Non-local thermal transport impact on compressive waves in two-temperature coronal loops

TL;DR

This study investigates how non-local thermal transport and electron-ion temperature differences affect the damping and behavior of slow magnetoacoustic waves in solar coronal loops, revealing significant impacts on wave dynamics.

Contribution

It introduces a numerical comparison of local versus non-local thermal transport models and considers two-temperature effects, highlighting their influence on wave damping times.

Findings

Non-local thermal transport can alter damping times by up to 80%.

Finite electron-ion temperature differences can extend damping times by up to 50%.

Non-local effects are significant for plasma with Knudsen numbers greater than 1.

Abstract

Context. Observations of slow magnetoacoustic waves in solar coronal loops suggest that, in hot coronal plasma, heat conduction may be suppressed in comparison with the classical thermal transport model. Aims. We link this suppression with the effect of the non-local thermal transport that appears when the plasma temperature perturbation gradient becomes comparable to the electron mean free path. Moreover, we consider a finite time of thermalisation between electrons and ions, so that separate electron and ion temperatures can occur in the loop. Methods. We numerically compare the influence of the local and non-local thermal transport models on standing slow waves in one- and two-temperature coronal loops. To quantify our comparison, we use the period and damping time of the waves as commonly observed parameters. Results. Our study reveals that non-local thermal transport can result in either shorter or longer slow-wave damping times in comparison with the local conduction model due to the suppression of the isothermal regime. The difference in damping times can reach 80%. For hot coronal loops, we found that the finite equilibration between electron and ion temperatures results in up to 50% longer damping time compared to the one-temperature case. These results indicate that non-local transport will influence the dynamics of compressive waves across a broad range of coronal plasma parameters with Knudsen numbers (the ratio of mean-free-path to temperature scale length) larger than 1%. Conclusions. In the solar corona, the non-local thermal transport shows a significant influence on the dynamics of standing slow waves in a broad range of plasma parameters, while two-temperature effects come into play for hot and less dense loops.