Magnetohydrodynamic waves in two-dimensional prominences embedded in coronal arcades

Journal Article · Wed Nov 20 04:00:00 EST 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/778/1/49· OSTI ID:22342013

Terradas, J.; Soler, R.; Díaz, A. J.; Oliver, R.

Solar prominence models used so far in the analysis of MHD waves in two-dimensional structures are quite elementary. In this work, we calculate numerically magnetohydrostatic models in two-dimensional configurations under the presence of gravity. Our interest is in models that connect the magnetic field to the photosphere and include an overlying arcade. The method used here is based on a relaxation process and requires solving the time-dependent nonlinear ideal MHD equations. Once a prominence model is obtained, we investigate the properties of MHD waves superimposed on the structure. We concentrate on motions purely two-dimensional, neglecting propagation in the ignorable direction. We demonstrate how, by using different numerical tools, we can determine the period of oscillation of stable waves. We find that vertical oscillations, linked to fast MHD waves, are always stable and have periods in the 4-10 minute range. Longitudinal oscillations, related to slow magnetoacoustic-gravity waves, have longer periods in the range of 28-40 minutes. These longitudinal oscillations are strongly influenced by the gravity force and become unstable for short magnetic arcades.

• OSTI ID: 22342013
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 778; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
CONFIGURATION
EQUATIONS
GRAVITATION
GRAVITY WAVES
HYDROMAGNETIC WAVES
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
OSCILLATIONS
PHOTOSPHERE
RELAXATION
SOLAR PROMINENCES
SUN
TIME DEPENDENCE
TWO-DIMENSIONAL CALCULATIONS