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Recent studies have established that peaks in solar oscillation power spectra are not Lorentzian in shape, but have a distinct asymmetry. Fitting a symmetric Lorentzian profile to the peaks therefore produces a shift in frequency of the…

Oscillation properties are usually measured by fitting symmetric Lorentzian profiles to the power spectra of Sun-like stars. However the line profiles of solar oscillations have been observed to be asymmetrical for the Sun. The physical…

Solar and Stellar Astrophysics · Physics 2018-05-02 O. Benomar , Mjo. Goupil , K. Belkacem , T. Appourchaux , M. B. Nielsen , M. Bazot , L. Gizon , S. Hanasoge , K. R. Sreenivasan , B. Marchand

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…

Astrophysics · Physics 2007-05-23 Pawan Kumar , Douglas Abrams

The observed solar oscillation spectrum is influenced by internal perturbations such as flows and structural asphericities. These features induce splitting of characteristic frequencies and distort the resonant-mode eigenfunctions. Global…

Solar and Stellar Astrophysics · Physics 2023-04-26 Srijan Bharati Das , Samarth G. Kashyap , Deniz Oktay , Shravan M. Hanasoge , Jeroen Tromp

Most helioseismic analyses are based on solar oscillations frequencies obtained by fitting symmetric peak profiles to the power spectra. However, it has now been demonstrated that the peaks are not symmetric. In this work we study the…

Astrophysics · Physics 2009-10-31 Sarbani Basu , H. M. Antia

We seek to address whether solar-cycle frequency shifts of the Sun's low-l p modes `distort' the underlying shapes of the mode peaks, when those peaks are observed in power frequency spectra made from data spanning large fractions, or more,…

Astrophysics · Physics 2009-11-13 W. J. Chaplin , Y. Elsworth , R. New , T. Toutain

Despite recent major advances, the opacity remains a source of substantial uncertainty in the calculation of solar models, and hence of solar oscillation frequencies. Hence it is of substantial interest to investigate the sensitivity of…

Astrophysics · Physics 2009-09-25 S. C. Tripathy , J. Christensen-Dalsgaard

Using the recently obtained GONG frequencies, we investigate the properties of the solar interior by constructing solar models with various input physics like opacities, equation of state, nuclear reaction rates etc. The differential…

Astrophysics · Physics 2007-05-23 S. C. Tripathy , H. M. Antia , F. Hill , A. Ambastha

The space-borne missions have provided us with a wealth of high-quality observational data that allows for seismic inferences of stellar interiors. This requires the computation of precise and accurate theoretical frequencies, but imperfect…

Solar and Stellar Astrophysics · Physics 2015-11-04 T. Sonoi , R. Samadi , K. Belkacem , H. -G. Ludwig , E. Caffau , B. Mosser

We used the m-averaged spectrum technique ("collapsogram") to extract the low-frequency solar p-mode parameters of low- and intermediate-angular degrees (l \leq 35) in long time series of GONG and MDI observations. Rotational splittings and…

Astrophysics · Physics 2008-11-12 D. Salabert , A. Eff-Darwich , R. Howe , S. G. Korzennik

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…

Astrophysics · Physics 2008-04-01 R. A. Garcia , S. Mathur , J. Ballot , A. Eff-Darwich , S. J. Jimenez-Reyes , S. G. Korzennik

We present results on the structure of the near-surface layers of the Sun obtained by inverting frequencies of high-degree solar modes from "ring diagrams". We have results for eight epochs between June 1996 and October 2003. The…

Astrophysics · Physics 2008-11-26 Sarbani Basu , H. M. Antia , Richard S. Bogart

Analyses of recent helioseismic data have produced ample evidence for substantial dynamical variation of the differential rotation within the solar convection zone. Given the inevitable difficulties in resolving the precise nature of…

Astrophysics · Physics 2009-11-10 Eurico Covas , David Moss , Reza Tavakol

The sense of line asymmetry of solar p-modes in the intensity power spectra is observed to be opposite of that seen in the velocity power spectra. Theoretical calculations provide a good understanding and fit to the observed velocity power…

Astrophysics · Physics 2009-10-30 Pawan Kumar , Sarbani Basu

The amplitude of density turbulence in the extended solar corona, especially near the dissipation scale, impinges on several problems of current interest. Radio sources observed through the turbulent solar wind are broadened due to…

Solar and Stellar Astrophysics · Physics 2015-06-23 M. Ingale , P. Subramanian , Iver Cairns

Measurements of oscillation frequencies of the Sun and stars can provide important independent constraints on their internal structure and dynamics. Seismic models of these oscillations are used to connect structure and rotation of the star…

Solar and Stellar Astrophysics · Physics 2015-05-18 Jishnu Bhattacharya , Shravan. M. Hanasoge , H. M. Antia

We use the three-dimensional hydrodynamic code of Stein and Nordlund to realistically simulate the upper layers of the solar convection zone in order to study physical characteristics of solar oscillations. Our first result is that the…

Astrophysics · Physics 2009-10-31 D. Georgobiani , A. G. Kosovichev , R. Nigam , A. Nordlund , R. F. Stein

The observed solar p-mode frequencies provide a powerful diagnostic of the internal structure of the Sun and permit us to test in considerable detail the physics used in the theory of stellar structure. Amongst the most commonly used…

Astrophysics · Physics 2009-10-31 M. C. Rabello-Soares , Sarbani Basu , J. Christensen-Dalsgaard

Ring diagram analysis can be used to study large scale velocity fields in the outer part of the solar convection zone. All previous works assume that the peak profiles in the solar oscillation power spectrum are symmetric. However, it has…

Astrophysics · Physics 2009-10-31 Sarbani Basu , H. M. Antia

Frequencies of intermediate-degree f-modes of the Sun seem to indicate that the solar radius is smaller than what is normally used in constructing solar models. We investigate the possible consequences of an error in radius on results for…

Astrophysics · Physics 2009-10-30 Sarbani Basu
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