Galactic magnetic X fields
| Autor: | R. N. Henriksen |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: | |
| Popis: | Our aim in this note is to compare a recent explanation of the galactic X pattern in Faraday Rotation (XRM), to that produced by the advection part of the classical dynamo.We find that the characteristic X magnetic field polarization in the plane of the sky, found in edge-on spiral galaxies, can develop magnetohydromagnetically from an initial disc magnetic field combined with wind and rotation. The Rotation Measure develops a corresponding X distribution in sign, but this distribution is not a `universal' behaviour because it depends primarily on the velocity field. We use Cauchy evolution of an initial magnetic field to find the field at some later time and place. A `battery' mechanism that requires current to always flow out of a galaxy has been recently suggested, which contrasts with the conclusions of this paper. Either explanation has significant consequences for the structure of a spiral galaxy. If the battery mechanism applies then we have a new method of producing magnetic field independent of the traditional dynamo. If however the flow mechanism applies; then constraints concerning the presence and nature of a galactic wind, together with the signature of the mean radial magnetic field, can be inferred. 6 pages four figures; accepted December 9,2021 |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|