English
Related papers

Related papers: Scaling Laws and Temperature Profiles for Solar an…

200 papers

Context. The structure and heating of coronal loops are investigated since decades. Established scaling laws relate fundamental quantities like the loop apex temperature, pressure, length, and the coronal heating. Aims. We test such scaling…

Solar and Stellar Astrophysics · Physics 2017-09-19 Philippe-A. Bourdin , Sven Bingert , Hardi Peter

The solar atmosphere is dominated by loops of magnetic flux which connect the multi-million-degree corona to the much cooler chromosphere. The temperature and density structure of quasi-static loops is determined by the continuous flow of…

Solar and Stellar Astrophysics · Physics 2019-08-07 Stephen J. Bradshaw , A. Gordon Emslie , Nicolas H. Bian , Eduard P. Kontar

We study a series of relations between physical parameters in coronal loops of the quiet Sun reconstructed by combining tomographic techniques and modeling of the coronal magnetic field. We use differential emission measure tomography…

Solar and Stellar Astrophysics · Physics 2022-06-22 C. Mac Cormack , M. López Fuentes , C. H. Mandrini , D. G. Lloveras , M. Poisson , A. M. Vásquez

We examine the temperature structure of static coronal active region loops in regimes where thermal conductive transport is driven by Coulomb collisions, by turbulent scattering, or by a combination of the two. (In the last case collisional…

Solar and Stellar Astrophysics · Physics 2022-11-09 A. Gordon Emslie , Stephen J. Bradshaw

Context: The location of coronal heating in magnetic loops has been the subject of a long-lasting controversy: does it occur mostly at the loop footpoints, at the top, is it random, or is the average profile uniform? Aims: We try to address…

Astrophysics · Physics 2009-11-13 E. Buchlin , P. J. Cargill , S. J. Bradshaw , M. Velli

Recent coronal loop modeling has emphasized the importance of combining both Coulomb collisions and turbulent scattering to characterize field-aligned thermal conduction, which invokes a hybrid loop model. In this work we generalize the…

Solar and Stellar Astrophysics · Physics 2024-03-05 Y. Dai , J. J. Xiang , M. D. Ding

The scaling laws which relate the peak temperature $T_M$ and volumetric heating rate $E_H$ to the pressure $P$ and length $L$ for static coronal loops were established over 40 years ago; they have proved to be of immense value in a wide…

Solar and Stellar Astrophysics · Physics 2020-12-09 Stephen J. Bradshaw , A. Gordon Emslie

We report preliminary results from a series of numerical simulations of the reduced magnetohydrodynamic equations, used to describe the dynamics of magnetic loops in active regions of the solar corona. A stationary velocity field is applied…

Astrophysics · Physics 2009-10-31 Pablo Dmitruk , Daniel Gomez

Context. Photospheric motions shuffle the footpoints of the strong axial magnetic field that threads coronal loops giving rise to turbulent nonlinear dynamics characterized by the continuous formation and dissipation of field-aligned…

Solar and Stellar Astrophysics · Physics 2012-08-14 R. B. Dahlburg , G. Einaudi , A. F. Rappazzo , M. Velli

The evolution of a coronal loop is studied by means of numerical simulations of the fully compressible three-dimensional magnetohydrodynamic equations using the HYPERION code. The footpoints of the loop magnetic field are advected by random…

Solar and Stellar Astrophysics · Physics 2016-01-22 R. B. Dahlburg , G. Einaudi , B. D. Taylor , I. Ugarte-Urra , H. P. Warren , A. F. Rappazzo , M. Velli

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

Two recent works have analyzed a solar large and steady coronal loop observed with Yohkoh/SXT in two filter passbands to infer the distribution of the heating along it. Priest et al. (2000) modelled the distribution of the temperature…

Astrophysics · Physics 2009-11-07 F. Reale

Any successful model of coronal loops must explain a number of observed properties. For warm (~ 1 MK) loops, these include: 1. excess density, 2. flat temperature profile, 3. super-hydrostatic scale height, 4. unstructured intensity…

Solar and Stellar Astrophysics · Physics 2014-11-20 J. A. Klimchuk , J. T. Karpen , S. K. Antiochos

This work is prompted by the evidence of sharply peaked emission measure distributions in active stars, and by the claims of isothermal loops in solar coronal observations, at variance with the predictions of hydrostatic loop models with…

Astrophysics · Physics 2009-11-10 Paola Testa , Giovanni Peres , Fabio Reale

Stellar metallicity is a critical factor to characterize the stellar coronae because it directly affects the radiative energy loss from the atmosphere. By extending theoretical relations for solar coronal loops introduced by…

Solar and Stellar Astrophysics · Physics 2023-08-09 Haruka Washinoue , Takeru K. Suzuki

The heating of solar coronal loops is at the center of the problem of coronal heating. Given that the origin of the fast solar wind has been tracked down to atmospheric layers with transition region or even chromospheric temperatures, it is…

Solar and Stellar Astrophysics · Physics 2014-06-05 Bo Li , Haixia Xie , Xing Li , Li-Dong Xia

Despite decades of studying the Sun, the coronal heating problem remains unsolved. One fundamental issue is that we do not know the spatial scale of the coronal heating mechanism. At a spatial resolution of 1000 km or more it is likely that…

Solar and Stellar Astrophysics · Physics 2012-06-07 David H. Brooks , Harry P. Warren , Ignacio Ugarte-Urra

We model a coronal loop as a bundle of seven separate strands or filaments. Each of the loop strands used in this model can independently be heated (near their left footpoints) by Alfv\'en/ion-cyclotron waves via wave-particle interactions.…

Solar and Stellar Astrophysics · Physics 2014-11-20 S. Bourouaine , E. Marsch

Loop-aligned hydrodynamic modelings help better understand the thermodynamic evolution of flaring plasma confined in solar flare loops. Conventional loop modelings typically assume a uniform loop cross section. With a variation of the cross…

Solar and Stellar Astrophysics · Physics 2026-02-24 Yu Dai , Shihan Li , Wenlong Tang , Zhen Li , Mingde Ding

The Enthalpy Based Thermal Evolution of Loops (EBTEL) approximate model for static and dynamic coronal loops is developed to include the effect of a loop cross-sectional area which increases from the base of the transition region (TR) to…

Solar and Stellar Astrophysics · Physics 2021-11-19 P. J. Cargill , S. J. Bradshaw , J. A. Klimchuk , W. T. Barnes
‹ Prev 1 2 3 10 Next ›