Conveners
Poster Session 3.3
- Stefaan Poedts (KU Leuven)
ALMA provides a new set of eyes to look at the stars including our Sun. In particular, the brightness temperatures provided by ALMA give insights about the thermal structure and activity of stellar atmospheres. The Sun, being the closest star, can be observed well resolved and thus be used as a reference case for solar-like stars. The overall aim of the presented study is to construct more...
In this paper, the phenomenon of vortex shedding around a circular cylindrical obstacle is studied numerically in magnetohydrodynamic (MHD) conditions in three spatial dimensions using the numerical code Lare3d. A parametric study was performed for different values of magnetic field perpendicular to the plasma flow plane. This model mimics coronal mass ejection flowing around a coronal loop,...
Based on simultaneous spectroscopic measurements in the H$\alpha$ line and the Mg II k & h lines, Guiping et al. (2019) arrived at two solutions by comparing the observed and synthetic parameters of the H$\alpha$ line with 1D non-LTE modeling. They obtained relatively high temperatures at a microturbulent velocity of 8 km/s, while the temperatures at 16 km/s were standard values. Here we want...
Spectroscopic observations of the emission lines formed in the transition region (TR) commonly show persistent downflows of the order of 10--15 kms$^{-1}$. Their cause, however, is still not fully clear and has remained a matter of debate.
Using two sets of coordinated data from SST, IRIS, and SDO, we aim to understand the cause of such downflows by studying the coronal and TR responses to...
The emission in the near ultraviolet Ca II H & K lines, often quantified via the S-index, has been serving as a prime proxy of solar and stellar magnetic activity. Despite the broad usage of the S-index, the link between coverage of a stellar disk by magnetic features and Ca II H & K emission is not fully understood. In order to fill this gap we developed a physics-based model to calculate the...
The Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO) is one of the most-used data sources in solar physics. Its point spread functions (PSF) were well calibrated by the instrument team, and allows high-quality observations of the solar corona at a resolution of ~1.5 arcsec for quiet Sun and active regions. However, it is suspected that low-emission features such as...
We study the energy distributions of nanoflares in quiet Sun regions, using Differential Emission Measure (DEM) analysis of observations from the 6 EUV filters of the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO). In total, we analyzed 30 sets of AIA/SDO image series distributed evenly between the years 2011 and 2018 to characterize the nanoflare frequency...
