Article
Astronomy & Astrophysics
K. Bora, R. Bhattacharyya, Avijeet Prasad, Bhuwan Joshi, Qiang Hu
Summary: This study uses Hall magnetohydrodynamics (HMHD) and magnetohydrodynamics (MHD) numerical simulations to analyze the magnetic reconnection process in a flaring solar active region. It finds that the HMHD simulation better matches the observations compared to the MHD simulation, opening up a new avenue for further exploration.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
K. Bora, R. Bhattacharyya, P. K. Smolarkiewicz
Summary: This study extends the computational model EULAG-MHD by incorporating Hall magnetohydrodynamics (HMHD) to explore fast magnetic reconnection at the ion inertial length scale. The results show that magnetic reconnections onset significantly earlier in HMHD simulations, leading to the development of magnetic flux ropes and tubes in three-dimensional evolution.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
M. Rempel, D. Przybylski
Summary: The paper discusses the transport processes of partially ionized plasmas and presents an implementation that retains the hyperbolic nature with small computational overhead for explicit integration. It examines the numerical formulations of ambipolar and Hall drift, showing that their combination can be applied to simulations of the solar chromosphere at minimal computational expense.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Shu-Di Yang, Liang Wang, Chuanfei Dong
Summary: This article reports the first fully kinetic simulations of collisionless reconnection in a three-species dusty plasma with negatively charged dust grains, discovering the double Hall pattern and analyzing the reconnection rate. This study is significant for explaining observations of planetary magnetospheres and astrophysical objects, as well as for laboratory studies of dusty plasmas.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
S. Y. Tang, Y. C. Zhang, L. Dai, T. Chen, C. Wang
Summary: This paper investigates the structure of out-of-plane magnetic field in a reconnection event observed at the magnetopause of the Earth magnetosphere, revealing the unique features of hexapolar Hall magnetic field and providing a comprehensive description of these features. The study offers significant evidence of the hexapolar Hall magnetic field in collisionless magnetic reconnection, providing insights into the Hall effect in such processes.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
R. L. Guo, Z. H. Yao, W. R. Dunn, B. Palmaerts, N. Sergis, D. Grodent, S. V. Badman, S. Y. Ye, Z. Y. Pu, D. G. Mitchell, B. Z. Zhang, N. Achilleos, A. J. Coates, Y. Wei, J. H. Waite, N. Krupp, M. K. Dougherty
Summary: Stunning aurorae are mainly produced by accelerated electrons colliding with the atmosphere along magnetic field lines. In Saturn's magnetosphere, a chain of paired currents is formed, generating separated auroral patches, indicating similarities with Earth's auroral current structures but with unique rotational characteristics due to Saturn's mass and energy sources.
ASTROPHYSICAL JOURNAL LETTERS
(2021)
Article
Physics, Multidisciplinary
K. Bora, Satyam Agarwal, Sanjay Kumar, R. Bhattacharyya
Summary: In this study, a novel Hall magnetohydrodynamics simulation is used to investigate the formation and evolution of a three-dimensional magnetic flux rope. It is found that the evolution of the flux rope is faster and more complex in the Hall magnetohydrodynamics simulation compared to the traditional magnetohydrodynamics simulation. The magnetic reconnections at null points in three-dimensional space play a significant role in the evolution of the flux rope.
Article
Physics, Fluids & Plasmas
Young Dae Yoon, Paul M. Bellan
Summary: This study reveals the origin of extreme and anomalous ion heating during magnetic reconnection, showing how the stochastic heating mechanism is responsible for this energization. The in-plane Hall electric fields not only accelerate ions, but also thermalize them through inducing chaotic motion.
PHYSICS OF PLASMAS
(2021)
Article
Astronomy & Astrophysics
Y. Zhong, Y. Dai, M. D. Ding
Summary: Recent observations in extreme-ultraviolet wavelengths have revealed a new late phase in some solar flares, with different production mechanisms such as long-lasting cooling or additional heating. Additionally, an enhancement of the envelope magnetic field above the active region may facilitate a more prompt and energetic heating of the late phase emissions.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Ying-Dong Jia, Yi Qi, San Lu, C. T. Russell
Summary: In this study, a three-dimensional Hall Magnetohydrodynamics (MHD) model is used to simulate the interaction of two entangled flux tubes and investigate how magnetic reconnection transforms them into new pairs under specific plasma conditions. The research shows the evolution and key parameters of this process, highlighting the importance of ambient plasma conditions for the completion of such interactions. The study supports the feasibility of reconnection between entangled flux tubes and quantifies how such structures evolve to modify the solar wind-geomagnetic field interaction.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2021)
Article
Physics, Fluids & Plasmas
W. Zhang, Z. W. Ma, H. W. Zhang
Summary: In this study, the nonlinear resistive-kink mode in low resistivity plasma in tokamak was investigated using a 3D, toroidal, nonlinear Hall-MHD code. It was discovered that the effect of two-fluid dynamics and toroidal flow can significantly alter the behavior of the resistive-kink mode, leading to a different evolution of magnetic islands and reconnection processes. Additionally, the investigation into the toroidal effect showed that the widths of the main m/n = 1/1 island and the secondary island slightly increase with increasing aspect ratios.
Article
Multidisciplinary Sciences
Julian Leonard, Sooshin Kim, Joyce Kwan, Perrin Segura, Fabian Grusdt, Cecile Repellin, Nathan Goldman, Markus Greiner
Summary: Strongly interacting topological matter exhibits new phenomena and has potential applications in quantum information technology. Fractional quantum Hall states, which arise from the interplay of a magnetic field and strong interactions, have been challenging to prepare in engineered systems. In this study, we realize a fractional quantum Hall state with ultracold atoms in an optical lattice, capturing many hallmark features of Laughlin-type states. Our work provides a starting point for exploring highly entangled topological matter with ultracold atoms.
Article
Multidisciplinary Sciences
Young Dae Yoon, Deirdre Wendel, Gunsu Yun
Summary: Although a continuous spectrum of current sheet equilibria exists, how a particular equilibrium is selected by a system remains unknown. This study reveals the exact process of equilibrium selection by analyzing the relaxation process of an unequilibrated current sheet with a finite guide field. The results demonstrate that the current sheet relaxes in a way that locally amplifies the guide field, leading to a mixed equilibrium. Comparisons with spacecraft observations and solar wind current sheet statistics show that such mixed equilibria are common and act as underlying local structures in various physical environments.
NATURE COMMUNICATIONS
(2023)
Article
Astronomy & Astrophysics
Changkun Li, Xianzhe Jia, Yuxi Chen, Gabor Toth, Hongyang Zhou, James A. Slavin, Weijie Sun, Gangkai Poh
Summary: Mercury possesses a dynamic magnetosphere primarily driven by the solar wind. Flux transfer events (FTEs) are frequently observed and are considered important for driving global convection at Mercury. Global simulations were conducted to study FTEs and their characteristics under different solar wind conditions. The simulations revealed notable dependence of FTE properties on solar wind conditions, consistent with previous observations.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Jaroslav Dudik, Guillaume Aulanier, Jana Kasparova, Marian Karlicky, Alena Zemanova, Juraj Lorincik, Miloslav Druckmuller
Summary: We report on the interaction between the legs of an erupting filament and associated P-SADs observed in 2012. Image processing techniques were used to enhance the features of this interaction. The results show that as the filament erupts, the legs stretch outwards and undergo a series of complex interactions, eventually leading to the appearance of P-SADs.
ASTROPHYSICAL JOURNAL LETTERS
(2022)