General
The general aim of this project is the investigation of astrophysical processes through the use of stateoftheart numerical codes on massively parallel computers. More specifically, the research in many astrophysical fields requires an understanding of gas dynamical, magnetic, radiative transfer and gravitational phenomena not accessible to purely theoretical analysis. In the framework of this project calculation aimed at understanding the multidimensional structure and evolution of magnetic fields in stellar atmospheres and interiors are carried out, including magnetohydrodynamical aspects, radiative transfer and spectral line polarization. Special emphasis is placed on the comparison of the theoretical/numerical results with observational data.
Members
Results
- Small magnetic loops are observed to appear in the interior of individual granules in the quiet Sun. Using 3D numerical the mechanisms that produce this emergence is discovered. The results have been published in ApJ Letter 859, id. L26 and led by Prof Fernando Moreno-Insertis.
- In an international collaboration, almost 200 solar prominence oscillations events have been catalogued. This is the first statistically significant study of these phenomena done that also includes large-amplitude oscillations. This work has been led by Dr Manuel Luna and published in ApJ Supplement Series, 236, id. 35.
Scientific activity
Related publications
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Large Ion-neutral Drift Velocities and Plasma Heating in Partially Ionized Coronal Rain Blobs
In this paper we present a numerical study of the dynamics of partially ionized coronal rain blobs. We use a two-fluid model to perform a high-resolution 2D simulation that takes into account the collisional interaction between the charged and neutral particles contained in the plasma. We follow the evolution of a cold plasma condensation as it
Martínez-Gómez, David et al.Advertised on:
122022Bibcode -
Observational and numerical characterization of a recurrent arc-shaped front propagating along a coronal fan
Context. Recurrent, arc-shaped intensity disturbances were detected by extreme-ultraviolet channels in an active region. The fronts were observed to propagate along a coronal loop bundle rooted in a small area within a sunspot umbra. Previous works have linked these intensity disturbances to slow magnetoacoustic waves that propagate from the lower
Sieyra, M. V. et al.Advertised on:
112022Bibcode -
Ambipolar Diffusion in the Lower Solar Atmosphere: Magnetohydrodynamic Simulations of a Sunspot
Magnetohydrodynamic (MHD) simulations of the solar atmosphere are often performed under the assumption that the plasma is fully ionized. However, in the lower solar atmosphere a reduced temperature often results in only the partial ionization of the plasma. The interaction between the decoupled neutral and ionized components of such a partially
MacBride, Conor D. et al.Advertised on:
102022Bibcode -
The European Solar Telescope
The European Solar Telescope (EST) is a project aimed at studying the magnetic connectivity of the solar atmosphere, from the deep photosphere to the upper chromosphere. Its design combines the knowledge and expertise gathered by the European solar physics community during the construction and operation of state-of-the-art solar telescopes
Quintero Noda, C. et al.Advertised on:
102022Bibcode -
A 2D Model for Coronal Bright Points: Association with Spicules, UV Bursts, Surges, and EUV Coronal Jets
Coronal bright points (CBPs) are ubiquitous structures in the solar atmosphere composed of hot small-scale loops observed in extreme-ultraviolet (EUV) or X-rays in the quiet Sun and coronal holes. They are key elements to understanding the heating of the corona; nonetheless, basic questions regarding their heating mechanisms, the chromosphere
Nóbrega-Siverio, D. et al.Advertised on:
82022Bibcode -
Doppler-velocity Drifts Detected in a Solar Prominence
We analyzed multiline observations of a quiescent prominence from the slit spectrograph located at the Ondřejov Observatory. Dopplergrams and integrated intensity maps of the whole prominence were obtained from observations in six spectral lines: Ca II H, Hϵ, Hβ, He I D3, Hα, and Ca II IR. By combining integrated intensity maps with non-LTE
Zapiór, Maciej et al.Advertised on:
72022Bibcode -
Modeling the thermal conduction in the solar atmosphere with the code MANCHA3D
Context. Thermal conductivity is one of the important mechanisms of heat transfer in the solar corona. In the limit of strongly magnetized plasma, it is typically modeled by Spitzer's expression where the heat flux is aligned with the magnetic field. Aims: This paper describes the implementation of the heat conduction into the code MANCHA3D with an
Navarro, A. et al.Advertised on:
72022Bibcode -
Generalized Fluid Models of the Braginskii Type
Several generalizations of the well-known fluid model of Braginskii (1965) are considered. We use the Landau collisional operator and the moment method of Grad. We focus on the 21-moment model that is analogous to the Braginskii model, and we also consider a 22-moment model. Both models are formulated for general multispecies plasmas with arbitrary
Hunana, P. et al.Advertised on:
62022Bibcode -
Ambipolar diffusion: Self-similar solutions and MHD code testing. Cylindrical symmetry
Context. Ambipolar diffusion is a process occurring in partially ionised astrophysical systems that imparts a complicated mathematical and physical nature to Ohm's law. The numerical codes that solve the magnetohydrodynamic (MHD) equations have to be able to deal with the singularities that are naturally created in the system by the ambipolar
Moreno-Insertis, F. et al.Advertised on:
62022Bibcode -
Construction of coronal hole and active region magnetohydrostatic solutions in two dimensions: Force and energy balance
Coronal holes and active regions are typical magnetic structures found in the solar atmosphere. We propose several magnetohydrostatic equilibrium solutions that are representative of these structures in two dimensions. Our models include the effect of a finite plasma-β and gravity, but the distinctive feature is that we incorporate a thermal
Terradas, J. et al.Advertised on:
42022Bibcode -
Recent Applications of Bayesian Methods to the Solar Corona
Solar coronal seismology is based on the remote diagnostics of physical conditions in the corona of the Sun by comparison between model predictions and observations of magnetohydrodynamic wave activity. Our lack of direct access to the physical systems of interest makes information incomplete and uncertain so our conclusions are at best
Arregui, I.Advertised on:
32022 -
Methodology for Predicting the Probability Distribution of the Amplitude of Solar Cycle 25
A number of precursor-type methods for solar-cycle prediction are based on the use of regression models and confidence-level estimates. A drawback of these methods is that they do not permit one to make probability statements, nor do they offer straightforward ways to propagate the uncertainty from observations to the quantities of interest. We
Arregui, IñigoAdvertised on:
22022Bibcode -
Probing the Physics of the Solar Atmosphere with the Multi-slit Solar Explorer (MUSE). I. Coronal Heating
The Multi-slit Solar Explorer (MUSE) is a proposed mission composed of a multislit extreme ultraviolet (EUV) spectrograph (in three spectral bands around 171 Å, 284 Å, and 108 Å) and an EUV context imager (in two passbands around 195 Å and 304 Å). MUSE will provide unprecedented spectral and imaging diagnostics of the solar corona at high spatial (
De Pontieu, Bart et al.Advertised on:
22022Bibcode -
Probing the Physics of the Solar Atmosphere with the Multi-slit Solar Explorer (MUSE). II. Flares and Eruptions
Current state-of-the-art spectrographs cannot resolve the fundamental spatial (subarcseconds) and temporal (less than a few tens of seconds) scales of the coronal dynamics of solar flares and eruptive phenomena. The highest-resolution coronal data to date are based on imaging, which is blind to many of the processes that drive coronal energetics
Cheung, Mark C. M. et al.Advertised on:
22022Bibcode -
Transverse kink oscillations of inhomogeneous prominence threads: Numerical analysis and Hα forward modelling
Context. Prominence threads are very long and thin flux tubes that are partially filled with cold plasma. Observations have shown that transverse oscillations are frequent in these solar structures. The observations are usually interpreted as the fundamental kink mode, while the detection of the first harmonic remains elusive. Aims: The properties
Martínez-Gómez, David et al.Advertised on:
22022Bibcode -
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Solar surges related to UV bursts. Characterization through k-means, inversions, and density diagnostics
Context. Surges are cool and dense ejections typically observed in chromospheric lines and closely related to other solar phenomena such as UV bursts or coronal jets. Even though surges have been observed for decades now, questions regarding their fundamental physical properties such as temperature and density, as well as their impact on upper
Nóbrega-Siverio, D. et al.Advertised on:
112021Bibcode -
Large-amplitude longitudinal oscillations in solar prominences simulated with different resolutions
Context. Large-amplitude longitudinal oscillations (LALOs) in solar prominences have been widely studied in recent decades. However, their damping and amplification mechanisms are not well understood. Aims: In this study, we investigate the attenuation and amplification of LALOs using high-resolution numerical simulations with progressively
Liakh, V. et al.Advertised on:
102021Bibcode -
Effect of momentum and heat losses on the hydrodynamic instability of a premixed equidiffusive flame in a Hele-Shaw cell
The linear stage of hydrodynamic instability of a laminar premixed flame propagating in a Hele-Shaw cell is investigated. Our theoretical model takes into account momentum and heat losses, temperature-dependent transport coefficients, and the continuous internal structure of the flame front. The dispersion relation is obtained numerically as a
Han, Yifan et al.Advertised on:
102021Bibcode -
Evidence of the multi-thermal nature of spicular downflows. Impact on solar atmospheric heating
Context. Spectroscopic observations of the emission lines formed in the solar transition region commonly show persistent downflows on the order of 10−15 km s−1. The cause of such downflows, however, is still not fully clear and has remained a matter of debate. Aims: We aim to understand the cause of such downflows by studying the coronal and
Bose, Souvik et al.Advertised on:
102021Bibcode