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Related papers: Magnetic Braiding and Quasi-Separatrix Layers

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A reconnecting current layer is a `heart' of a solar flare, because it is a place of magnetic-field energy release. However there are no direct observations of these layers. The aim of our work is to understand why we actually do not…

Solar and Stellar Astrophysics · Physics 2014-04-18 A. V. Oreshina , I. V. Oreshina

We present observations and a magnetic-reconnection scenario of a twin pair of "atypical flares" that occurred on 2022 April 22 in a quadrupolar magnetic configuration formed by two active regions. The spatio-temporal evolution of the two…

Solar and Stellar Astrophysics · Physics 2026-03-04 Satyam Agarwal , Alphonse C. Sterling , Shibu K. Mathew , Ronald L. Moore , Qiang Hu , Ramit Bhattacharyya

The recent realization that Sweet-Parker current sheets are violently unstable to the secondary tearing (plasmoid) instability implies that such current sheets cannot occur in real systems. This suggests that, in order to understand the…

Solar and Stellar Astrophysics · Physics 2016-03-23 Dmitri A. Uzdensky , Nuno F. Loureiro

The existence of primordial magnetic fields can induce matter perturbations with additional power at small scales as compared to the usual $\Lambda$CDM model. We study its implication within the context of two-point shear correlation…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Kanhaiya L. Pandey , Shiv K. Sethi

The phenomenon of relaminarization is observed in many flow situations, including that of an initially turbulent boundary layer subjected to strong favourable pressure gradients. Available turbulence models have hitherto been unsuccessful…

Fluid Dynamics · Physics 2017-01-30 Rajesh Ranjan , Roddam Narasimha

It is generally considered that the emission of microwave zebra pattern (ZP) structures requires high density and high temperatures, which is similar to the situation of the flaring region where primary energy releases. Therefore, the…

Solar and Stellar Astrophysics · Physics 2015-06-11 Sijie Yu , Yihua Yan , Baolin Tan

We study five sequential solar flares (SOL2015-08-07) occurring in Active Region 12396 observed with the Goode Solar Telescope (GST) at the BBSO, complemented by IRIS and SDO observations. The main flaring region is an arch filament system…

Solar and Stellar Astrophysics · Physics 2018-03-19 Yingna Su , Rui Liu , Shangwei Li , Wenda Cao , Kwangsu Ahn , Haisheng Ji

Recent three-dimensional flare models suggest that flare-ribbon substructure is linked to the fragmentation of the reconnecting current sheet in the corona. Flare-ribbon substructure can therefore potentially serve as a unique diagnostic…

Forced magnetic reconnection, a reconnection event triggered by external perturbation, should be ubiquitous in the solar corona. Energy released during such cases can be much greater than that which was introduced by the perturbation. It is…

Solar and Stellar Astrophysics · Physics 2019-02-27 Max Potter , Philippa Browning , Mykola Gordovskyy

A weak fluctuating magnetic field embedded into a turbulent conducting medium grows exponentially while its characteristic scale decays. In the ISM and protogalactic plasmas, the magnetic Pr is very large, so a broad spectrum of growing…

Astrophysics · Physics 2008-11-26 Alexander Schekochihin , Steven Cowley , Jason Maron , Leonid Malyshkin

Reconnection physics at micro-scales is investigated in an electron magnetohydrodynamics frame. A new process of collapse of the neutral current sheet is demonstrated by means of analytical and numerical solutions. It shows how at scales…

Plasma Physics · Physics 2017-12-01 I F Shaikhislamov

Magnetic reconnection X-lines have been observed to be more common duskward of midnight. Thin current sheets have also been postulated to be a necessary precondition for reconnection onset. We take advantage of the MMS tetrahedral formation…

Space Physics · Physics 2021-12-10 A. J. Rogers , C. J. Farrugia , R. B. Torbert , T. J. Rogers

Magnetic fields and flows in coronal structures, for example, in gradual phases in flares, can be described by 2D and 3D magnetohydrostatic (MHS) and steady magnetohydrodynamic (MHD) equilibria. Within a physically simplified, but exact…

Solar and Stellar Astrophysics · Physics 2014-09-17 D. H. Nickeler , M. Karlicky , T. Wiegelmann , M. Kraus

We present the first statistical study of magnetic structures and associated energy dissipation observed during a single period of turbulent magnetic reconnection, by using the \textit{in-situ} measurements of the Magnetospheric Multiscale…

Space Physics · Physics 2020-10-28 K. Bergstedt , H. Ji , J. Jara-Almonte , J. Yoo , R. E. Ergun , L. -J. Chen

Twisted magnetic fields should be ubiquitous in flare-producing active regions where the magnetic fields are strongly non-potential. It has been shown that reconnection in helical magnetic coronal loops results in plasma heating and…

Solar and Stellar Astrophysics · Physics 2016-01-20 R. F. Pinto , M. Gordovskyy , P. K. Browning , N. Vilmer

Magnetic reconnection plays a crucial role in the energy release process for different kinds of solar eruptions and activities. The rapid solar eruption requires a fast reconnection model. Plasmoid instability in the reconnecting current…

Solar and Stellar Astrophysics · Physics 2024-05-01 Guanchong Cheng , Lei Ni , Zehao Tang , Yajie Chen , Yuhao Chen , Jialiang Hu , Jun Lin

Quasi-periodic pulsations (QPPs) are often observed in flare emissions. While these may reveal much about the time-dependent reconnection involved in flare energy release, the underlying mechanisms are still poorly understood. In this…

Solar and Stellar Astrophysics · Physics 2024-10-25 Luiz A. C. A. Schiavo , James Stewart , Philippa K. Browning

The manner in which the rate of magnetic reconnection scales with the Lundquist number in realistic three-dimensional (3D) geometries is still an unsolved problem. It has been demonstrated that in 2D rapid non-linear tearing allows the…

Plasma Physics · Physics 2015-06-19 P. F. Wyper , D. I Pontin

Rapidly rotating neutron stars blow a relativistic, magnetized wind mainly composed of electron-positron pairs. The free expansion of the wind terminates far from the neutron star where a weakly magnetized pulsar wind nebula forms, implying…

High Energy Astrophysical Phenomena · Physics 2017-11-29 Benoît Cerutti , Alexander A. Philippov

The problem of finding the optimal current distribution supported by small radiators yielding the minimum quality (Q) factor is a fundamental problem in electromagnetism. Q factor bounds constrain the maximum operational bandwidth of…