Fromang , Richard P. Nelson

Resolved debris disc images can exhibit a range of radial and azimuthal structures, including gaps and rings, which can result from planetary companions shaping the disc by their gravitational influence. Currently there are no tools…

Earth and Planetary Astrophysics · Physics 2016-02-17 E. Thilliez , S. T. Maddison

Magnetic helicity fluxes in turbulently driven alpha^2 dynamos are studied to demonstrate their ability to alleviate catastrophic quenching. A one-dimensional mean-field formalism is used to achieve magnetic Reynolds numbers of the order of…

Solar and Stellar Astrophysics · Physics 2012-07-17 Simon Candelaresi , Axel Brandenburg

HD141569 is a pre-main sequence star with a disc uniquely placed between protoplanetary and debris discs, similar to the older `hybrid' type discs. This work aims to place the mass and spatial structure of the disc midplane in the context…

Earth and Planetary Astrophysics · Physics 2018-07-25 James Miley , Olja Panic , Mark Wyatt , Grant Kennedy

We present results from the first population synthesis study of protostellar discs. We analyse the evolution and properties of a large sample of protostellar discs formed in a radiation hydrodynamical simulation of star cluster formation.…

Solar and Stellar Astrophysics · Physics 2018-01-25 Matthew R. Bate

The rapidly emerging technology of high-temperature superconductors (HTS) opens new opportunities for the development of non-planar non-insulated HTS magnets. This type of HTS magnet offers attractive features via its simplicity,…

Accelerator Physics · Physics 2020-10-28 Carlos Paz-Soldan

The problem of a cylinder of mass m and radius r, with its center of mass out of the cylinder axis, rolling on an incline that makes an angle with respect to the horizontal is analyzed. The equation of motion is partially solved to obtain…

Popular Physics · Physics 2013-05-07 R. W. Gómez , J. J. Hernández-Gómez , V. Marquina

We investigate accretion onto a central star, with the size, rotation rate, and magnetic dipole of a young stellar object, to study the flow pattern (velocity and density) of the fluid within and outside of the disc. We perform resistive…

Solar and Stellar Astrophysics · Physics 2023-06-14 R. Mishra , M. Čemeljić , W. Kluźniak

The magnetic field in Hall plasmas is frozen in the electron component and is advected not only with the plasma motion but also with the electrical current flow. Its coupling with the plasma may be not as strong as characteristic of the MHD…

Astrophysics · Physics 2009-11-06 L. I. Rudakov

Motivated by relativistic materials, we develop a numerical scheme to support existing or state new conjectures in the spectral optimisation of eigenvalues of the Dirac operator, subject to infinite-mass boundary conditions. We study the…

Optimization and Control · Mathematics 2025-02-05 Pedro R. S. Antunes , Francisco Bento , David Krejcirik

We report Very Large Array observations at 7 mm, 9 mm, and 3 cm toward the pre-transitional disk of the Herbig Ae star HD 169142. These observations have allowed us to study the mm emission of this disk with the highest angular resolution…

The stellar disc is the dominant luminous component of the Milky Way (MW). Although our understanding of its structure is rapidly expanding due to advances in large-scale stellar surveys, our picture of the MW disc remains substantially…

We calculate the magnetization of the helical metallic surface states of a topological insulator. We account for the presence of a small sub-dominant Schr{\"o}dinger piece in the Hamiltonian in addition to the dominant Dirac contribution.…

Mesoscale and Nanoscale Physics · Physics 2014-12-01 Calvin J. Tabert , J. P. Carbotte

Understanding the numerical dependencies that act on the galactic dynamo is a crucial step in determining what resolution and what conditions are required to properly capture the magnetic fields observed in galaxies. Here, we present an…

Astrophysics of Galaxies · Physics 2023-05-03 Robert Wissing , Sijing Shen

Context. A crucial step in the numerical investigation of small-scale dynamos in the solar atmosphere consists of an accurate determination of the magnetic Prandtl number, Prm, stemming from radiative magneto-hydrodynamic (MHD) simulations.…

Solar and Stellar Astrophysics · Physics 2022-04-27 Fabio Riva , Oskar Steiner

This work introduces the design analysis simulation and a standard MEMS fabrication process for a three dimensional microcoil with a magnetic core and a digital switch configuration using a completely integrated fully MEMS compatible…

Systems and Control · Electrical Eng. & Systems 2022-12-21 Abdelhameed Sharaf , S. M. Eladl , A. Nasr , Mohamed Serry

We extend the model of King et al. (2004) for variability in black hole accretion discs, by taking proper account of the thermal properties of the disc. Because the degree of variability in the King et al. (2004) model depends sensitively…

Astrophysics · Physics 2009-11-11 M. Mayer , J. E. Pringle