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Normal-mode helioseismic data analysis uses observed solar oscillation spectra to infer perturbations in the solar interior due to global and local-scale flows and structural asphericity. Differential rotation, the dominant global-scale…

Solar and Stellar Astrophysics · Physics 2021-03-30 Samarth G. Kashyap , Srijan Bharati Das , Shravan M. Hanasoge , Martin F. Woodard , Jeroen Tromp

Over the past two decades, helioseismology has revolutionized our understanding of the interior structure and dynamics of the Sun. Asteroseismology will soon place this knowledge into a broader context by providing structural data for…

Solar and Stellar Astrophysics · Physics 2009-06-16 T. S. Metcalfe , O. L. Creevey , J. Christensen-Dalsgaard

We present a new and highly efficient algorithm for computing a power spectrum made from evenly spaced data which combines the noise-reducing advantages of the weighted fit with the computational advantages of the Fast Fourier Transform…

Solar and Stellar Astrophysics · Physics 2015-05-28 S. T. Fletcher , A. -M. Broomhall , W. J. Chaplin , Y. Elsworth , R. New

We present a list of "best possible" estimates of low-degree p-mode frequencies, from 8640 days of observations made by the Birmingham Solar-Oscillations Network (BiSON). This is the longest stretch of helioseismic data ever used for this…

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

I describe and present the results of a newly developed fitting methodology optimized for very long time series. The development of this new methodology was motivated by the fact that we now have more than half a decade of nearly…

Astrophysics · Physics 2007-05-23 S. G. Korzennik

This report investigates the fitting of the Hessian or its inverse for stochastic optimizations using a Hessian fitting criterion derived from the preconditioned stochastic gradient descent (PSGD) method. This criterion is closely related…

Machine Learning · Statistics 2025-12-02 Xi-Lin Li

Models of solar-like oscillators yield acoustic modes at different frequencies than would be seen in actual stars possessing identical interior structure, due to modelling error near the surface. This asteroseismic "surface term" must be…

Solar and Stellar Astrophysics · Physics 2021-11-24 J. M. Joel Ong , Sarbani Basu , Mikkel N. Lund , Allyson Bieryla , Lucas S. Viani , David W. Latham

In this paper, we demonstrate a new method for fitting galaxy profiles which makes use of the full multi-wavelength data provided by modern large optical-near-infrared imaging surveys. We present a new version of GALAPAGOS, which utilises a…

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

Space-based observations of solar-like oscillations present an opportunity to constrain stellar models using individual mode frequencies. However, current stellar models are inaccurate near the surface, which introduces a systematic…

Solar and Stellar Astrophysics · Physics 2015-06-22 Warrick H. Ball , L. Gizon

Inferring interior properties of the Sun from photospheric measurements of the seismic wavefield constitutes the helioseismic inverse problem. Deviations in seismic measurements (such as wave travel times) from their fiducial values…

Solar and Stellar Astrophysics · Physics 2015-06-18 Shravan Hanasoge , Jeroen Tromp

We present an adaptation of the rotation-corrected, m-averaged spectrum technique designed to observe low signal-to-noise-ratio, low-frequency solar p modes. The frequency shift of each of the 2l+1 m spectra of a given (n,l) multiplet is…

Solar and Stellar Astrophysics · Physics 2011-02-11 D. Salabert , J. Leibacher , T. Appourchaux , F. Hill

The presence of mixed modes makes subgiants excellent targets for asteroseismology, providing a probe for the internal structure of stars. Here we study 36 \emph{Kepler} subgiants with solar-like oscillations and report their oscillation…

Solar and Stellar Astrophysics · Physics 2020-05-27 Yaguang Li , Timothy R. Bedding , Tanda Li , Shaolan Bi , Dennis Stello , Yixiao Zhou , Timothy R. White

We study the effect of localized sound-speed perturbations on global mode frequencies by applying techniques of global helioseismology on numerical simulations of the solar acoustic wave field. Extending the method of realization noise…

Astrophysics · Physics 2009-11-13 S. M. Hanasoge , T. P. Larson

In the standard (classic) approach, galaxy clustering measurements from spectroscopic surveys are compressed into baryon acoustic oscillations and redshift space distortions measurements, which in turn can be compared to cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-28 Samuel Brieden , Héctor Gil-Marín , Licia Verde

Since the advent of the space-based photometric missions such as CoRoT and NASA's Kepler, asteroseismology has acquired a central role in our understanding about stellar physics. The Kepler spacecraft, especially, is still releasing…

Instrumentation and Methods for Astrophysics · Physics 2017-11-29 Enrico Corsaro

At high frequencies beyond the acoustic cut-off, a peak-like structure is visible in the solar power spectrum. Known as the pseudo-modes, their frequencies have been shown to vary in anti-phase with solar magnetic activity. In this work, we…

Solar and Stellar Astrophysics · Physics 2024-09-06 Laura Jade Millson , Anne-Marie Broomhall , Tishtrya Mehta

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

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

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