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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

We study temporal variations in the amplitudes and widths of high-degree acoustic modes by applying the ring-diagram technique to the GONG+, MDI and HMI Dopplergrams during the declining phase of cycle 23 and rising phase of cycle 24. The…

Solar and Stellar Astrophysics · Physics 2015-06-15 Olga Burtseva , Sushant Tripathy , Richard Bogart , Kiran Jain , Rachel Howe , Frank Hill , Maria Cristina Rabello-Soares

We apply time-distance helioseismology, local correlation tracking and Fourier spatial-temporal filtering methods to realistic supergranule scale simulations of solar convection and compare the results with high-resolution observations from…

Solar models computed with mass loss, microscopic diffusion of helium and heavy elements and with updated physics have been evolved from the pre-main sequence to present days; they are compared to the observational constraints including…

Astrophysics · Physics 2007-05-23 P. Morel , J. Provos , G. Berthomieu

We compared magnetograms from the KPVT/SPM, SoHO/MDI, SOLIS/VSM, and SDO/HMI with the aim of probing the effect on measured solar magnetism of the variation in instrument response with time, magnetogram signal level, and position on the…

Solar and Stellar Astrophysics · Physics 2024-05-24 K. L. Yeo , S. K. Solanki , N. A. Krivova

In this paper, we try to improve the magnetogram calibration method of the Solar Magnetic Field Telescope (SMFT). The improved calibration process fits the observed full Stokes information, using six points on the profile of Fe {\i} 5324.18…

Solar and Stellar Astrophysics · Physics 2014-09-18 Xianyong Bai , Yuanyong Deng , Fei Teng , Jiangtao Su , Xinjie Mao , Guoping Wang

Normal modes are coupled by the presence of perturbations in the Sun, providing a novel and under-appreciated helioseismic technique with which to image the solar interior. The process of measuring coupling between normal modes is…

Solar and Stellar Astrophysics · Physics 2018-07-18 Shravan Hanasoge

Current helicity and twist of solar magnetic fields are important quantities to characterize the dynamo mechanism working in the convection zone of the Sun. We have carried out a statistical study on the current helicity of solar active…

Solar and Stellar Astrophysics · Physics 2015-06-23 Kenichi Otsuji , Takashi Sakurai , Kirill Kuzanyan

Despite more than 40 years of research in condensed-matter physics, state-of-the-art approaches for simulating the radial distribution function (RDF) g(r) still rely on binning pair-separations into a histogram. Such methods suffer from…

Materials Science · Physics 2016-09-05 Thomas W. Rosch , Paul N. Patrone

We constrain the velocity spectral distribution of global-scale solar convective cells at depth using techniques of local helioseismology. We calibrate the sensitivity of helioseismic waves to large-scale convective cells in the interior by…

Solar and Stellar Astrophysics · Physics 2015-05-18 S. M. Hanasoge , T. L. Duvall , M. L. DeRosa

The consistency of time--distance inversions for horizontal components of the plasma flow on supergranular scales in the upper solar convection zone is checked by comparing the results derived using two k--\omega filtering procedures --…

Solar and Stellar Astrophysics · Physics 2015-06-16 Michal Svanda

Recently, we have discovered an error in our Monte-Carlo spectral fitting routine, more specifically where the errors on the fluxes were rescaled to get a reduced chi2 of 1. The rescaled errors were too big, resulting in too wide a range of…

Large-scale plasma flows in the Sun's convection zone likely play a major role in solar dynamics on decadal timescales. In particular, quantifying meridional motions is a critical ingredient for understanding the solar cycle and the…

Solar and Stellar Astrophysics · Physics 2015-06-19 Shukur Kholikov , Alexander Serebryanskiy , Jason Jackiewicz

Thanks to their high quality, new and upcoming asteroseismic observations - with CoRoT, Kepler, and from the ground... - can benefit from the experience gained with helioseismology. We focus in this paper on solar-like oscillations, for…

Astrophysics · Physics 2008-04-02 J. Ballot , T. Appourchaux , T. Toutain , M. Guittet

Time-distance helioseismology is a set of powerful tools to study features below the Sun's surface. Inverse methods are needed to interpret time-distance measurements, with many examples in the literature. However, techniques that utilize a…

Solar and Stellar Astrophysics · Physics 2020-10-14 Jason Jackiewicz

The detection of multiple mode harmonic kink oscillations in coronal loops enables to obtain information on coronal density stratification and magnetic field expansion using seismology inversion techniques. The inference is based on the…

Solar and Stellar Astrophysics · Physics 2015-06-15 I. Arregui , A. Asensio Ramos , A. J. Diaz

The Sun supports a rich spectrum of internal waves that are continuously excited by turbulent convection. The GONG network and the MDI/SOHO space instrument provide an exceptional data base of spatially-resolved observations of solar…

Solar and Stellar Astrophysics · Physics 2015-05-14 L. Gizon , A. C. Birch , H. C. Spruit

Previous studies have used magnetic energy and helicity spectra, the latter computed using the two-scale method, to search for signatures of mean-field dynamos. In this study, we compare cotemporal HMI and SOLIS magnetograms to illustrate…

Solar and Stellar Astrophysics · Physics 2025-05-02 G. Kishore , Nishant K. Singh

Since the first observations of solar oscillations, helioseismology has been one of the most successful fields of astrophysics. Data of high quality were obtained through the implementation of networks of ground-based observatories such as…

Solar and Stellar Astrophysics · Physics 2019-06-20 G. Buldgen , A. Noels , S. Salmon

Observations of the solar surface reveal the presence of flows with length scales of around $35$ Mm, commonly referred to as supergranules. Inferring the sub-surface flow profile of supergranules from measurements of the surface and…

Solar and Stellar Astrophysics · Physics 2016-08-03 Jishnu Bhattacharya , Shravan M. Hanasoge
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