A5080621441- Solar and Space Plasma Dynamics
- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Solar Radiation and Photovoltaics
- Astronomical Observations and Instrumentation
- Ionosphere and magnetosphere dynamics
- Geotechnical and Geomechanical Engineering
- Seismic Waves and Analysis
- Geomagnetism and Paleomagnetism Studies
- Geophysics and Sensor Technology
- Geophysics and Gravity Measurements
- Cardiovascular Health and Disease Prevention
- Planetary Science and Exploration
- Astrophysics and Star Formation Studies
- Calibration and Measurement Techniques
- Granular flow and fluidized beds
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Advanced Measurement and Detection Methods
- Infrared Target Detection Methodologies
- Particle accelerators and beam dynamics
- Elasticity and Material Modeling
- Glaucoma and retinal disorders
- Historical Geography and Cartography
- Tropical and Extratropical Cyclones Research
Slovak Academy of Sciences
2010-2024
Astronomical Institute of the Slovak Academy of Sciences
2011-2024
Utrecht University
2007
Here we report on the unique observation of flaring coronal loops at solar limb using high resolution imaging spectropolarimetry from Swedish 1-meter Solar Telescope. The vantage position, orientation and nature chromospheric material that filled flare allowed us to determine their magnetic field with unprecedented accuracy weak-field approximation method. Our analysis reveals strengths as 350 Gauss heights up 25 Mm above limb. These measurements are substantially higher than a number...
We investigate the temporal evolution of magnetic flux emerging within a granule in quiet-Sun internetwork at disk center. combined IR spectropolarimetry performed two Fe I lines 1565 nm with speckle-reconstructed G-band imaging. determined field parameters by LTE inversion full Stokes vector using SIR code, and followed their time. To interpret observations, we created geometrical model rising loop 3D. The relevant were matched to observations where possible. then synthesized spectra from...
Aims. To investigate the role of acoustic and magneto-acoustic waves in heating solar chromosphere, observations strong chromospheric lines are analyzed by comparing deposited acoustic-energy flux with total integrated radiative losses. Methods. Quiet-Sun weak-plage regions were observed Ca II 854.2 nm H-alpha Fast Imaging Solar Spectrograph (FISS) at 1.6-m Goode Telescope (GST) on 2019 October 3 H-beta echelle spectrograph attached to Vacuum Tower (VTT) 2018 December 11 June 6. The energy...
On February 12, 2021 two subsequent eruptions occurred above the West limb, as seen along Sun-Earth line. The first event was a typical slow Coronal Mass Ejection (CME), followed $\sim 7$ hours later by smaller and collimated prominence eruption, originating Southward with respect to CME, plasma blob. These events were observed not only SOHO STEREO-A missions, but also suite of remote sensing instruments on-board Solar Orbiter (SolO). This work shows how data acquired Full Sun Imager (FSI),...
Abstract We provide the circumstances and details of fireball observation, search expeditions, recovery, strewn field, physical characteristics Košice meteorite that fell in Slovakia on February 28, 2010. The was only 15th case an observed bolide with a recovered mass subsequent orbit determination. Despite multiple eyewitness reports bolide, three videos from security cameras Hungary were used for field determination computation. Multiple expeditions professionals individual searchers found...
We study the C8.4 class solar flare SOL2016-05-14T11:34 UT using high-resolution spectral imaging in Ca ii 8542 {\AA} line obtained with CRISP spectropolarimeter on Swedish 1-m Solar Telescope. Spectroscopic inversions of non-LTE code NICOLE are used to investigate evolution temperature and velocity structure chromosphere. A comparison stratification flaring non-flaring areas reveals strong footpoint heating during peak lower atmosphere. The footpoints between continuum optical depth at...
Flare loops form an integral part of eruptive events, being detected in the range temperatures from X-rays down to cool chromospheric-like plasmas. While hot are routinely observed by Solar Dynamics Observatory's Atmospheric Imaging Assembly (SDO/AIA), seen off-limb rare. In this paper we employ unique observations SOL2017-09-10T16:06 X8.2-class flare which produced extended arcade loops. The Swedish 1-m Telescope (SST) made a series spectral images Ca II 8542 \r{A} and hydrogen H$\beta$...
Context. The solar radiation in the Lyman- α spectral line of hydrogen plays a significant role illumination chromospheric and coronal structures, such as prominences, spicules, fibrils, cores mass ejections, wind. Moreover, it is important for investigation heliosphere, Earth’s ionosphere, atmospheres planets, moons, comets. Aims. We derive reference quiet-Sun profile that representative from disk during minimum activity. This can serve an incident boundary condition radiative transfer...
Abstract We derived high-precision reference profiles of the Mg ii h and k lines that represent quiet Sun during a minimum solar activity. To do so, we used broad catalog full-Sun mosaics obtained by Interface Region Imaging Spectrograph (IRIS). minimize influence local variations due to on-disk features achieve low levels uncertainties, 12 IRIS without sunspots or other significant signs These were between 2019 April 2020 September in near-ultraviolet spectral range. In this paper, present...
Abstract We demonstrate that changes in the incident radiation Mg ii h and k lines have a significant impact on results of radiative transfer modeling prominence-like plasmas. To uncover extent this allow easy comparison, here we study two cases, one representing minimum solar activity other corresponding to typical conditions during maxima. represent well properties prominence plasma, use 2D non-LTE (i.e., departures from local thermodynamic equilibrium) model fine structures both...
We study a solar spicule observed off-limb using high-resolution imaging spectroscopy in the Ca II 8542 \AA\ line obtained with CRisp Imaging SpectroPolarimeter (CRISP) on Swedish 1-m Solar Telescope. Using new version of non-LTE code NICOLE specifically developed for this problem we invert single- and double-peak profiles. This considers geometry computes atomic populations by solving 1D radiative transfer assuming vertical stratification. The inversion proceeds fitting spectral profiles at...
The solar chromosphere and transition region are highly structured complex regimes. A recent breakthrough has been the identification of dynamic fibrils observed in H alpha as caused by field-aligned magnetoacoustic shocks. We seek to find whether such also Ly alpha. used a brief sequence four high-resolution images limb taken Very high Angular resolution ULtraviolet Telescope (VAULT), which displays many extending retracting jets. measured their top trajectories fitted parabolas 30...
Aims: Changes of the magnetic field and line-of-sight velocities in photosphere are being reported for an M-class flare that originated at a $δ$-spot belonging to active region NOAA 11865. Methods: High-resolution ground-based near-infrared spectropolarimetric observations were acquired simultaneously two photospheric spectral lines, Fe I 10783 Å Si 10786 Å, with Tenerife Infrared Polarimeter Vacuum Tower Telescope (VTT) on 2013 October 15. The covered several stages flare. Inversions...
Abstract An active region mini‐filament was observed with the Vacuum Tower Telescope (VTT) in Tenerife simultaneously Hei infrared triplet using Infrared Polarimeter 1 (TIP 1), H α TESOS Fabry‐Pérot interferometer, and Caii 8542 Å VTT spectrograph. The spectropolarimetric data were inverted HAZEL code profiles modelled by solving a NLTE radiative transfer simple isobaric isothermal 2D slab irradiated both from its bottom sides solar surface. It found that is composed of horizontal fluxtubes,...
Abstract Flare ribbons are bright manifestations of flare energy dissipation in the lower solar atmosphere. For first time, we report on high-resolution imaging spectroscopy observations situated off limb H β and Ca ii 8542 Å lines make a detailed comparison with radiative hydrodynamic simulations. Observations X8.2 class SOL 2017-09-10T16:06 UT obtained Swedish Solar Telescope reveal horizontal emission layers line-wing images located near footpoints loops. The apparent separation between...
Abstract The solar radiation in the cores of Mg ii h and k spectral lines plays a significant role illumination prominences, coronal mass ejections (CMEs), spicules, flare loops, surges. Moreover, these strongly correlates with magnetic activity ultraviolet irradiance affecting photochemistry, especially oxygen nitrogen, middle atmosphere Earth. This work provides data-driven model temporal evolution full-disk profiles over cycle. capability to reproduce for an arbitrary date is...
We present an analysis of off-limb cool flare loops observed by SDO/AIA during the gradual phase SOL2017-09-10T16:06 X8.2-class flare. In EUV channels starting from 335 {\AA} one, appear as dark structures against bright loop arcade. These were precisely coaligned (spatially and temporally) with SST in emission lines hydrogen ionized calcium. Recently published semi-empirical model based on observations serves us to predict level helium recombination continua. The continua synthesized using...
Broad sets of spectroscopic observations comprising multiple lines represent an excellent opportunity for diagnostics the properties prominence plasma and dynamics their fine structures. However, they also bring significant challenges when are compared with synthetic spectra provided by radiative transfer modeling. In this work, we provide a statistical analysis unique dataset coordinated in Lyman (Ly_alpha to Ly_delta) Mg II k h lines. The observed data were obtained Solar Ultraviolet...
Abstract The concepts of radiative and adiabatic equilibria, introduced by Karl Schwarzschild in his seminal paper Ueber das Gleichgewicht der Sonnenatmosphäre published January 1906, are the founding blocks theory transfer, stellar structure, solar physics. Careful reading its later English translation reveals small formal inaccuracies ambiguities but with no consequences whatsoever for final outcomes conclusions. This offers their adjustments respective derivations using contemporary...
Aims.We aim to determine average radial stratifications of various physical parameters throughout the solar photosphere at high angular resolution for non-magnetic and magnetic areas compare these with standard semiempirical 1D modeling 3D hydrodynamics (HD) magnetohydrodynamics (MHD) simulations.
We study off-limb emission of the lower solar atmosphere using high-resolution imaging spectroscopy in H$\beta$ and Ca II 8542 \r{A} lines obtained with CHROMospheric Imaging Spectrometer (CHROMIS) CRisp SpectroPolarimeter (CRISP) on Swedish 1-m Solar Telescope. The line wing images show dark intensity gap between photospheric limb chromosphere which is absent images. calculate synthetic spectra emissions RH code one-dimension spherical geometry find good agreement observations. analysis...