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Related papers: Nanoflare Diagnostics from Magnetohydrodynamic Hea…

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We present a comprehensive radiative magnetohydrodynamic simulation of the quiet Sun and large solar active regions. The 197 Mm wide simulation domain spans from 18 (10) Mm beneath the photosphere to 113 Mm in the solar corona. Radiative…

Solar and Stellar Astrophysics · Physics 2022-10-12 Feng Chen , Matthias Rempel , Yuhong Fan

Coronal heating refers to the physical processes that shape and structure the corona of the Sun and are responsible for its multi-million Kelvin temperatures. These processes are revealed in a number of different observational…

Solar and Stellar Astrophysics · Physics 2024-09-23 Iñigo Arregui , Tom Van Doorsselaere

Data-driven simulation is becoming an important approach for realistically characterizing the configuration and evolution of solar active regions, revealing the onset mechanism of solar eruption events and hopefully achieving the goal of…

Solar and Stellar Astrophysics · Physics 2023-01-25 Xinyi Wang , Chaowei Jiang , Xueshang Feng

Solar transients and eruptive phenomena which are ubiquitous in the solar atmosphere, can shed new light to the understanding of the outstanding problems like coronal heating and the solar wind acceleration. Observations in the entire…

Solar and Stellar Astrophysics · Physics 2011-10-05 Abhishek K. Srivastava , V. M. Nakariakov , B. N. Dwivedi , Pankaj Kumar

It was once thought that all coronal loops are in static equilibrium, but observational and modeling developments over the past decade have shown that this is clearly not the case. It is now established that warm (~1 MK) loops observed in…

Solar and Stellar Astrophysics · Physics 2009-04-09 James A. Klimchuk

We present a detailed analysis of a reflecting intensity perturbation in a large coronal loop that appeared as sloshing oscillation and lasted for at least one and a half periods. The perturbation is initiated by a microflare at one…

Solar and Stellar Astrophysics · Physics 2022-09-14 Fanxiaoyu Xia , Tongjiang Wang , Yang Su , Jie Zhao , Qingmin Zhang , Astrid M. Veronig , Weiqun Gan

Relaxation of braided coronal magnetic fields through reconnection is thought to be a source of energy to heat plasma in active region coronal loops. However, observations of active region coronal heating associated with an untangling of…

We simulate a coronal mass ejection (CME) using a three-dimensional magnetohydrodynamic (MHD) code that includes coronal heating, thermal conduction, and radiative cooling in the energy equation. The magnetic flux distribution at 1 R$_s$ is…

Solar and Stellar Astrophysics · Physics 2020-01-08 Katharine K. Reeves , Tibor Török , Zoran Mikić , Jon Linker , Nicholas A. Murphy

Nanoflares, the basic unit of impulsive energy release may produce much of the solar background emission. Extrapolation of the energy frequency distribution of observed microflares, which follows a power law to lower energies can give an…

Solar and Stellar Astrophysics · Physics 2011-12-22 E. Tajfirouze , H. Safari

Coronal jets are the captivating eruptions which are often found in the solar atmosphere, and primarily formed due to magnetic reconnection. Despite their short-lived nature and lower energy compared to many other eruptive events, e.g.…

Solar and Stellar Astrophysics · Physics 2024-09-06 Sushree S Nayak , Samrat Sen , Arpit Kumar Shrivastav , R. Bhattacharyya , P. S. Athiray

Standing long-period (with the periods longer than several minutes) oscillations in large hot (with the temperature higher than 3 MK) coronal loops have been observed as the quasi-periodic modulation of the EUV and microwave intensity…

Solar and Stellar Astrophysics · Physics 2016-06-15 Sanjay Kumar , V. M. Nakariakov , Y. -J. Moon

Context: Relaxation theory offers a straightforward method for estimating the energy that is released when a magnetic field becomes unstable, as a result of continual convective driving. Aims: We present new results obtained from nonlinear…

Solar and Stellar Astrophysics · Physics 2015-06-12 Michael Bareford , Alan Hood , Philippa Browning

The existence of the million-degree corona above the cooler photosphere is an unsolved problem in astrophysics. Detailed study of quiescent corona that exists regardless of the phase of the solar cycle may provide fruitful hints towards…

Solar and Stellar Astrophysics · Physics 2022-12-07 Vishal Upendran , Durgesh Tripathi , N. P. S. Mithun , Santosh Vadawale , Anil Bhardwaj

Without any doubt solar flaring loops possess a multi-thread internal structure that is poorly resolved and there are no means to observe heating episodes and thermodynamic evolution of the individual threads. These limitations cause…

Solar and Stellar Astrophysics · Physics 2015-11-04 R. Falewicz , P. Rudawy , K. Murawski , A. K. Srivastava

The dynamical coupling between the solar chromospheric plasma and magnetic field is investigated by numerically solving a fully self-consistent, two-dimensional initial-value problem for the nonlinear collisional MHD equations including…

Solar and Stellar Astrophysics · Physics 2015-12-09 L. M. Alekseeva , S. P. Kshevetskii

In this work we investigate the global activity patterns predicted from a model active region heated by distributions of nanoflares that have a range of frequencies. What differs is the average frequency of the distributions. The activity…

Solar and Stellar Astrophysics · Physics 2016-04-27 Stephen J. Bradshaw , Nicholeen M. Viall

The coronal heating problem is one of the most critical challenges in solar physics. Recent observations have revealed that small-scale swirls are ubiquitous in the photosphere and chromosphere, suggesting that they may play a significant…

Solar and Stellar Astrophysics · Physics 2025-08-21 Hidetaka Kuniyoshi , Shinsuke Imada , Takaaki Yokoyama

The High-resolution Coronal Imager (Hi-C) has provided Fe XII 193A images of the upper transition region moss at an unprecedented spatial (~0.3-0.4 arcsec) and temporal (5.5s) resolution. The Hi-C observations show in some moss regions…

The coronal heating problem remains one of the most challenging questions in solar physics. The energy driving coronal heating is widely understood to be associated with convective motions below the photosphere. Recent high-resolution…

Solar and Stellar Astrophysics · Physics 2025-03-21 Rui Wang , Yiming Jiao , Xiaowei Zhao , Chong Huang

Small-scale impulsive events, known as nanoflares, are thought to be one of the prime candidates that can keep the solar corona hot at its multi-million Kelvin temperature. Individual nanoflares are difficult to detect with the current…