Zobrazeno 1 - 10
of 407
pro vyhledávání: '"Fedun, V."'
Autor:
Berretti, M., Stangalini, M., Verth, G., Jafarzadeh, S., Jess, D. B., Berrilli, F., Grant, S. D. T., Duckenfield, T., Fedun, V.
It is well known that the dominant frequency of oscillations in the solar photosphere is $\approx$3 mHz, which is the result of global resonant modes pertaining to the whole stellar structure. However, analyses of the horizontal motions of nearly 1 m
Externí odkaz:
http://arxiv.org/abs/2407.03950
Autor:
Jafarzadeh, S., Schiavo, L. A. C., Fedun, V., Solanki, S. K., Stangalini, M., Calchetti, D., Verth, G., Jess, D. B., Grant, S. D. T., Ballai, I., Gafeira, R., Keys, P. H., Fleck, B., Morton, R. J., Browning, P. K., Silva, S. A., Appourchaux, T., Gandorfer, A., Gizon, L., Hirzberger, J., Kahil, F., Suárez, D. Orozco, Schou, J., Strecker, H., Iniesta, J. C. del Toro, Valori, G., Volkmer, R., Woch, J.
Publikováno v:
A&A 688, A2 (2024)
Solar pores are intense concentrations of magnetic flux that emerge through the Sun's photosphere. When compared to sunspots, they are much smaller in diameter and hence can be impacted and buffeted by neighbouring granular activity to generate signi
Externí odkaz:
http://arxiv.org/abs/2404.18717
Autor:
Albidah, A. B., Fedun, V., Aldhafeeri, A. A., Ballai, I., Jess, D. B., Brevis, W., Higham, J., Stangalini, M., Silva, S. S. A., MacBride, C. D., Verth, G.
Through their lifetime sunspots undergo a change in their area and shape and, as they decay, they fragment into smaller structures. Here, for the first time we analyze the spatial structure of magnetohydrodynamic (MHD) slow body and fast surface mode
Externí odkaz:
http://arxiv.org/abs/2305.19418
Autor:
Grant, S. D. T., Jess, D. B., Stangalini, M., Jafarzadeh, S., Fedun, V., Verth, G., Keys, P. H., Rajaguru, S. P., Uitenbroek, H., Macbride, C. D., Bate, W., Gilchrist-Millar, C. A.
Solar pores are efficient magnetic conduits for propagating magnetohydrodynamic wave energy into the outer regions of the solar atmosphere. Pore observations often contain isolated and/or unconnected structures, preventing the statistical examination
Externí odkaz:
http://arxiv.org/abs/2209.06280
Here we study the nature and characteristics of waves propagating in partially ionised plasmas in the weakly ionised limit, typical for the lower part of the solar atmosphere. The framework in which the properties of waves are discussed depends on th
Externí odkaz:
http://arxiv.org/abs/2202.07387
Autor:
Albidah, A. B., Fedun, V., Aldhafeeri, A. A., Ballai, I., Brevis, W., Jess, D. B., Higham, J., Stangalini, M., Silva, S. S. A., Verth, G.
In this paper we provide clear direct evidence of multiple concurrent higher order magnetohydrodynamic (MHD) modes in circular and elliptical sunspots by applying both Proper Orthogonal Decomposition (POD) and Dynamic Mode Decomposition (DMD) techniq
Externí odkaz:
http://arxiv.org/abs/2202.00624
Autor:
Stangalini, M., Jess, D. B., Verth, G., Fedun, V., Fleck, B., Jafarzadeh, S., Keys, P. H., Murabito, M., Calchetti, D., Aldhafeeri, A. A., Berrilli, F., Del Moro, D., Jefferies, S. M., Terradas, J., Soler, R.
Publikováno v:
A&A 649, A169 (2021)
The umbral regions of sunspots and pores in the solar photosphere are generally dominated by $3$~mHz oscillations, which are due to $p$-modes penetrating the magnetic region. In these locations, wave power is also significantly reduced with respect t
Externí odkaz:
http://arxiv.org/abs/2103.11639
Slow magnetoacoustic waves in gravitationally stratified two-fluid plasmas in strongly ionised limit
The plasma dynamics at frequencies comparable with collisional frequency between various species has to be described in multi-fluid framework, where collisional interaction between particles is an important ingredient. In our study we will assume tha
Externí odkaz:
http://arxiv.org/abs/2012.05789
Autor:
Albidah, A. B., Brevis, W., Fedun, V., Ballai, I., Jess, D. B., Stangalini, M., Higham, J., Verth, G.
High resolution solar observations show the complex structure of the magnetohydrodynamic (MHD) wave motion. We apply the techniques of POD and DMD to identify the dominant MHD wave modes in a sunspot using the intensity time series. The POD technique
Externí odkaz:
http://arxiv.org/abs/2010.08530
Publikováno v:
The Astrophysical Journal, 897:153 (19 pp), 2020 July 14
Using numerical simulations, we study the effects of magnetic resistivity and thermal conductivity in the dynamics and properties of solar jets with characteristics of Type II spicules and cool coronal jets. The dynamic evolution of the jets is gover
Externí odkaz:
http://arxiv.org/abs/2005.13647