Dynamic formation of multi-threaded prominences in arcade configurations

TL;DR

This study models the formation and dynamics of solar prominences using 2D magnetohydrodynamic simulations with stochastic localized heating, revealing how heating influences prominence structure, stability, and observable properties.

Contribution

It introduces a 2D threaded prominence model with stochastic heating, providing new insights into prominence morphology, stability, and dynamics not captured by previous 1D models.

Findings

Random localized heating affects prominence morphology and mass.

Stronger heating leads to faster condensation and larger prominences.

Condensation rates scale with heating amplitude and match observations.

Abstract

With this study, we aim to understand the nature of prominences, governed by their formation process. We use a state-of-the-art threaded prominence model within a dipped magnetic arcade. The non-ideal magnetohydrodynamic (MHD) equations are solved using the open-source MPI-AMRVAC MHD toolkit. Unlike many previous 1D models, we study the full 2D dynamics in a fixed-shaped arcade. This allows for sideways field deformations and cross-field thermodynamic coupling. To achieve a realistic setup we consider field-aligned thermal conduction, radiative cooling and heating, wherein the latter combines a steady background and a localized stochastic component. The stochastic component simulates energy pulses localized in time and space at the footpoints of the magnetic arcade. We vary the height and amplitude of the localized heating and observe how it influences the prominence, its threads, and its overall dynamics. We show the importance of random localized heating in the evolution of prominences and their threaded structure. Random heating strongly influences the morphology of the prominence threaded structure, the area, the mass the threads reach, their minimum temperature and their average density. More importantly, the strength of the localized heating plays a role in maintaining the balance between condensation and draining, affecting the general prominence stability. Stronger sources form condensations faster and result in larger and more massive prominences. We show how the condensation rates scale with the amplitude of the heating inputs and quantify how these rates match with values from observations. We detail how stochastic sources determine counterstreaming flows and oscillations of prominence threads.