A common origin of magnetism from planets to white dwarfs
| Autor: | Jordi Isern, Enrique García-Berro, Baybars Külebi, Pablo Lorén-Aguilar |
|---|---|
| Přispěvatelé: | Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. GAA - Grup d'Astronomia i Astrofísica |
| Rok vydání: | 2017 |
| Předmět: |
Solar System
Field (physics) Magnetism FOS: Physical sciences Astrophysics 010502 geochemistry & geophysics 01 natural sciences Camps magnètics solars Jupiter Planet 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics Stars - magnetic field 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics Solar and Stellar Astrophysics (astro-ph.SR) 0105 earth and related environmental sciences Physics Earth and Planetary Astrophysics (astro-ph.EP) Stars - interiors White dwarfs White dwarf Astronomy and Astrophysics Estels nans Stars Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science Física::Astronomia i astrofísica [Àrees temàtiques de la UPC] Stars--Magnetic fields Astrophysics::Earth and Planetary Astrophysics White dwarf stars Astrophysics - Earth and Planetary Astrophysics Dynamo |
| Zdroj: | UPCommons. Portal del coneixement obert de la UPC Universitat Politècnica de Catalunya (UPC) Recercat. Dipósit de la Recerca de Catalunya instname |
| DOI: | 10.48550/arxiv.1702.01813 |
| Popis: | 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 magnetic fields amplified during the course of the evolution of their progenitor stars, or are the result of binary interactions or, finally, they are produced by other internal physical mechanisms during the cooling of the white dwarf itself, remains a mystery. At sufficiently low temperatures white dwarfs crystallize. Upon solidification, phase separation of its main constituents, 12C and 16O, and of the impurities left by previous evolution occurs. This process leads to the formation of a Rayleigh-Taylor unstable liquid mantle on top of a solid core. This convective region, as it occurs in Solar System planets like the Earth and Jupiter, can produce a dynamo able to yield magnetic fields of strengths of up to 0.1 MG, thus providing a mechanism that could explain magnetism in single white dwarfs. Comment: The Astrophysical Journal Letters, 836:L28 (5pp), 2017 February 20 |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|