Coronal seismology by slow waves in non-adiabatic conditions

Abstract

Slow magnetoacoustic waves represent an important tool for probing the solar coronal plasma. We quantitatively assess the applicability of the weak thermal conduction theory to coronal seismology by slow waves. We numerically model the linear standing slow wave in a 1D coronal loop, with field-aligned thermal conduction ${\kappa }_{\parallel }$ as a free parameter and no restrictions on its efficiency. The time variations of the perturbed plasma parameters, obtained numerically with full conductivity, are treated as potential observables and analysed with the standard data processing techniques. The slow wave oscillation period is found to increase with ${\kappa }_{\parallel }$ by about 30%, indicating the corresponding modification in the effective wave speed, which is missing from the weak conduction theory. Phase shifts between plasma temperature and density perturbations are found to be well consistent with the approximate weakly conductive solution for all considered values of ${\kappa }_{\parallel }$. In contrast, the comparison of the numerically obtained ratio of temperature and density perturbation amplitudes with the weak theory revealed relative errors up to 30-40%. We use these parameters to measure the effective adiabatic index of the coronal plasma directly as the ratio of the effective slow wave speed to the standard sound speed and in the polytropic assumption, which is found to be justified in a weakly conductive regime only, with relative errors up to 14% otherwise. The damping of the initial perturbation is found to be of a non-exponential form during the first cycle of oscillation, which could be considered as an indirect signature of entropy waves in the corona, also not described by weak conduction theory. The performed analysis and obtained results offer a more robust scheme of coronal seismology by slow waves, with reasonable simplifications and without the loss of accuracy.

arXiv commentAccepted for publication in Front. Astron. Space Sci

References in corpus (31)

• Coronal heating by MHD waves
• Kink oscillations of coronal loops
• Acoustic Oscillations in Solar and Stellar Flaring Loops
• Slow-Mode Magnetoacoustic Waves in Coronal Loops
• Solar coronal magnetic fields derived using seismology techniques applied to omnipresent sunspot waves
• Determination of the Coronal Magnetic Field by Hot Loop Oscillations
• MHD Waves in open coronal structures
• Evidence of thermal conduction suppression in a solar flaring loop by coronal seismology of slow-mode waves
• 3D Coronal Slow Modes: Towards 3D Seismology
• Formation of quasi-periodic slow magnetoacoustic wave trains by the heating/cooling misbalance
• Frequency-dependent damping in propagating slow magneto-acoustic waves
• Magnetohydrodynamic Fast Sausage Waves in the Solar Corona
• Damping of slow magnetoacoustic oscillations by the misbalance between heating and cooling processes in the solar corona
• Seismological constraints on the solar coronal heating function
• The polytropic index of solar coronal plasma in sunspot fan loops and its temperature dependence
• Coronal Quasi-periodic Fast-mode Propagating Wave Trains
• Plasma sloshing in pulse-heated solar and stellar coronal loops
• The effect of magnetic field on the damping of slow waves in the solar corona
• Effect of transport coefficients on excitation of flare-induced standing slow-mode waves in coronal loops
• Mixed properties of slow magnetoacoustic and entropy waves in a plasma with heating/cooling misbalance
• Forward Modelling of Propagating Slow Waves in Coronal Loops and Their Frequency-Dependent Damping
• Large-amplitude quasi-periodic pulsations as evidence of impulsive heating in hot transient loop systems detected in the EUV with SDO/AIA
• X-ray flare oscillations track plasma sloshing along star-disk magnetic tubes in Orion star-forming region
• Determination of transport coefficients by coronal seismology of flare-induced slow-mode waves: Numerical parametric study of 1D loop model
• Legolas: a modern tool for magnetohydrodynamic spectroscopy
• Quasi-periodic pulsations in a solar flare with an unusual phase shift
• Excitation and Damping of Slow Magnetosonic Waves in Flaring Hot Coronal Loops: Effects of Compressive Viscosity
• Role of Non-Ideal Dissipation with Heating-Cooling Misbalance on the Phase Shifts of Standing Slow Magnetohydrodynamic Waves
• Unravelling the components of a multi-thermal coronal loop using magnetohydrodynamic seismology
• Turbulent transport in 2D collisionless guide field reconnection
• Slow Magnetoacoustic Oscillations in Stellar Coronal Loops

Cited by in corpus (5)

• Exploring the origin of multi-periodic pulsations during a white-light flare
• Exact solution to the problem of slow oscillations in coronal loops and its diagnostic applications
• Non-local thermal transport impact on compressive waves in two-temperature coronal loops
• Exploring Standing and Reflected Slow-mode Waves in Flaring Coronal Loops: A Parametric Study Using 2.5D MHD Modeling
• The effect of thermal misbalance on magnetohydrodynamic modes in coronal magnetic cylinders