相关论文: A benchmark study of atomic models for the transit…
To predict line emission in the solar atmosphere requires models which are fundamentally different depending on whether the emission is from the chromosphere or the corona. At some point between the two regions, there must be a change…
The aim of this work is to improve the modelling of ion populations in higher density, lower temperature astrophysical plasmas, of the type commonly found in lower solar and stellar atmospheres. Ion population models for these regions…
Extensions have been made recently to the coronal approximation for the purpose of modelling line emission from carbon and oxygen in the lower solar atmosphere. The same modelling is used here for other elements routinely observed in the…
The solar transition region (TR) is a narrow interface between the chromosphere and corona, where emitted radiation contains critical information pertinent to coronal heating processes. We conducted 2-dimensional radiation…
The reconstruction of the differential emission measure (DEM) from observations of spectral line intensities provides information on the temperature distribution of the emission measure in the region observed. The inversion process is known…
Prompted by high resolution observations, I propose an explanation for the 40+ year old problem of structure and energy balance in the solar transition region. The ingredients are simply cross-field diffusion of neutral atoms from cool…
We investigate the relative contributions from the transition region and corona of coronal loops observed by the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO). Using EBTEL (Enthalpy-Based Thermal Evolution of…
Dating back to the first observations of the on-disk corona, there has been a qualitative link between the photosphere's magnetic network and enhanced transition-temperature plasma emission. These observations led to the development of a…
We review the coronal visible and infrared lines, collecting previous observations, and comparing, whenever available, observed radiances with those predicted by various models: the quiet Sun, a moderately active Sun, and an active region…
The physical processes in the solar corona that shape the solar wind remain an active research topic. Modeling efforts have shown that energy and plasma exchanges near the transition region plays a crucial role in modulating solar wind…
The ion populations most frequently adopted for diagnostics in collisional plasmas are derived from the density independent, coronal approximation. In higher density, lower temperature conditions, ionisation rates are enhanced once…
We present a study of the differential emission measure (DEM) of a `quiet Sun' area observed in the extreme ultraviolet at normal incidence by the Coronal Diagnostic Spectrometer (CDS) on the SOHO spacecraft. The data used for this work…
The brightness of the emission from coronal loops in the solar atmosphere is strongly dependent on the temperature and density of the confined plasma. After a release of energy, these loops undergo a heating and upflow phase, followed by a…
In the previous works the significance of the symmetric and non-symmetric ion-atom absorption processes in far UV and EUV regions within a model of the quiet Sun atmosphere, has been studied. The considered processes were the processes of…
Transition region explosive events are characterized by non-Gaussian profiles of the emission lines formed at transition region temperatures, and they are believed to be manifestations of small-scale reconnection events in the transition…
We investigate the morphology and temporal variability of a quiet Sun network region in different solar layers. The emission in several EUV spectral lines through both raster and slot time series, recorded by EIS/Hinode is studied along…
Context: The sharp temperature and density gradients in the coronal transition region are a challenge for models and observations. Aims: We set out to get linearly- and quadratically-weighted average electron densities in the region…
The transition region is a thin layer of the solar atmosphere that controls the energy loss from the solar corona. Large numbers of grid points are required to resolve this thin transition region fully in numerical modeling. In this study,…
It is typically assumed that emission in the passbands of the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO) is dominated by single or several strong lines from ions that under equilibrium conditions are…
The Sun is a standard reference object for Astrophysics and also a fascinating subject of study in its own right. X-ray and extreme ultraviolet movies of the Sun's atmosphere show an extraordinary diversity of plasma phenomena, from barely…