Skip to content Skip to navigation
University of Warwick
  • Study
  • |
  • Research
  • |
  • Business
  • |
  • Alumni
  • |
  • News
  • |
  • About

University of Warwick
Publications service & WRAP

Highlight your research

  • WRAP
    • Home
    • Search WRAP
    • Browse by Warwick Author
    • Browse WRAP by Year
    • Browse WRAP by Subject
    • Browse WRAP by Department
    • Browse WRAP by Funder
    • Browse Theses by Department
  • Publications Service
    • Home
    • Search Publications Service
    • Browse by Warwick Author
    • Browse Publications service by Year
    • Browse Publications service by Subject
    • Browse Publications service by Department
    • Browse Publications service by Funder
  • Help & Advice
University of Warwick

The Library

  • Login
  • Admin

Undamped transverse oscillations of coronal loops as a self-oscillatory process

Tools
- Tools
+ Tools

Nakariakov, V. M. (Valery M.), Anfinogentov, Sergey, Nisticò, Giuseppe and Lee, D. -H. (2016) Undamped transverse oscillations of coronal loops as a self-oscillatory process. Astronomy & Astrophysics, 591 . L5. doi:10.1051/0004-6361/201628850 ISSN 0004-6361.

[img] PDF
WRAP_aa28850-16.pdf - Published Version - Requires a PDF viewer.

Download (2861Kb)
[img] PDF
WRAP_9877890-px-180516-nakariakov_rev_onecolumn.pdf - Accepted Version
Embargoed item. Restricted access to Repository staff only - Requires a PDF viewer.

Download (2481Kb)
Official URL: http://dx.doi.org/10.1051/0004-6361/201628850

Request Changes to record.

Abstract

Context. Standing transverse oscillations of coronal loops are observed to operate in two regimes, the rapidly decaying large amplitude oscillations, and undamped small amplitude oscillations. In the latter regime the damping should be compensated by energy supply, which allows the loop to perform almost monochromatic oscillations with almost constant amplitude. Different loops oscillate with different periods. The oscillation amplitude does not show dependence on the loop length or the oscillation period.

Aims. We aim to develop a low-dimensional model explaining the undamped kink oscillations as a self-oscillatory process caused by the effect of negative friction. The source of energy is an external quasi-steady flow, e.g. supergranulation motions near the loop footpoints or external flows in the corona.

Methods. We demonstrate that the interaction of a quasi-steady flow with a loop can be described by a Rayleigh oscillator equation that is a nonlinear ordinary differential equation, with the damping and resonant terms determined empirically. Results. Low-amplitude self-oscillatory solutions to the Rayleigh oscillator equation are harmonic signals of constant amplitude, which is consistent with the observed properties of undamped kink oscillations. The period of self-oscillations is determined by the frequency of the kink mode. The damping by dissipation and mode conversion is compensated by the continuous energy deposition at the frequency of the natural oscillation.

Conclusions. We propose that undamped kink oscillations of coronal loops may be caused by the interaction of the loops with quasi-steady flows, and hence are self-oscillations, in analogy with producing a tune by a stick moving across a violin string.

Item Type: Journal Article
Alternative Title:
Divisions: Faculty of Science, Engineering and Medicine > Science > Physics
Journal or Publication Title: Astronomy & Astrophysics
Publisher: EDP Sciences
ISSN: 0004-6361
Official Date: 20 June 2016
Dates:
DateEvent
20 June 2016Published
18 May 2016Accepted
4 May 2016Submitted
Volume: 591
Number of Pages: 4
Article Number: L5
DOI: 10.1051/0004-6361/201628850
Status: Peer Reviewed
Publication Status: Published
Access rights to Published version: Open Access (Creative Commons)
Date of first compliant deposit: 20 May 2016
Date of first compliant Open Access: 22 August 2016
Adapted As:
Related URLs:
  • Publisher

Request changes or add full text files to a record

Repository staff actions (login required)

View Item View Item

Downloads

Downloads per month over past year

View more statistics

twitter

Email us: wrap@warwick.ac.uk
Contact Details
About Us