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Related papers: Spectropolarimetric NLTE inversion code SNAPI

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Stokes inversion techniques are very powerful methods for obtaining information on the thermodynamic and magnetic properties of solar and stellar atmospheres. In recent years, very sophisticated inversion codes have been developed that are…

Solar and Stellar Astrophysics · Physics 2022-03-23 C. J. Díaz Baso , A. Asensio Ramos , J. de la Cruz Rodríguez

In this paper we propose an inversion strategy for the analysis of spectropolarimetric measurements taken by {\em Hinode} in the quiet Sun. The spectropolarimeter of the Solar Optical Telescope aboard {\em Hinode} records the Stokes spectra…

Spherical Harmonic Transforms (SHT) are at the heart of many scientific and practical applications ranging from climate modelling to cosmological observations. In many of these areas new, cutting-edge science goals have been recently…

Distributed, Parallel, and Cluster Computing · Computer Science 2013-04-03 Mikolaj Szydlarski , Pierre Esterie , Joel Falcou , Laura Grigori , R. Stompor

We present a new method of Stokes inversion of spectropolarimetric data and evaluate it by taking the example of a SUNRISE/IMaX observation. An archive of synthetic Stokes profiles is obtained by the spectral synthesis of state-of-the-art…

We test our knowledge of the atomic opacity in the solar UV spectrum. Using the atomic data compiled in Paper I from modern, publicly available, databases, we perform calculations that are confronted with space-based observations of the…

Astrophysics · Physics 2009-11-07 C. Allende Prieto , I. Hubeny , D. L. Lambert

In this work, we study the accuracy that can be achieved when inferring the atmospheric information from realistic numerical magneto-hydrodynamic simulations that reproduce the spatial resolution we will obtain with future observations made…

When interpreting spectropolarimetric observations of the solar atmosphere, wavelength variations of the emergent intensity and polarization translate into information on the depth stratification of physical parameters. We aim to quantify…

Solar and Stellar Astrophysics · Physics 2025-01-29 C. J. Díaz Baso , I. Milić , L. Rouppe van der Voort , R. Schlichenmaier

We apply the Tenerife Inversion Code (TIC) to the plage spectropolarimetric observations obtained by the Chromospheric LAyer SpectroPolarimeter (CLASP2). These unprecedented data consist of full Stokes profiles in the spectral region around…

Context - Exoplanetary upper atmospheres are low density environments where radiative processes can compete with collisional ones and introduce non-local thermodynamic equilibrium (NLTE) effects into transmission spectra. Aims - We develop…

Earth and Planetary Astrophysics · Physics 2020-09-09 Mitchell E. Young , Luca Fossati , Tommi T. Koskinen , Michael Salz , Patricio E. Cubillos , Kevin France

We present an automated procedure that derives simultaneously the effective temperature $T_{eff}$, the surface gravity logg, the metallicity [Fe/H], and the equatorial projected rotational velocity vsini for "normal" A and Am stars. The…

Instrumentation and Methods for Astrophysics · Physics 2016-04-20 M. Gebran , W. Farah , F. Paletou , R. Monier , V. Watson

We perform NLTE inversions in a large set of umbral flashes, including the dark fibrils visible within them, and in the quiescent umbra by using the inversion code NICOLE on a set of full Stokes high-resolution Ca II 8542 A observations of…

Solar and Stellar Astrophysics · Physics 2017-08-30 Vasco M. J. Henriques , Michail Mathioudakis , Hector Socas-Navarro , Jaime de la Cruz Rodriguez

This paper forms the second part of our study on how the neglect of NLTE conditions in the formation of Fe I 6301.5 A and the 6302.5 A lines influences the atmosphere obtained by inverting their profiles in LTE. The main cause of NLTE…

Solar and Stellar Astrophysics · Physics 2021-03-15 H. N. Smitha , R. Holzreuter , M. van Noort , S. K. Solanki

The aim of this paper is to analyse the validity of the Dopplergram and lambda-meter techniques for the Doppler diagnostics of solar photospheric velocities using the BaII 4554 A line. Both techniques are evaluated by means of NLTE…

Solar and Stellar Astrophysics · Physics 2015-05-13 N. G. Shchukina , V. L. Olshevsky , E. Khomenko

An inversion technique has been developed to recover LTE one-dimensional model photospheres for late-type stars from very high-resolution high signal-to-noise stellar line profiles. It is successfully applied to the Sun using a set of…

Astrophysics · Physics 2007-05-23 C. Allende Prieto , B. Ruiz Cobo , R. J. Garcia Lopez

Physically realistic models of stellar spectra are needed in a variety of astronomical studies, from the analysis of fundamental stellar parameters, to studies of exoplanets and stellar populations in galaxies. Here we present a new version…

Solar and Stellar Astrophysics · Physics 2023-01-11 Jeffrey M. Gerber , Ekaterina Magg , Bertrand Plez , Maria Bergemann , Ulrike Heiter , Terese Olander , Richard Hoppe

Multi-level non-local thermodynamic equilibrium (NLTE) radiation transfer calculations have become standard throughout the stellar atmospheres community and are applied to all types of stars as well as dynamical systems such as novae and…

Solar and Stellar Astrophysics · Physics 2014-07-02 Peter H. Hauschildt , E. Baron

The program package SME (Spectroscopy Made Easy), designed to perform an analysis of stellar spectra using spectral fitting techniques, was updated due to adding new functions (isotopic and hyperfine splittins) in VALD and including grids…

Instrumentation and Methods for Astrophysics · Physics 2017-10-31 N. Piskunov , T. Ryabchikova , Yu. Pakhomov , T. Sitnova , S. Alexeeva , L. Mashonkina , T. Nordlander

High-resolution observations of the solar chromosphere at millimeter wavelengths are now possible with the Atacama Large Millimeter Array (ALMA), promising to tackle many open problems in solar physics. Observations from other ground and…

Solar and Stellar Astrophysics · Physics 2018-12-12 João M. da Silva Santos , Jaime de la Cruz Rodríguez , Jorrit Leenaarts

The Very Fast Inversion of the Stokes Vector (VFISV) is a Milne-Eddington spectral line inversion code used to determine the magnetic and thermodynamic parameters of the solar photosphere from observations of the Stokes vector in the 6173 A…

Solar and Stellar Astrophysics · Physics 2014-03-17 R. Centeno , J. Schou , K. Hayashi , A. Norton , J. T. Hoeksema , Y. Liu , K. D. Leka , G. Barnes

We present CLEDB, a "single point inversion" algorithm for inferring magnetic parameters using I,Q,U, and V Stokes parameters of forbidden magnetic dipole lines formed in the solar corona. We select lines of interest and construct databases…

Solar and Stellar Astrophysics · Physics 2022-06-01 Alin Razvan Paraschiv , Philip Gordon Judge