Related papers: GONG p-mode parameters through two solar cycles
Recent observations indicate that solar p-mode line profiles are not exactly Lorentzian, but rather exhibit varying amounts of asymmetry about their respective peaks. We analyze p-mode line asymmetry using both a simplified one-dimensional…
This paper presents an analysis of observational data on the p-mode spectrum of the star alpha Cen B and a comparison with theoretical computations of the stochastic excitation and damping of the modes. We find that at frequencies > 4500…
The solar rotation profile is well constrained down to about 0.25 R thanks to the study of acoustic modes. Since the radius of the inner turning point of a resonant acoustic mode is inversely proportional to the ratio of its frequency to…
We have analyzed changes in the acoustic oscillation eigenfrequencies measured over the past 7 years by the GONG, MDI and LOWL instruments. The observations span the period from 1994 to 2001 that corresponds to half a solar cycle, from…
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…
We describe a global parametric model for the observed power spectra of solar oscillations of intermediate and low degree. A physically motivated parameterization is used as a substitute for a direct description of mode excitation and…
We compute the p-mode oscillation frequencies and frequency splittings that arise in a two-dimensional model of the Sun that contains toroidal magnetic fields in its interior.
We report on the results of the latest solarFLAG hare-and-hounds exercise, which was concerned with testing methods for extraction of frequencies of low-degree solar p modes from data collected by Sun-as-a-star observations. We have used…
The eleven year solar cycle is known to affect the global modes of solar acoustic oscillations. In particular, p mode frequencies increase with solar activity. We propose a new method to detect the solar cycle from the p-mode…
Frequency and rotational splittings of the solar f-modes are estimated from the GONG data. Contrary to earlier observations the frequencies of f-modes are found to be close to the theoretically computed values for a standard solar model.…
Properties of stars undergoing pulsation such as the well known root-mean-density scaling relation can be useful when trying to match the observed properties of a particular star. It is often assumed that this relation is valid for p mode…
The solar-cyle variation of acoustic mode frequencies has a frequency dependence related to the inverse mode inertia. The discrepancy between model predictions and measured oscillation frequencies for solar and solar-type stellar acoustic…
The high-quality, full-disk helioseismic observations continuously collected by the spectrophotometer GOLF and the three photometers VIRGO/SPMs onboard the SoHO spacecraft for 17 years now (since April 11, 1996, apart from the SoHO…
Solar gravity modes (or g modes) -- oscillations of the solar interior for which buoyancy acts as the restoring force -- have the potential to provide unprecedented inference on the structure and dynamics of the solar core, inference that…
Sub-photospheric acoustic resonators allow for the formation of standing p-mode oscillations by reflecting acoustic waves with frequencies below the acoustic cut-off frequency. We employ the Klein-Gordon equation with a piecewise acoustic…
We use 9.5-yr of BiSON Sun-as-a-star data to search for dependence of solar-cycle parameter changes on the angular degree, l, of the data. The nature of the Sun-as-a-star observations is such that for changes measured at fixed frequency, or…
In solar-like oscillators, acoustic waves are excited by turbulent motion in the convective envelope and propagate inward, generating a variety of standing pressure modes. When combining together the power of several solar acoustic modes,…
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…
Manifestations of the solar magnetic activity through periodicities of about 11 and 2 years are now clearly seen in all solar activity indices.In this paper, we add information about the mechanism driving the 2 year period by studying the…
Accurate determination of the rotation rate in the radiative zone of the sun from helioseismic observations requires rotational frequency splittings of exceptional quality as well as reliable inversion techniques. We present here inferences…