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Related papers: Emerging Flux Simulations and Proto-Active Regions

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We analyze data from Hinode spacecraft taken over two 54-minute periods during the emergence of AR 11024. We focus on small-scale portions within the observed solar active region and discover the appearance of very distinctive small-scale…

Solar and Stellar Astrophysics · Physics 2015-03-13 S. Vargas Dominguez , L. van Driel-Gesztelyi , L. R. Bellot Rubio , .

Using the data on magnetic field maps and continuum intensity for Solar Cycles 23 and 24, we explored 100 active regions (ARs) that produced M5.0 or stronger flares. We focus on the presence/absence of the emergence of magnetic flux in…

Solar and Stellar Astrophysics · Physics 2024-02-29 Alexander S. Kutsenko , Valentina I. Abramenko , Andrei A. Plotnikov

Small-scale internetwork magnetic fields are important ingredients of the quiet Sun. In this paper we analyze how they appear and disappear on the solar surface. Using high resolution Hinode magnetograms, we follow the evolution of…

Solar and Stellar Astrophysics · Physics 2016-04-08 Milan Gošić , Luis R. Bellot Rubio , Jose Carlos Del Toro Iniesta , David Orozco Suárez , Yukio Katsukawa

Context: The expansion of network magnetic fields with height is a fundamental property of flux tube models. A rapid expansion is required to form a magnetic canopy. Aims: We characterize the observed expansion properties of magnetic…

Solar and Stellar Astrophysics · Physics 2015-05-19 A. Pietarila , R. Cameron , S. K. Solanki

We study the influence of a dynamo magnetic field on the buoyant rise and emergence of twisted magnetic flux-ropes, and their influence on the global external magnetic field. We ran 3D MHD numerical simulations using the ASH code and…

Solar and Stellar Astrophysics · Physics 2015-06-15 R. F. Pinto , A. S. Brun

Sunspot penumbrae show high-velocity patches along the periphery. The high-velocity downflow patches are believed to be the return channels of the Evershed flow. We aim to investigate their structure in detail using Hinode SOT/SP…

Solar and Stellar Astrophysics · Physics 2015-06-16 Michiel van Noort , Andreas Lagg , Sanjiv Tiwari , Sami Solanki

We report on the formation of small solar flares produced by patchy magnetic reconnection between interacting magnetic loops. A three-dimensional (3D) magnetohydrodynamic (MHD) numerical experiment was performed, where a uniform magnetic…

Solar and Stellar Astrophysics · Physics 2015-06-19 V. Archontis , V. Hansteen

We analyze a suite of thin sheet magnetohydrodynamical simulations based on the formulation of Basu, Ciolek, Dapp & Wurster. These simulations allow us to examine the observational consequences to a star-forming region of varying the input…

Solar and Stellar Astrophysics · Physics 2009-07-22 Helen Kirk , Doug Johnstone , Shantanu Basu

We studied the formation of a pore in AR NOAA 11462. We analysed data obtained with the IBIS at the DST on April 17, 2012, consisting of full Stokes measurements of the Fe I 617.3 nm lines. Furthermore, we analysed SDO/HMI observations in…

Solar and Stellar Astrophysics · Physics 2017-01-24 I. Ermolli , A. Cristaldi , F. Giorgi , F. Giannattasio , M. Stangalini , P. Romano , A. Tritschler , F. Zuccarello

Solar eruptive behavior is often modeled with magnetohydrodynamic simulations of magnetic flux emergence. The usual geometry considered is that of a horizontal cylindrical magnetic flux tube. An alternative is the toroidal tube geometry…

Solar and Stellar Astrophysics · Physics 2025-05-16 J. Zhuleku , V. Archontis , K. Moraitis

We have performed 3D MHD simulations to study the effect of partial ionization in the process of magnetic flux emergence in the Sun. In fact, we continue previous work and we now focus: 1) on the emergence of the magnetic fields above the…

Solar and Stellar Astrophysics · Physics 2024-12-17 Georgios Chouliaras , V. Archontis

Sunspots are concentrations of magnetic field on the visible solar surface that strongly affect the convective energy transport in their interior and surroundings. The filamentary outer regions (penumbrae) of sunspots show systematic radial…

Solar and Stellar Astrophysics · Physics 2009-07-17 M. Rempel , M. Schüssler , R. H. Cameron , M. Knölker

We investigate the evolution of subsurface flows during the emergence and the active phase of sunspot regions using the time-distance helioseismology analysis of the full-disk Dopplergrams from the Helioseismic and Magnetic Imager (HMI)…

Solar and Stellar Astrophysics · Physics 2024-12-25 Alexander G. Kosovichev , Viacheslav M. Sadykov

In the present work the instability of a flat horizontal thin layer of a magnetic fluid (the depth of no more than 50 \mum) under the action of a uniform magnetic field is studied experimentally. It was revealed that the development of…

Fluid Dynamics · Physics 2017-04-28 Arthur Zakinyan , Levon Mkrtchyan , Yuri Dikansky

Context: One aspect of understanding the dynamics of the quiet Sun is to quantify the evolution of the flux within small-scale magnetic features. These features are routinely observed in the quiet photosphere and were given various names,…

Solar and Stellar Astrophysics · Physics 2015-02-04 R. Attie , D. E. Innes

We analyze high-resolution spectropolarimetric observations of a flux emerging region (FER) in order to understand its magnetic and kinematic structure. Our spectropolarimetric observations in the He I 1083.0 nm spectral region of a FER are…

Context : Penumbrae are an important characteristic of sunspots, whose formation is intricately related to the nature of sub-photospheric magnetic fields. Aims : We study the formation of a penumbra in a decaying sunspot and compare its…

Solar and Stellar Astrophysics · Physics 2015-06-15 Rohan E. Louis , Shibu K. Mathew , Klaus G. Puschmann , Christian Beck , Horst Balthasar

We simulate the buoyant rise of a magnetic flux rope from the solar convection zone into the corona to better understand the energetic coupling of the solar interior to the corona. The magnetohydrodynamic model addresses the physics of…

Solar and Stellar Astrophysics · Physics 2015-06-03 Fang Fang , Ward Manchester , William P. Abbett , Bart van der Holst

The universe is magnetized on all scales probed so far. On the largest scales, galaxies and galaxy clusters host magnetic fields at the micro Gauss level coherent on scales up to ten kpc. Recent observational evidence suggests that even the…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-26 Kandaswamy Subramanian

Earlier observational studies have used the time evolution of emerging magnetic flux regions at the photosphere to infer their subsurface structures, assuming that the flux structure does not change significantly over the near-surface…

Solar and Stellar Astrophysics · Physics 2016-06-14 Chia-Hsien Lin , Yu-Chen Chen