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相关论文: Radiative zone solar magnetic fields and g-modes

200 篇论文

The sunspot penumbra is a transition zone between the strong vertical magnetic field area (sunspot umbra) and the quiet Sun. The penumbra has a fine filamentary structure that is characterized by magnetic field lines inclined toward the…

太阳与恒星天体物理 · 物理学 2010-12-02 I. N. Kitiashvili , A. G. Kosovichev , N. N. Mansour , A. A. Wray

We study the quiet Sun magnetic fields using spectropolarimetric observations of the infrared and visible Fe I lines at 6301.5, 6302.5, 15648 and 15653 A. Magnetic field strengths and filling factors are inferred by the simultaneous fit of…

天体物理学 · 物理学 2008-11-26 Itahiza Dominguez Cerdena , Jorge Sanchez Almeida , Franz Kneer

To explore the magnetic flux dispersion in the undisturbed solar photosphere, magnetograms acquired by Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamic Observatory (SDO) were utilized. Two areas, a coronal hole area (CH) and…

太阳与恒星天体物理 · 物理学 2017-09-07 Valentina Abramenko

Gravity modes in the Sun have been long searched during the past decades. Using their asymptotic properties Garcia et al. (2007) found the signature of the dipole g modes analyzing an spectral window between 25 and 140 muHz of velocity…

天体物理学 · 物理学 2008-10-10 A. Jimenez , R. A. Garcia

Turbulent magnetic fields fill most of the volume of the solar atmosphere. However, their spatial and temporal variations are still unknown. Since 2007, during the current solar minimum, we are periodically monitoring several wavelength…

太阳与恒星天体物理 · 物理学 2010-03-23 L. Kleint , S. V. Berdyugina , A. I. Shapiro , M. Bianda

We examine the excitation of unstable magnetosonic waves in the radiative envelopes of intermediate- and high-mass stars with a magnetic field of ~kG strength. Wind clumping close to the star and microturbulence can often be accounted for…

太阳与恒星天体物理 · 物理学 2018-04-04 Koushik Sen , Rodrigo Fernández , Aristotle Socrates

Helioseismic and magnetohydrodynamic waves are abundant in and above sunspots. Through cross-correlating oscillation signals in the photosphere observed by the SDO/HMI, we reconstruct how waves propagate away from virtual wave sources…

太阳与恒星天体物理 · 物理学 2015-08-19 Junwei Zhao , Ruizhu Chen , Thomas Hartlep , Alexander G. Kosovichev

We present evidence supporting wave reflection in the lower solar chromosphere based on helioseismic analysis of multi-height Doppler data. This evidence is derived through a wave propagation model that incorporates both upward- and…

太阳与恒星天体物理 · 物理学 2024-03-29 Varun Chaturmutha , Bernhard Fleck , Stuart Jefferies

Acoustic mode frequencies obtained by applying spherical harmonic decomposition to HMI, MDI and GONG observations were analysed throughout the solar cycle. Evidence of a deviation from a linear relation with solar radio flux was found…

太阳与恒星天体物理 · 物理学 2019-04-17 M. Cristina Rabello Soares

Understanding the magnetic connections from the Sun to interplanetary space is crucial for linking in situ particle observations with the solar source regions of the particles. A simple connection along the large-scale Parker spiral…

太阳与恒星天体物理 · 物理学 2023-02-08 T. Laitinen , S. Dalla , C. O. G. Waterfall , A. Hutchinson

The theory of magnetohydrodynamic (MHD) waves in solar coronal slabs in a zero-$\beta$ configuration and for parallel propagation of waves does not allow the existence of surface waves. When oblique propagation of perturbations is…

天体物理学 · 物理学 2009-11-13 I. Arregui , J. Terradas , R. Oliver , J. L. Ballester

A multi-line Bayesian analysis of the Zeeman broadening in the solar atmosphere is presented. A hierarchical probabilistic model, based on the simple but realistic Milne-Eddington approximation to the solution of the radiative transfer…

太阳与恒星天体物理 · 物理学 2015-06-18 A. Asensio Ramos

Analysis of f-mode frequencies has provided a measure of the radius of the Sun which is lower, by a few hundredths per cent, than the photospheric radius determined by direct optical measurement. Part of this difference can be understood by…

太阳与恒星天体物理 · 物理学 2023-10-18 M. Takata , D. O. Gough

Context. Solar gravity modes (g modes) are buoyancy waves trapped in the solar radiative zone that have been very difficult to detect at the surface. Solar g modes would complement solar pressure modes (p modes) in probing the central…

太阳与恒星天体物理 · 物理学 2019-09-04 Vincent G. A. Böning , Huanchen Hu , Laurent Gizon

We discuss some aspects of the propagation of high-energy cosmic rays (CRs) in turbulent magnetic fields, and propose a formula for the diffusion coefficient based on accurate simulations in a wide energy range. We discuss the transition…

天体物理学 · 物理学 2009-11-10 Etienne Parizot

We analyzed intermittency in the solar wind, as observed on the ecliptic plane, looking at magnetic field and velocity fluctuations between 0.3 and 1 AU, for both fast and slow wind and for compressive and directional fluctuations. Our…

天体物理学 · 物理学 2015-06-24 R. Bruno , V. Carbone , L. Sorriso-Valvo , B. Bavassano

We present numerical simulations of penetrative convection and gravity wave excitation in the Sun. Gravity waves are self-consistently generated by a convective zone overlying a radiative interior. We produce power spectra for gravity waves…

天体物理学 · 物理学 2009-11-13 Tamara M. Rogers , Gary A. Glatzmaier

In this review, our present day understanding of the Sun's global photospheric and coronal magnetic fields is discussed from both observational and theoretical viewpoints. Firstly, the large-scale properties of photospheric magnetic fields…

太阳与恒星天体物理 · 物理学 2015-06-12 D. H. Mackay , A. R. Yeates

In the present work we show robust indications of the existence of g modes in the Sun using 10 years of GOLF data. The present analysis is based on the exploitation of the collective properties of the predicted low-frequency (25 to 140…

We investigate the influence of cosmic magnetic fields on gravitational wave perturbations, and find exact solutions on large scales. We show that a large-scale magnetic field can generate large-scale non-decaying gravitational waves. In…

天体物理学 · 物理学 2009-11-06 Roy Maartens , Christos Tsagas , Carlo Ungarelli