Related papers: Coronal loops above an Active Region - observation…
Aims. The goal is to employ a 3D magnetohydrodynamics (MHD) model including spectral synthesis to model the corona in an observed solar active region. This will allow us to judge the merits of the coronal heating mechanism built into the 3D…
Context. We have conducted a 3D MHD simulation of the solar corona above an active region (AR) in full scale and high resolution, which shows coronal loops, and plasma flows within them, similar to observations. Aims. We want to find the…
The corona of the Sun is dominated by emission from loop-like structures. When observed in X-ray or extreme ultraviolet emission, these million K hot coronal loops show a more or less constant cross section. In this study we show how the…
We aim to reproduce the structure of the corona above a solar active region as seen in the extreme ultraviolet (EUV) using a three-dimensional magnetohydrodynamic (3D MHD) model. The 3D MHD data-driven model solves the induction equation…
We present the first model that couples the formation of the corona of a solar active region to a model of the emergence of a sunspot pair. This allows us to study when, where, and why active region loops form, and how they evolve. We use a…
Context. The structure and heating of coronal loops are investigated since decades. Established scaling laws relate fundamental quantities like the loop apex temperature, pressure, length, and the coronal heating. Aims. We test such scaling…
The evolution of a coronal loop is studied by means of numerical simulations of the fully compressible three-dimensional magnetohydrodynamic equations using the HYPERION code. The footpoints of the loop magnetic field are advected by random…
The solar corona is much hotter than the photosphere and chromosphere, but the physical mechanism responsible for heating the coronal plasma remains unidentified yet. The thermal microwave emission, which is produced in strong magnetic…
We study the magnetic field and current structure associated with a coronal loop. Through this we investigate to what extent the assumptions of a force-free magnetic field break down and where they might be justified. We analyse a 3D MHD…
The outer atmosphere of the Sun is composed of plasma heated to temperatures well in excess of the visible surface. We investigate short cool and warm (<1 MK) loops seen in the core of an active region to address the role of field-line…
It is extremely difficult to simulate the details of coronal heating and also make meaningful predictions of the emitted radiation. Thus, testing realistic models with observations is a major challenge. Observational signatures of coronal…
Coronal loops are the basic building block of the upper solar atmosphere. Comprehending how these are energized, structured, and evolve is key to understanding stellar coronae. Here we investigate how the energy to heat the loop is…
Coronal loops are the basic structures of the solar transition region and corona. The understanding of physical mechanism behind the loop heating, plasma flows, and filling are still considered a major challenge in the solar physics. The…
We perform MHD modeling of a single bright coronal loop to include the interaction with a non-uniform magnetic field. The field is stressed by random footpoint rotation in the central region and its energy is dissipated into heating by…
The solar atmosphere may be heated by Alfven waves that propagate up from the convection zone and dissipate their energy in the chromosphere and corona. To further test this theory, we consider wave heating in an active region observed on…
Coronal loops are fundamental building blocks of the solar active regions and the corona. Therefore, a clear understanding of the physics of coronal loops will help us understand the physics of active region heating in particular and…
The nature and detailed properties of the heating of the million-degree solar corona are important issues that are still largely unresolved. Nanoflare heating might be dominant in active regions and quiet Sun, although direct signatures of…
Solar corona is much hotter than lower layers of the solar atmosphere-photosphere and chromosphere. The coronal temperature is up to 1MK in quiet sun areas, while up to several MK in active regions, which implies a key role of magnetic…
We investigate a possibility of heating of the loops and other closed magnetic structures in active regions of the solar corona by the flow of solar wind (plus other flows that may be present) across the magnetic field lines (that are…
Coronal rain consists of cool and dense plasma condensations formed in coronal loops as a result of thermal instability. Previous numerical simulations of thermal instability and coronal rain formation have relied on artificially adding a…