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Related papers: Sensitivity of helioseismic gravity modes to the d…

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We present our results concerning a systematical analysis of helioseismic implications on solar structure and neutrino production. We find Y$_{ph}=0.238-0.259$, $R_b/R_\odot=0.708-0.714$ and $\rho_b=(0.185-0.199)$ gr/cm$^3$. In the interval…

Astrophysics · Physics 2015-06-24 V. Castellani , S. Degl'Innocenti , W. A. Dziembowski , G. Fiorentini , B. Ricci

The asteroseismic modelling of period spacing patterns from gravito-inertial modes in stars with a convective core is a high-dimensional problem. We utilise the measured period spacing pattern of prograde dipole gravity modes (acquiring…

We present new results on the structure of the solar core, obtained with new sets of frequencies of solar low-degree p modes obtained from the BiSON network. We find that different methods used in extracting the different sets of…

Solar and Stellar Astrophysics · Physics 2009-07-22 Sarbani Basu , William J. Chaplin , Yvonne Elsworth , Roger New , Aldo M. Serenelli

To recover the flow information encoded in travel-time data of time-distance helioseismology, accurate forward modeling and a robust inversion of the travel times are required. We accomplish this using three-dimensional finite-frequency…

Astrophysics · Physics 2009-11-13 J. Jackiewicz , L. Gizon , A. C. Birch

Inversions for local helioseismology are an important and necessary step for obtaining three-dimensional maps of various physical quantities in the solar interior. Frequently, the full inverse problems that one would like to solve prove…

Solar and Stellar Astrophysics · Physics 2015-04-01 J. Jackiewicz , A. C. Birch , L. Gizon , S. M. Hanasoge , T. Hohage , J. -B. Ruffio , M. Svanda

Magnetic fields in the stellar interiors are key candidates to explain observed core rotation rates inside solar-like stars along their evolution. Recently, asteroseismic estimates of radial magnetic field amplitudes near the…

Solar and Stellar Astrophysics · Physics 2024-07-19 Shatanik Bhattacharya , Srijan Bharati Das , Lisa Bugnet , Subrata Panda , Shravan M. Hanasoge

Cosmic ray intensities (CRIs) recorded by sixteen neutron monitors have been used to study its dependence on the tilt angles (TA) of the heliospheric current sheet (HCS) during period 1976-2014, which covers three solar activity cycles 21,…

Space Physics · Physics 2017-08-21 M. A. El-Borie , S. A. Gwaily , A. A. Bishara

Local helioseismology has opened new frontiers in our quest for understanding of the internal dynamics and dynamo on the Sun. Local helioseismology reconstructs subsurface structures and flows by extracting coherent signals of acoustic…

Solar and Stellar Astrophysics · Physics 2016-07-20 Alexander G. Kosovichev , Junwei Zhao

We propose helioseismology as a new, precision probe of fifth forces at astrophysical scales, and apply it on the most general scalar-tensor theories for dark energy, known as Degenerate Higher-Order Scalar-Tensor theories (DHOST). We…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-11 Ippocratis D. Saltas , Ilídio Lopes

Helioseismology studies the structure and dynamics of the Sun's interior by observing oscillations on the surface. These studies provide information about the physical processes that control the evolution and magnetic activity of the Sun.…

Solar and Stellar Astrophysics · Physics 2015-05-27 Alexander G. Kosovichev

This article reviews some of the leading results obtained in solar dynamo physics by using temporal oscillator models as a tool to interpret observational data and dynamo model predictions. We discuss how solar observational data such as…

Solar and Stellar Astrophysics · Physics 2014-07-21 Ilídio Lopes , Dário Passos , Melinda Nagy , Kristof Petrovay

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

We compute f-mode travel-time sensitivity kernels for flows. Using a two-dimensional model, we show that it is important to account for several systematic effects, such as the foreshortening and the projection of the velocity vector onto…

Astrophysics · Physics 2007-05-23 J. Jackiewicz , L. Gizon , A. Birch

Time-distance helioseismology uses cross-covariances of wave motions on the solar surface to determine the travel times of wave packets moving from one surface location to another. We review the methodology to interpret travel-time…

Solar and Stellar Astrophysics · Physics 2015-08-19 Raymond Burston , Laurent Gizon , Aaron C. Birch

During the transition from solar cycle 23 to 24 from 2006 to 2009, the Sun was in an unusual solar minimum with very low activity over a long period. These exceptional conditions included a very low interplanetary magnetic field (IMF)…

High Energy Astrophysical Phenomena · Physics 2017-11-28 Jan Gieseler , Bernd Heber

We present a systematical analysis of uncertainties in the helioseismological determination of quantities characterizing the solar structure. We discuss the effect of errors on the measured frequencies, the residual solar model dependence…

Astrophysics · Physics 2009-10-28 S. Degl'Innocenti , W. A. Dziembowski , G. Fiorentini , B. Ricci

Helioseismic holography is a useful method to detect active regions on the Sun's far side and improve space weather forecasts. We aim to improve helioseismic holography by using a clear formulation of the problem, an accurate forward solver…

Solar and Stellar Astrophysics · Physics 2023-01-18 Dan Yang , Laurent Gizon , Hélène Barucq

When gravitational waves (GWs) from a spinning neutron star arrive from behind the Sun, they are subjected to gravitational lensing that imprints a frequency-dependent modulation on the waveform. This modulation traces the projected solar…

Solar and Stellar Astrophysics · Physics 2023-10-09 Ryuichi Takahashi , Soichiro Morisaki , Teruaki Suyama

(abridged) Context: Solar-like differential rotation is characterized by a rapidly rotating equator and slower poles. However, theoretical models and numerical simulations can result in a slower equator and faster poles when the rotation is…

Solar and Stellar Astrophysics · Physics 2014-10-17 P. J. Käpylä , M. J. Käpylä , A. Brandenburg

Helioseismology and solar modelling have enjoyed a golden era thanks to decades-long surveys from ground-based networks such as for example GONG, BiSON, IRIS and the SOHO and SDO space missions which have provided high-quality helioseismic…