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Related papers: Penumbral models in the light of Hinode spectropol…

200 papers

We investigate the temporal relation between the Evershed flow, dot-like bright features (penumbral grain), the complex magnetic field structure, and dark lanes (dark core) along bright filaments in a sunspot penumbra. We use a time series…

Solar and Stellar Astrophysics · Physics 2015-05-27 M. Kubo , K. Ichimoto , B. W. Lites , R. A. Shine

Accurate emission line fluxes from planetary nebulae (PNe) provide important constraints on the nature of the final phases of stellar evolution. Large, evolved PNe may trace the latest stages of PN evolution, where material from the AGB…

Astrophysics · Physics 2009-11-11 G. J. Madsen , D. J. Frew , Q. A. Parker , R. J. Reynolds , L. M. Haffner

We examine spectropolarimetric data from the CoMP instrument, acquired during the evolution of the September 10th 2017 X8.2 solar flare on the western solar limb. CoMP captured linearly polarized light from two emission lines of Fe XIII at…

Solar and Stellar Astrophysics · Physics 2019-12-25 Ryan J. French , Philip G. Judge , Sarah A. Matthews , Lidia van Driel-Gesztelyi

Context. Understanding the close relationship between the plasma and the magnetic field is important to describe and explain the observed complex dynamics of solar prominences. Aims. We determine if a close relationship between plasma and…

Solar and Stellar Astrophysics · Physics 2017-11-01 P. J. Levens , N. Labrosse , B. Schmieder , A. López Ariste , L. Fletcher

Relying on the assumption that the interchange convection of magnetic flux tubes is the physical cause for the existence of sunspot penumbrae, we propose a model in which the dynamical evolution of a thin magnetic flux tube reproduces the…

Astrophysics · Physics 2016-08-30 R. Schlichenmaier , K. Jahn , H. U. Schmidt

A phenomenological approach is presented that allows one to model, and thereby interpret, photoemission spectra of strongly correlated electron systems. A simple analytical formula for the self-energy is proposed. This self-energy describes…

Strongly Correlated Electrons · Physics 2009-11-07 Krzysztof Byczuk , Ralf Bulla , Ralph Claessen , Dieter Vollhardt

The advancement of millimeter wave and terahertz technologies have revolutionized high speed wireless networks and precise tracking systems. These technologies offer unique penetration capabilities in specific scenarios, significantly…

Plasma Physics · Physics 2023-11-15 Wenbo Liu , Peian Li , Guohao Liu , Jianjun Ma , Houjun Sun

The vertical stratification of the magnetic field strength in sunspot penumbrae is investigated by means of spectropolarimetric observations at high spatial resolution from the Hinode spacecraft. Assuming that the magnetic field changes…

Astrophysics · Physics 2009-11-13 J. M. Borrero , S. K. Solanki

We review the recent advances in the pulsar high-energy $\gamma$-ray observation and the electrodynamics of the pulsar magnetospheres from the early vacuum model to the recent plasma-filled models by the numerical simulations. The numerical…

High Energy Astrophysical Phenomena · Physics 2024-03-12 Gang Cao , Xiongbang Yang , Li Zhang

Particle-in-Cell (PIC) simulation codes have wide applicability to first-principles modeling of multidimensional nonlinear plasma phenomena, including wake-field accelerators. This review addresses both finite difference and pseudo-spectral…

Plasma Physics · Physics 2014-08-07 Brendan B. Godfrey

Spectral components of continuous squeezed fields are entangled. In this article we review and clarify this phenomenon by analyzing systematically the relations between the correlations of modes filtered from stationary continuous fields…

Quantum Physics · Physics 2015-07-03 Stefano Zippilli , Giovanni Di Giuseppe , David Vitali

Polar faculae are bright features that can be detected in solar limb observations and they are related to magnetic field concentrations. Although there is a large number of works studying them, some questions about their nature as their…

Solar and Stellar Astrophysics · Physics 2016-05-25 C. Quintero Noda , Y. Suematsu , B. Ruiz Cobo , T. Shimizu , A. Asensio Ramos

Context. The Evershed effect, a nearly horizontal outflow of material seen in the penumbrae of sunspots in the photospheric layers, is a common characteristic of well-developed penumbrae, but is still not well understood. Even less is known…

Solar and Stellar Astrophysics · Physics 2017-11-08 A. Siu-Tapia , A. Lagg , S. K. Solanki , M. van Noort , J. Jurčák

We model the deepest observable layers of dark sunspot umbral atmospheres in terms of an empirical model which equally describes observed near infrared continuum intensities and line profiles. We use the umbral continuum intensity at 1.67…

Solar and Stellar Astrophysics · Physics 2012-10-17 Goetz Stellmacher , Eberhard Wiehr

Several important mechanisms that explain the coherent pulsar radio emission rely on streaming (or beam) instabilities of the relativistic pair plasma in a pulsar magnetosphere. However, it is still not clear whether a streaming instability…

High Energy Astrophysical Phenomena · Physics 2021-06-02 Alina C. Manthei , Jan Benáček , Patricio A. Muñoz , Jörg Büchner

We use WMAP5 and other cosmological data to constrain model parameters in quintessence cosmologies, focusing also on their shift when we allow for non-vanishing neutrino masses. The Ratra-Peebles (RP) and SUGRA potentials are used here, as…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-28 G. La Vacca , J. R. Kristiansen

Simulated dark matter haloes are fitted by self-similar, universal density profiles, where the scaled parameters depend only on a scaled (truncation) radius which, in turn, is supposed to be independent on the mass and the formation…

Astrophysics · Physics 2007-05-23 R. Caimmi , C. Marmo

The aim of this work is the determination of the twist, writhe, and self magnetic helicity of penumbral filaments located in an inner Sunspot penumbra. To this extent, we inverted data taken with the spectropolarimeter (SP) aboard Hinode…

Solar and Stellar Astrophysics · Physics 2015-03-19 Basilio Ruiz Cobo , Klaus G. Puschmann

Nonlinear interaction of a low density electron beam with a uniform plasma is studied using two-dimensional particle-in-cell (PIC) simulations. We focus on formation of coherent phase space structures in the case, when a wide…

Plasma Physics · Physics 2012-05-21 I. V. Timofeev

Filaments are ubiquitous in the universe. Recent observations have revealed that stars and star clusters form preferentially along dense filaments. Understanding the formation and properties of filaments is therefore a crucial step in…

Solar and Stellar Astrophysics · Physics 2016-01-22 Christoph Federrath