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Related papers: Low-Degree High-Frequency p and g Modes in the Sol…

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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…

Solar and Stellar Astrophysics · Physics 2023-10-18 M. Takata , D. O. Gough

We calculate the excitation of low frequency gravity waves by turbulent convection in the sun and the effect of the angular momentum carried by these waves on the rotation profile of the sun's radiative interior. We find that the gravity…

Astrophysics · Physics 2009-10-28 Pawan Kumar , Eliot J. Quataert

We study how rotation affects observable amplitudes of high-order g- and mixed r/g-modes and examine prospects for their detection and identification. Our formalism, which is described in some detail, relies on a nonadiabatic generalization…

Astrophysics · Physics 2007-05-23 J. Daszynska-Daszkiewicz , W. A. Dziembowski , A. A. Pamyatnykh

We investigate spatio-temporal evolution of high-degree acoustic mode frequencies of the Sun and the surface magnetic activity, over the course of multiple solar cycles, to improve our understanding of the connection between the solar…

Solar and Stellar Astrophysics · Physics 2023-12-20 Mackenzie A. Baird , Sushanta C. Tripathy , Kiran Jain

Retrograde waves with frequencies much lower than the rotation frequency become trapped in the solar radiative interior. The eigenfunctions of the compressible, nonadiabatic, Rossby-like modes ($\epsilon$-mechanism and radiative losses…

Astrophysics · Physics 2009-11-07 N. S. Dzhalilov , J. Staude , V. N. Oraevsky

The observed splittings of solar oscillation frequencies can be employed to separate the effects of internal solar rotation and to estimate the contribution from a large-scale magnetic field or any latitude-dependent thermal perturbation…

Astrophysics · Physics 2007-05-23 H. M. Antia , S. M. Chitre , M. J. Thompson

In the case of spatially-revolved helioseismic data (such as MDI, GONG, HMI), the usual mode-fitting analysis consists of fitting the 2l+1 individual m-spectra of a given multiplet (n, l) either individually or simultaneously. Such fitting…

Astrophysics · Physics 2008-10-13 D. Salabert , R. A. Garcia

Observations of the Sun with the LOWL instrument provide a homogeneous set of solar p-mode frequencies from low to intermediate degree which allows one to determine the structure of much of the solar interior avoiding systematic errors that…

Using intermediate degree p mode frequency data sets for solar cycle 22, we find that the frequency shifts and magnetic indices show a `hysteresis' phenomenon. It is observed that the magnetic indices follow different paths for the…

Astrophysics · Physics 2015-06-24 S. C. Tripathy , Brajesh Kumar , Kiran Jain , A. Bhatnagar

We carry out 3-D numerical simulations of the dynamical instability in rapidly rotating stars initially modeled as polytropes with n = 1.5, 1.0, and 0.5. The calculations are done with a SPH code using Newtonian gravity, and the…

General Relativity and Quantum Cosmology · Physics 2010-11-19 Janet L. Houser , Joan M. Centrella

Understanding the global rotational profile of the solar atmosphere and its variation is fundamental to uncovering a comprehensive understanding of the dynamics of the solar magnetic field and the extent of coupling between different layers…

Internal gravity waves have been observed in the Earth's atmosphere and oceans, on Mars and Jupiter, and in the Sun's atmosphere. Despite ample evidence for the existence of propagating gravity waves in the Sun's atmosphere, we still do not…

Solar and Stellar Astrophysics · Physics 2021-01-20 Daniele Calchetti , Stuart M. Jefferies , Bernhard Fleck , Francesco Berrilli , Dmitriy V. Shcherbik

With the ultimate aim of using the fundamental or $f$-mode to study helioseismic aspects of turbulence-generated magnetic flux concentrations, we use randomly forced hydromagnetic simulations of a piecewise isothermal layer in two…

Solar and Stellar Astrophysics · Physics 2015-06-19 Nishant K. Singh , Axel Brandenburg , S. M. Chitre , Matthias Rheinhardt

Using full-disk observations obtained with the Michelson Doppler Imager (MDI) on board the Solar and Heliospheric Observatory (SOHO) spacecraft, we present variations of the solar acoustic mode frequencies caused by the solar activity…

Astrophysics · Physics 2008-11-26 M. C. Rabello-Soares , S. G. Korzennik , J. Schou

Solar p-mode frequencies vary with solar activity. It is important to take this into account when comparing the frequencies observed from epochs that span different regions of the solar cycle. We present details of how to correct observed…

Solar and Stellar Astrophysics · Physics 2015-05-13 A. -M. Broomhall , W. J. Chaplin , Y. Elsworth , S. T. Fletcher , R. New

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…

Astrophysics · Physics 2009-11-13 K. Belkacem , R. Samadi , M. J. Goupil , M. A. Dupret , A. S. Brun , F. Baudin

The helioseismic Global Oscillation at Low Frequency (GOLF) and the Variability of solar Irradiance and Gravity Oscillations (VIRGO) instruments onboard SoHO, have been observing the Sun continuously for the last 14 years. In this…

Solar and Stellar Astrophysics · Physics 2015-03-17 R. A. Garcia , D. Salabert , J. Ballot , K. Sato , S. Mathur , A. Jimenez

A model-independent reconstruction of mechanical profiles (density, pressure) of the solar interior is outlined using the adiabatic sound speed and bouyancy frequency profiles. These can be inferred from helioseismology if both p- and…

Astrophysics · Physics 2009-10-31 Dallas C. Kennedy

We establish that global solar p-mode frequencies can be measured with sufficient precision on time scales as short as nine days to detect activity-related shifts. Using ten years of GONG data, we report that mode-mass and error-weighted…

Astrophysics · Physics 2009-02-10 S. C. Tripathy , F. Hill , K. Jain , J. W. Leibacher

We report our survey of $\gamma$\,Doradus stars from the 4-yr \textit{Kepler} mission. These stars pulsate mainly in g modes and r modes, showing period-spacing patterns in the amplitude spectra. The period-spacing patterns are sensitive to…

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