skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: TRANSVERSE OSCILLATIONS OF A LONGITUDINALLY STRATIFIED CORONAL LOOP SYSTEM

Abstract

Collective transverse coronal loop oscillations seem to be detected in observational studies. In this regard, Luna et al. modeled the collective kink-like normal modes of several cylindrical loop systems using the T-matrix theory. This paper investigates the effects of longitudinal density stratification along the loop axis on the collective kink-like modes of the system of coronal loops. The coronal loop system is modeled as cylinders of parallel flux tubes, with two ends of each loop at the dense photosphere. The flux tubes are considered as uniform magnetic fields, with stratified density along the loop axis which changes discontinuously at the lateral surface of each cylinder. The MHD equations are reduced to solve a set of two coupled dispersion relations for frequencies and wavenumbers, in the presence of a stratification parameter. The fundamental and first overtone frequencies and longitudinal wavenumbers are computed. The previous results are verified for an unstratified coronal loop system. Finally, we conclude that an increased longitudinal density stratification parameter will result in an increase of the frequencies. The frequency ratios, first overtones to fundamentals, are very sensitive functions of the density scale height parameter. Therefore, stratification should be included in dynamics of coronal loop systems. For unstratifiedmore » coronal loop systems, these ratios are the same as monoloop ones.« less

Authors:
 [1];  [2]
  1. Institute for Advanced Studies in Basic Sciences, P.O. Box 45195-1159, Zanjan (Iran, Islamic Republic of)
  2. Department of Physics, Zanjan University, P.O. Box 45195-313, Zanjan (Iran, Islamic Republic of)
Publication Date:
OSTI Identifier:
21471190
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 724; Journal Issue: 1; Other Information: DOI: 10.1088/0004-637X/724/1/411; Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; DISPERSION RELATIONS; MAGNETIC FIELDS; MAGNETOHYDRODYNAMICS; OSCILLATIONS; PHOTOSPHERE; S MATRIX; SCALE HEIGHT; SOLAR CORONA; STRATIFICATION; SUN; ATMOSPHERES; DIMENSIONS; FLUID MECHANICS; HEIGHT; HYDRODYNAMICS; MAIN SEQUENCE STARS; MATRICES; MECHANICS; SOLAR ATMOSPHERE; STARS; STELLAR ATMOSPHERES; STELLAR CORONAE

Citation Formats

Fathalian, N, and Safari, H. TRANSVERSE OSCILLATIONS OF A LONGITUDINALLY STRATIFIED CORONAL LOOP SYSTEM. United States: N. p., 2010. Web. doi:10.1088/0004-637X/724/1/411.
Fathalian, N, & Safari, H. TRANSVERSE OSCILLATIONS OF A LONGITUDINALLY STRATIFIED CORONAL LOOP SYSTEM. United States. doi:10.1088/0004-637X/724/1/411.
Fathalian, N, and Safari, H. Sat . "TRANSVERSE OSCILLATIONS OF A LONGITUDINALLY STRATIFIED CORONAL LOOP SYSTEM". United States. doi:10.1088/0004-637X/724/1/411.
@article{osti_21471190,
title = {TRANSVERSE OSCILLATIONS OF A LONGITUDINALLY STRATIFIED CORONAL LOOP SYSTEM},
author = {Fathalian, N and Safari, H},
abstractNote = {Collective transverse coronal loop oscillations seem to be detected in observational studies. In this regard, Luna et al. modeled the collective kink-like normal modes of several cylindrical loop systems using the T-matrix theory. This paper investigates the effects of longitudinal density stratification along the loop axis on the collective kink-like modes of the system of coronal loops. The coronal loop system is modeled as cylinders of parallel flux tubes, with two ends of each loop at the dense photosphere. The flux tubes are considered as uniform magnetic fields, with stratified density along the loop axis which changes discontinuously at the lateral surface of each cylinder. The MHD equations are reduced to solve a set of two coupled dispersion relations for frequencies and wavenumbers, in the presence of a stratification parameter. The fundamental and first overtone frequencies and longitudinal wavenumbers are computed. The previous results are verified for an unstratified coronal loop system. Finally, we conclude that an increased longitudinal density stratification parameter will result in an increase of the frequencies. The frequency ratios, first overtones to fundamentals, are very sensitive functions of the density scale height parameter. Therefore, stratification should be included in dynamics of coronal loop systems. For unstratified coronal loop systems, these ratios are the same as monoloop ones.},
doi = {10.1088/0004-637X/724/1/411},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 724,
place = {United States},
year = {2010},
month = {11}
}