A5073295952- Solar and Space Plasma Dynamics
- Stellar, planetary, and galactic studies
- Geomagnetism and Paleomagnetism Studies
- Astro and Planetary Science
- Ionosphere and magnetosphere dynamics
- Atmospheric Ozone and Climate
- Geophysics and Gravity Measurements
- Radiative Heat Transfer Studies
- Gas Dynamics and Kinetic Theory
- Astrophysics and Star Formation Studies
- Magneto-Optical Properties and Applications
- Numerical methods in inverse problems
- Solar Radiation and Photovoltaics
- Atomic and Subatomic Physics Research
- Calibration and Measurement Techniques
- Quantum optics and atomic interactions
- Electron Spin Resonance Studies
- Adaptive optics and wavefront sensing
- Photosynthetic Processes and Mechanisms
- Matrix Theory and Algorithms
- Wind and Air Flow Studies
- Advanced X-ray Imaging Techniques
- Oceanographic and Atmospheric Processes
- Electromagnetic Scattering and Analysis
- Particle Accelerators and Free-Electron Lasers
Instituto de Astrofísica de Canarias
2016-2024
Universidad de La Laguna
2016-2024
Università della Svizzera italiana
2021-2022
Istituto Ricerche Solari Locarno
2019-2022
The European Solar Telescope (EST) is a project aimed at studying the magnetic connectivity of solar atmosphere, from deep photosphere to upper chromosphere. Its design combines knowledge and expertise gathered by physics community during construction operation state-of-the-art telescopes operating in visible near-infrared wavelengths: Swedish 1m (SST), German Vacuum Tower (VTT) GREGOR, French T\'elescope H\'eliographique pour l'\'Etude du Magn\'etisme et des Instabilit\'es Solaires...
A novel space experiment achieves an unprecedented map of solar magnetic fields from the photosphere to base corona.
ABSTRACT We highlight the main results of a radiative transfer investigation on magnetic sensitivity solar Mg ii k resonance line at 2795.5 Å, accounting for joint action Hanle and Zeeman effects as well partial frequency redistribution phenomena. confirm that center, linear polarization signals produced by scattering processes are measurable, they sensitive, via effect, to fields with strengths between 5 50 G, approximately. also show effect produces conspicuous circular signals, especially...
Abstract The CLASP2 (Chromospheric LAyer Spectro-Polarimeter 2) sounding rocket mission was launched on 2019 April 11. measured the four Stokes parameters of Mg ii h and k spectral region around 2800 Å along a 200″ slit at three locations solar disk, achieving first spatially spectrally resolved observations polarization in this near-ultraviolet region. focus work presented here is center-to-limb variation linear across these resonance lines, which produced by scattering anisotropic...
Abstract We report the first detection of a magnetic discontinuity in upper solar chromosphere associated with coronal loop brightening. Our findings are based on novel observations obtained by Chromospheric LAyer SpectroPolarimeter (CLASP2.1) suborbital space experiment. During its short 6 minute flight, CLASP2.1 successfully spectropolarimetric data across Mg ii h and k lines, which allowed us to map longitudinal field at multiple heights active region. our observation, we found...
The spectral line polarization encodes a wealth of information about the thermal and magnetic properties solar atmosphere. Modeling Stokes profiles strong resonance lines is, however, complex problem both from theoretical computational point view, especially when partial frequency redistribution (PRD) effects need to be taken into account. In this work, we consider two-level atom in presence fields arbitrary intensity (Hanle-Zeeman regime) orientation, deterministic micro-structured. Working...
We apply the Tenerife Inversion Code (TIC) to plage spectropolarimetric observations obtained by Chromospheric LAyer SpectroPolarimeter (CLASP2). These unprecedented data consist of full Stokes profiles in spectral region around Mg II h and k lines for a single slit position, with two thirds 200 arcsec crossing rest an enhanced network. A former analysis these had allowed us infer longitudinal component magnetic field applying weak approximation (WFA) circular polarization profiles, assign...
Context. The correct modeling of the scattering polarization signals observed in several strong resonance lines requires taking partial frequency redistribution (PRD) phenomena into account. Aims. This work aims at assessing impact and range validity angle-averaged AA approximation with respect to general angle-dependent (AD) treatment PRD effects lines, focus on solar Ca i 4227 {\AA} line. Methods. Spectral line is modeled by solving radiative transfer problem for polarized radiation, under...
Twenty-five years ago, enigmatic linear polarization signals were discovered in the core of sodium D1 line. The only explanation that could be found implied solar chromosphere is practically unmagnetized, contradiction with other evidences. This opened a paradox has challenged physicists for many years. Here we present its solution, demonstrating these can properly explained presence magnetic fields gauss range. result opens novel diagnostic window exploring elusive magnetism...
We present the theoretical framework and numerical methods we have implemented to solve problem of generation transfer polarized radiation in spectral lines out local thermodynamical equilibrium, while accounting for scattering polarization, partial frequency redistribution, J-state interference, hyperfine structure. The resulting radiative code allows modeling impact magnetic fields arbitrary strength orientation through Hanle, incomplete Paschen-Back, magneto-optical effects. also evaluate...
The linear polarization pattern produced by scattering processes in the Ca I resonance line at 4227 angstroms is a valuable observable for probing solar atmosphere. Via Hanle effect, very significant Q/I and U/I line-center signals are sensitive to presence of magnetic fields lower chromosphere with strengths between 5 125 G, approximately. On other hand, partial frequency redistribution (PRD) produces sizable wings profile, which have always been thought be insensitive fields....
Abstract The linear polarization produced by scattering processes in the hydrogen Ly α line of solar disk radiation is a key observable for probing chromosphere–corona transition region (TR) and underlying chromospheric plasma. While line-center signal encodes information on magnetic field three-dimensional structure TR, sizable signals that joint action partial frequency redistribution J -state interference produce wings have generally been thought to be sensitive only thermal atmosphere....
Abstract Radiative transfer investigations of the solar Mg ii h and k resonance lines around 280 nm have shown that, while their circular polarization (Stokes V ) signals arise from Zeeman effect, linear profiles Q U are dominated by scattering anisotropic radiation Hanle magneto-optical (MO) effects. Using unprecedented observations Mn i obtained Chromospheric LAyer Spectro-Polarimeter (CLASP2), here we investigate how at different wavelengths (i.e., center, near far wings line) vary with...
Context. Measurable linear scattering polarization signals have been predicted and detected at the solar disk center in cores of chromospheric lines. These forward-scattering signals, which are high interest for magnetic field diagnostics, always modeled either under assumption complete frequency redistribution (CRD), or taking partial (PRD) effects into account angle-averaged (AA) approximation. Aims. The aim this work is to assess suitability CRD PRD–AA approximations modeling produced by...
Abstract We apply the HanleRT Tenerife Inversion Code to spectropolarimetric observations obtained by Chromospheric Layer Spectropolarimeter. This suborbital space experiment measured variation with wavelength of four Stokes parameters in near-ultraviolet spectral region Mg ii h and k lines over a solar disk area containing part an active plage edge sunspot penumbra. infer stratification temperature, electron density, line-of-sight velocity, microturbulent longitudinal component magnetic...
Context . Several numerical problems require the interpolation of discrete data that present at same time (i) complex smooth structures and (ii) various types discontinuities. The radiative transfer in solar stellar atmospheres is a typical example such problem. This calls for high-order well-behaved techniques are able to interpolate both discontinuous data. Aims article expands on different nonlinear capable guaranteeing accuracy handling discontinuities an accurate non-oscillatory...
We study the circular polarization of Mn I resonance lines at 279.56, 279.91, and 280.19 nm (hereafter, UV multiplet) by means radiative transfer modeling. In 2019, CLASP2 mission obtained unprecedented spectropolarimetric data in a region solar ultraviolet including Mg II h k two subordinate triplet, as well lines. The first analysis such data, particular those corresponding to plage region, allowed inference longitudinal magnetic field from photosphere upper chromosphere just below...
Context. Several strong resonance lines, such as H I Ly- α , Mg II k, Ca K, and 4227 Å, are characterized by deep broad absorption profiles in the solar intensity spectrum. These lines show conspicuous linear scattering polarization signals when observed quiet regions close to limb. Such a characteristic triplet-peak structure with sharp peak line core extended wing lobes. The is sensitive presence of magnetic fields through Hanle effect, which however known not operate wings. Recent...
The Sr~{\sc i} 4607~\AA\ spectral line shows one of the strongest scattering polarization signals in visible solar spectrum. amplitude this signal is expected to vary at granular spatial scales, due combined action Hanle effect and local anisotropy radiation field. Observing these variations would be great interest because it provide precious information on small-scale activity photosphere. At present, few detections such have been reported. This difficulty measurements, which require...
Abstract The long-standing paradox of the linear polarization signal Na i D 1 line was recently resolved by accounting for atom’s hyperfine structure and detailed spectral incident radiation field. That modeling relied on simplifying angle-averaged (AA) approximation partial frequency redistribution (PRD) in scattering, which potentially neglects important angle–frequency couplings. This work aims at evaluating suitability a PRD-AA 2 lines through comparisons with general angle-dependent...
Aims. This work aims to identify the relevant physical processes in shaping intensity and polarization patterns of solar K I D lines through spectral syntheses, placing particular emphasis on 2 line. Methods. The theoretical Stokes profiles were obtained by numerically solving radiative transfer problem for polarized radiation considering one-dimensional semi-empirical models atmosphere. calculations account scattering polarization, partial frequency redistribution (PRD) effects, hyperfine...
We investigate the main physical mechanisms that shape intensity and polarization of Ba II D1 line at 4934 angstroms via radiative transfer numerical experiments. focus especially on scattering linear arising from spectral structure anisotropic radiation in wavelength interval spanned by line's hyperfine (HFS) components odd isotopes barium. After verifying presence low-energy metastable levels only impacts amplitude, but not shape, polarization, we relied a two-term atomic model neglects...
Abstract We investigate the main physical mechanisms that shape intensity and polarization of Ba ii D 1 line at 4934 Å via radiative transfer numerical experiments. focus especially on scattering linear arising from spectral structure anisotropic radiation in wavelength interval spanned by line’s hyperfine (HFS) components odd isotopes barium. After verifying presence low-energy metastable levels only impacts amplitude, but not shape, polarization, we relied a two-term atomic model neglects...
Measurable linear scattering polarization signals have been predicted and detected at the solar disk center in core of chromospheric lines. These forward-scattering signals, which are high interest for magnetic field diagnostics, always modeled either under assumption complete frequency redistribution (CRD), or taking partial (PRD) effects into account angle-averaged (AA) approximation. This work aims assessing suitability CRD PRD-AA approximations modeling produced by presence an inclined...