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A 3D simulation of the upper part of the solar convective zone is used to derive constraints about the averaged and dynamic properties of solar turbulent convection. Theses constraints are then used to compute the acoustic energy supply…

天体物理学 · 物理学 2007-05-23 R. Samadi , A. Nordlund , R. F. Stein , M. J. Goupil , I. Roxburgh

Analyses of a 3D simulation of the upper layers of a solar convective envelope provide constraints on the physical quantities which enter the theoretical formulation of a stochastic excitation model of solar p modes, for instance the…

天体物理学 · 物理学 2009-11-07 R. Samadi , A. Nordlund , R. F. Stein , M. J. Goupil , I. Roxburgh

We extend semi-analytical computations of excitation rates for solar oscillation modes to those of other solar-like oscillating stars to compare them with recent observations. Numerical 3D simulations of surface convective zones of several…

天体物理学 · 物理学 2009-11-11 R. Samadi , D. Georgobiani , R. Trampedach R. , M. -J. Goupil , R. F. Stein , A. Nordlund

Turbulent motions in stellar convection zones generate acoustic energy, part of which is then supplied to normal modes of the star. Their amplitudes result from a balance between the efficiencies of excitation and damping processes in the…

天体物理学 · 物理学 2009-11-13 K. Belkacem , R. Samadi , M. J. Goupil , M. A. Dupret

Theoretical modeling of the driving processes of solar-like oscillations is a powerful way of understanding the properties of the convective zones of solar-type stars. In this framework, the description of the temporal correlation between…

太阳与恒星天体物理 · 物理学 2015-05-20 K. Belkacem , R. Samadi , M. J. Goupil , F. Baudin , D. Salabert , T. Appourchaux

Acoustic power and oscillation amplitudes of radial oscillations computed for a solar model are compared with solar seismic observations. The oscillations are assumed stochastically excited by turbulence. The numerical computations are…

天体物理学 · 物理学 2009-11-06 Reza Samadi , Marie-Jo Goupil , Yveline Lebreton

Detection of solar gravity modes remains a major challenge to our understanding of the innerparts of the Sun. Their frequencies would enable the derivation of constraints on the core physical properties while their amplitudes can put severe…

天体物理学 · 物理学 2009-11-13 K. Belkacem , R. Samadi , M. J. Goupil , M. A. Dupret , A. S. Brun , F. Baudin

The amplitude of solar p-mode oscillations is governed by stochastic excitation and mode damping, both of which take place in the surface convection zone. However, the time-dependent, turbulent nature of convection makes it difficult to…

太阳与恒星天体物理 · 物理学 2019-07-24 Yixiao Zhou , Martin Asplund , Remo Collet

The excitation rate P of solar p-modes is computed with a model of stochatic excitation which involves constraints on the averaged properties of the solar turbulence. These constraints are obtained from a 3D simulation. Resulting values for…

天体物理学 · 物理学 2007-05-23 R. Samadi , M. J. Goupil , Y. Lebreton , A. Nordlund , F. Baudin

We present a formalism for investigating the interaction between pmode oscillations and convection by analyzing realistic, three-dimensional simulations of the near-surface layers of the solar convection zone. By choosing suitable…

天体物理学 · 物理学 2009-10-31 Å. Nordlund , R. F. Stein

Solar p-mode oscillations exhibit a systematic offset towards higher frequencies due to shortcomings in the 1D stellar structure models, especially, the lack of turbulent pressure in the superadiabatic layers just below the optical surface,…

太阳与恒星天体物理 · 物理学 2016-07-06 Zazralt Magic , Achim Weiss

We have adapted the anelastic spectral code of Barranco & Marcus (2006) to simulate a turbulent convective layer with the intention of studying the effectiveness of turbulent eddies in dissipating external shear (e.g. tides). We derive the…

天体物理学 · 物理学 2015-05-13 Kaloyan Penev , Joseph Barranco , Dimitar Sasselov

Our recent study, based on a 3D numerical simulation, suggested that the stochastic excitation of solar p-modes has a non gaussian nature and a non gaussian model was proposed which results in a good agreement between the computed rate $P$…

天体物理学 · 物理学 2007-05-23 R. Samadi , A. Nordlund , R. F. Stein , M. J. Goupil , I. Roxburgh

As the amount of asteroseismic data available continues to grow, the inability to accurately model observed oscillation frequencies is becoming a critical problem for interpreting these frequencies. A major component of this problem is the…

太阳与恒星天体物理 · 物理学 2020-07-01 J. Schou , A. C. Birch

Hydrodynamical, 3D simulations of the outer layers of the Sun and Alpha Cen A are used to obtain constraints on the properties of turbulent convection in such stars. These constraints enable us to compute - on the base of a theoretical…

天体物理学 · 物理学 2007-05-23 R. Samadi , M. J. Goupil , F. Baudin , D. Georgobiani , R. Trampedach , R. Stein , A. Nordlund

The goal of this research is to investigate how magnetic field affects the dynamics of granular convection and excitation of solar oscillations by means of realistic numerical simulations. We have used a 3D, compressible, non-linear…

天体物理学 · 物理学 2008-05-27 L. Jacoutot , A. G. Kosovichev , A. Wray , N. N. Mansour

Differences between observed and theoretical eigenfrequencies of the Sun have characteristics which identify them as arising predominantly from properties of the oscillations in the vicinity of the solar surface: in the super-adiabatic,…

天体物理学 · 物理学 2007-05-23 C. S. Rosenthal , J. Christensen-Dalsgaard , A. Nordlund , R. F. Stein , R. Trampedach

The development of 2D and 3D simulations of solar convection has lead to a picture of convection quite unlike the usually assumed Kolmogorov spectrum turbulent flow. We investigate the impact of this changed structure on the dissipation…

天体物理学 · 物理学 2012-05-14 Kaloyan Penev , Dimitar Sasselov , Frank Robinson , Pierre Demarque

Solar p-mode oscillations are excited by the work of stochastic, non-adiabatic, pressure fluctuations on the compressive modes. We evaluate the expression for the radial mode excitation rate derived by Nordlund and Stein (Paper I) using…

天体物理学 · 物理学 2009-10-31 R. F. Stein , Å. Nordlund

Results of numerical 3D simulations of propagation of acoustic waves inside the Sun are presented. A linear 3D code which utilizes realistic OPAL equation of state was developed by authors. Modified convectively stable standard solar model…

天体物理学 · 物理学 2011-02-11 K. V. Parchevsky , A. G. Kosovichev
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