English
Related papers

Related papers: Linear wavelength correlation matrices of photosph…

200 papers

For many years various asymmetrical profiles of different spectral lines emitted from solar flares have been frequently observed. These asymmetries or line shifts are caused predominantly by vertical mass motions in flaring layers and they…

Astrophysics · Physics 2007-05-23 A. Berlicki

We study the propagation of waves from the photosphere to the chromosphere of sunspots. From time series of cospatial Ca II H (including its line blends) intensity spectra and polarimetric spectra of Si I 1082.7 nm and He I 1083.0 nm we…

Solar and Stellar Astrophysics · Physics 2015-05-20 T. Felipe , E. Khomenko , M. Collados , C. Beck

We study theoretically the spatial correlations between the intensities measured at the input and output planes of a disordered scattering medium. We show that at large optical thicknesses, a long-range spatial correlation persists and…

Optics · Physics 2015-09-23 N. Fayard , A. Cazé , R. Pierrat , R. Carminati

In an effort to estimate the largely unknown effects of photospheric temperature fluctuations on spectroscopic abundance determinations, we have studied the problem of LTE line formation in the inhomogeneous solar photosphere based on…

Astrophysics · Physics 2009-11-07 M. Steffen , H. Holweger

Simulations of molecular clouds often begin from highly idealised initial conditions, such as a uniform-density sphere with an artificially imposed turbulent velocity field. While the resulting structures may appear qualitatively similar to…

Astrophysics of Galaxies · Physics 2023-01-25 F. D. Priestley , P. C. Clark , A. P Whitworth

Because of the complex physics that governs the formation of chromospheric lines, interpretation of solar chromospheric observations is difficult. The origin and characteristics of many chromospheric features are, because of this,…

During solar flares, spectral lines formed in the photosphere have been shown to exhibit changes to their profiles despite the challenges of energy transfer to these depths. Recent work has shown that deep-forming spectral lines are subject…

Solar and Stellar Astrophysics · Physics 2024-01-05 Aaron J. Monson , Mihalis Mathioudakis , Adam F. Kowalski

Future solar missions and ground-based telescopes aim to understand the magnetism of the solar chromosphere. We performed a supporting study in Quintero Noda et al. (2016) focused on the infrared Ca II 8542 A line and we concluded that is…

Solar and Stellar Astrophysics · Physics 2016-12-07 C. Quintero Noda , T. Shimizu , Y. Katsukawa , J. de la Cruz Rodriguez , M. Carlsson , T. Anan , T. Oba , K. Ichimoto , Y. Suematsu

Spectral lines allow us to probe the thermodynamics of the solar atmosphere, but the shape of a single spectral line may be similar for different thermodynamic solutions. Multiline analyses are therefore crucial, but computationally…

Solar and Stellar Astrophysics · Physics 2021-05-19 Brandon Panos , Lucia Kleint , Sviatoslav Voloshynovskiy

We analyze the propagation of waves in sunspots from the photosphere to the chromosphere using time series of co-spatial Ca II H intensity spectra (including its line blends) and polarimetric spectra of Si I 10827 and the He I 10830…

Solar and Stellar Astrophysics · Physics 2015-05-19 T. Felipe , E. Khomenko , M. Collados , C. Beck

Chromospheric heating is an important ingredient in the energy budget of the solar atmosphere, which is challenging to quantify from observations. By using 3D radiative magnetohydrodynamic simulations of the solar atmosphere combined with…

Solar and Stellar Astrophysics · Physics 2026-01-06 Elias R. Udnæs , Tiago M. D. Pereira

Sunspots are transient, magnetically intense features that host oscillations linked to magnetohydrodynamic (MHD) waves. These waves may contribute to plasma heating and drive mass flows in the solar wind. Beyond their energetic role, they…

Solar and Stellar Astrophysics · Physics 2026-05-20 Kartika Sangal , A. K. Srivastava , Libo Fu , Ding Yuan , Song Feng , Yuandeng Shen

Chromospheric inferences rely on the interpretation of spectral lines that are formed under Non-Local Thermodynamic Equilibrium (NLTE) conditions. In the presence of oscillations, changes in the opacity impact the response height of the…

Solar and Stellar Astrophysics · Physics 2023-02-22 T. Felipe , H. Socas-Navarro

We study extreme-ultraviolet emission line spectra derived from three-dimensional magnetohydrodynamic models of structures in the corona. In order to investigate the effects of increased magnetic activity at photospheric levels in a…

Solar and Stellar Astrophysics · Physics 2009-04-16 Pia Zacharias , Sven Bingert , Hardi Peter

We analyze a 1-hour time series of Ca II H intensity spectra and polarimetric spectra around 630 nm to derive the signature of the chromospheric heating and to investigate its relation to magnetic fields. We derived several characteristic…

Astrophysics · Physics 2008-02-08 C. Beck , W. Schmidt , R. Rezaei , W. Rammacher

Context. The wings of the Ca II H and K lines provide excellent photospheric temperature diagnostics. At the Swedish 1-meter Solar Telescope the blue wing of Ca II H is scanned with a narrowband interference filter mounted on a rotation…

Solar and Stellar Astrophysics · Physics 2012-12-18 V. M. J. Henriques

We use state-of-the-art radiation-MHD simulations and 3D non-LTE radiative transfer computations to investigate \Halpha\ line formation in the solar chromosphere and apply the results of this investigation to develop the potential of…

Solar and Stellar Astrophysics · Physics 2015-06-04 Jorrit Leenaarts , Mats Carlsson , Luc Rouppe van der Voort

Acoustic waves are one of the primary suspects besides magnetic fields for the chromospheric heating process to temperatures above radiative equilibrium (RE). We derived the mechanical wave energy as seen in line-core velocities to obtain a…

Solar and Stellar Astrophysics · Physics 2015-05-13 C. Beck , E. Khomenko , R. Rezaei , M. Collados

We investigate the diagnostic potential of the spectral lines at 850 nm for understanding the magnetism of the lower atmosphere. For that purpose, we use a newly developed 3D simulation of a chromospheric jet to check the sensitivity of the…

We investigate the effects of coherent isotropic continuum scattering on the formation of spectral lines in local thermodynamic equilibrium (LTE) using 3D hydrodynamical and 1D hydrostatic model atmospheres of red giant stars. Continuum…

Solar and Stellar Astrophysics · Physics 2011-08-18 W. Hayek , M. Asplund , R. Collet , Å. Nordlund
‹ Prev 1 2 3 10 Next ›