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Related papers: Dynamic Ly alpha jets

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The Sun produces highly dynamic and eruptive events that can drive shocks through the corona. These shocks can accelerate electrons, which result in plasma emission in the form of a type II radio burst. Despite the large number of type II…

Solar and Stellar Astrophysics · Physics 2021-03-10 Ciara A. Maguire , Eoin P. Carley , Pietro Zucca , Nicole Vilmer , Peter T. Gallagher

We present the first radio emission simulations from high resolution three dimensional relativistic hydrodynamic jets, which allow for a study of the observational implications of the interaction between the jet and external medium. This…

Aims: Changes of the magnetic field and the line-of-sight velocities in the photosphere are being reported for an M-class flare that originated at a $\delta$-spot belonging to active region NOAA 11865. Methods: High-resolution ground-based…

Studying the hemispheric distribution of active regions (ARs) with different magnetic morphology may clarify the features of the dynamo process that is hidden under the photospheric level. The magnetic flux data for 3047 ARs from the CrAO…

Solar and Stellar Astrophysics · Physics 2024-07-10 A. Zhukova

The radio lobes of the radio galaxy Hercules A contain intriguing ring-like structures concentric with the jet axis. To investigate the occurrence of such features, we have used hydrodynamic simulations of jets with a range of Mach numbers…

Astrophysics · Physics 2009-11-07 Curtis J. Saxton , Geoffrey V. Bicknell , Ralph S. Sutherland

Aims. To understand the morphology of the chromosphere in sunspot umbra. We investigate if the horizontal structures observed in the spectral core of the Ca II H line are ephemeral visuals caused by the shock dynamics of more stable…

Solar and Stellar Astrophysics · Physics 2015-02-11 V. M. J. Henriques , E. Scullion , M. Mathioudakis , D. Kiselman , P. T. Gallagher , F. P. Keenan

Super-Alfv\'enic jets, with kinetic energy densities significantly exceeding that of the solar wind, are commonly generated downstream of Earth's bow shock under both high and low beta plasma conditions. In this study, we present…

Space Physics · Physics 2024-08-16 Adnane Osmane , Savvas Raptis

The emergence of active regions (ARs) leads to various dynamic activities. Using high-resolution and long-lasting H$\alpha$ observations from the New Vacuum Solar Telescope, we report the dynamics of NOAA AR 12700 in its emerging phase on…

Solar and Stellar Astrophysics · Physics 2019-09-06 Sihui Zhong , Yijun Hou , Jun Zhang

We present observations and results of radiance and irradiance studies completed by SoHO-SUMER during the past solar cycle. We find that the cycle variation in Ly-alpha irradiance as observed by e.g. UARS-SOLSTICE can not be explained by…

Solar and Stellar Astrophysics · Physics 2010-02-19 W. Curdt , H. Tian

The variable magnetic field of the solar photosphere exhibits periodic reversals as a result of dynamo activity occurring within the solar interior. We decompose the surface field as observed by both the Wilcox Solar Observatory and the…

Solar and Stellar Astrophysics · Physics 2015-06-11 M. L. DeRosa , A. S. Brun , J. T. Hoeksema

Sunspot observations in chromospheric spectral lines have revealed the existence of short-lived linear bright transients, commonly referred to as penumbral micro-jets (PMJs). Details on the origin and physical nature of PMJs are to large…

Solar and Stellar Astrophysics · Physics 2019-06-19 Luc Rouppe van der Voort , Ainar Drews

We present an observational study of the plasma dynamics at the base of a solar coronal jet, using high resolution extreme ultraviolet imaging data taken by the Extreme Ultraviolet Imager on board Solar Orbiter, and by the Atmospheric…

Flares are known to restructure the magnetic field in the corona and to accelerate the gas between the field lines, but their effect on the photosphere is less well studied. New data of the Solar Optical Telescope (SOT) onboard Hinode…

Solar and Stellar Astrophysics · Physics 2010-07-02 Jun Zhang , Leping Li , S. K. Solanki

Solar differential rotation exhibits a prominent feature: its cyclic variations over the solar cycle, referred to as zonal flows or torsional oscillations, are observed throughout the convection zone. Given the challenge of measuring…

Solar and Stellar Astrophysics · Physics 2024-02-27 Krishnendu Mandal , Alexander G. Kosovichev , Valery V. Pipin

We have analyzed the parsec-scale jet kinematics of 447 bright radio-loud AGN, based on 15 GHz VLBA data obtained between 1994 August 31 and 2019 August 4. We present new total intensity and linear polarization maps obtained between 2017…

High Energy Astrophysical Phenomena · Physics 2021-12-14 M. L. Lister , D. C. Homan , K. I. Kellermann , Y. Y. Kovalev , A. B. Pushkarev , E. Ros , T. Savolainen

The Very high Angular resolution ULtraviolet Telescope (VAULT) is a sounding rocket payload built to study the crucial interface between the solar chromosphere and the corona by observing the strongest line in the solar spectrum, the Ly-a…

Solar and Stellar Astrophysics · Physics 2015-05-14 A. Vourlidas , B. Sánchez-Andrade Nuño , E. Landi , S. Patsourakos , L. Teriaca , U. Schühle , C. M. Korendyke , I. Nestoras

High-resolution Very-Long-Baseline Interferometry observations of relativistic jets are essential to constrain fundamental parameters of jet formation models. At a distance of 249 Mpc, Cygnus A is a unique target for such studies, being the…

High Energy Astrophysical Phenomena · Physics 2015-12-16 B. Boccardi , T. P. Krichbaum , U. Bach , F. Mertens , E. Ros , W. Alef , J. A. Zensus

The interaction between axion-like particles (ALPs) and photons induces ALP-photon oscillations in astrophysical magnetic fields, leading to spectral distortions in the $\gamma$-ray spectrum of blazars. The primary uncertainty of this…

High Energy Astrophysical Phenomena · Physics 2024-07-30 Lin-Qing Gao , Xiao-Jun Bi , Jun Li , Peng-Fei Yin

Observational evidence shows that coronal jets can hit prominences and set them in motion. The impact leads to large-amplitude oscillations (LAOs) of the prominence. In this paper we attempt to understand this process via 2.5D MHD numerical…

Solar and Stellar Astrophysics · Physics 2021-05-12 Manuel Luna , Fernando Moreno-Insertis