Skip to main content Accessibility help
×
Hostname: page-component-848d4c4894-4hhp2 Total loading time: 0 Render date: 2024-05-24T20:13:13.467Z Has data issue: false hasContentIssue false

Turbulence and Magnetic Reconnection in the Interstellar Medium

Published online by Cambridge University Press:  04 August 2010

Ellen G. Zweibel
Affiliation:
JILA and Department of Astrophysics and Planetary Science, University of Colorado, Boulder, CO 80309, USA
Jose Franco
Affiliation:
Universidad Nacional Autónoma de México
Alberto Carraminana
Affiliation:
Instituto Nacional de Astrofisica, Optica y Electronica, Tonantzintla, Mexico
Get access

Summary

Magnetic reconnection is often assumed to occur at an enhanced rate in the interstellar medium because of the effects of small scale turbulence. This effect is not modelled directly in numerical simulations, but is accounted for by explicitly assuming the resistivity is large, or assuming that numerical resistivity mimics the effect of small scale turbulence. The effective resistivity really is large only if the field can rapidly reconnect. In this paper I discuss two physical mechanisms for fast magnetic reconnection in the interstellar medium: enhanced diffusion at stagnation points, and formation of current sheets.

Introduction

Numerical experiments are making important contributions to the study of turbulence in the interstellar medium (ISM). Since any numerical simulation is restricted in the range of spatial and temporal scales which it can describe, it is important to develop a prescription for treating the effects of turbulence at the smallest scales, which are generally omitted from this range. Although very little energy resides at the smallest scales, the small scale motions dramatically increase momentum and magnetic flux transport in the ISM, and can also produce rapid thermal and chemical mixing. The most common way to account for these subgridscale effects is to simply assume that the viscosity, electrical resistivity, and other transport coefficients are much larger than their molecular values. The difficult problem of justifying this approach and calculating the so-called eddy diffusivities has received more attention in the atmospheric and stellar turbulence communities than it has, so far, among interstellar turbulence theorists.

Type
Chapter
Information
Publisher: Cambridge University Press
Print publication year: 1999

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Save book to Kindle

To save this book to your Kindle, first ensure coreplatform@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Available formats
×

Save book to Dropbox

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.

Available formats
×

Save book to Google Drive

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.

Available formats
×