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Related papers: The visibility of low-frequency solar acoustic mod…

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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

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

The observed power spectrum of high-degree solar p-modes (l>200) shows discrepancies with the power spectrum predicted by the stochastic excitement and damping theory. In an attempt to explain these discrepancies, the present paper is…

Astrophysics · Physics 2009-11-11 B. M. Shergelashvili , S. Poedts

We determine the frequencies of solar oscillations covering a wide range of degree (100< l <4000) and frequency (1.5 <\nu<10 mHz) using the ring diagram technique applied to power spectra obtained from MDI (Michelson Doppler Imager) data.…

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

The presence of intense magnetic fields in and around sunspots is expected to modify the solar structure and oscillation frequencies. Applying the ring diagram technique to data from the Michelson Doppler Imager (MDI) on board the Solar and…

Astrophysics · Physics 2009-11-07 S. P. Rajaguru , Sarbani Basu , H. M. Antia

We describe and use two different statistical approaches to try and detect low-frequency solar oscillations in Sun-as-a-star data: a frequentist approach and a Bayesian approach. We have used frequentist statistics to search contemporaneous…

Solar and Stellar Astrophysics · Physics 2015-05-18 A. -M. Broomhall , W. J. Chaplin , Y. Elsworth , T. Appourchaux , R. New

p-mode oscillations in solar-like stars are excited by the outer convection zone in these stars and reflected close to the surface. The p-modes are trapped inside an acoustic cavity, but the modes only stay trapped up to a given frequency…

Astrophysics · Physics 2009-11-13 C. Karoff

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…

We have used observations made with the helioseismic instrument LOWL collected over $\sim$ 6 years to carry out an independent study of the variations of the p-mode damping and excitation rates with solar activity. We observe significant…

Astrophysics · Physics 2008-11-26 D. Salabert , S. J. Jiménez-Reyes

Although it is well known that the solar acoustic mode frequency increases as the solar activity increases, the mechanism behind it is still unknown. Mode frequencies with 20 < l < 900 obtained by applying spherical harmonic decomposition…

Solar and Stellar Astrophysics · Physics 2015-05-27 M. Cristina Rabello-Soares

We introduce a new method to detect solar-like oscillations in frequency power spectra of stellar observations, under conditions of very low signal to noise. The Moving-Windowed-Power-Search, or MWPS, searches the power spectrum for…

Solar and Stellar Astrophysics · Physics 2015-06-11 Mikkel N. Lund , William J. Chaplin , Hans Kjeldsen

Efforts are underway to use high-precision timing of pulsars in order to detect low-frequency gravitational waves. A limit to this technique is the timing noise generated by dispersion in the plasma along the line of sight to the pulsar,…

High Energy Astrophysical Phenomena · Physics 2022-02-04 P. Kumar , S. M. White , K. Stovall , J. Dowell , G. B. Taylor

The observed solar p-mode velocity power spectra are compared with theoretically calculated power spectra over a range of mode degree and frequency. The shape of the theoretical power spectra depends on the depth of acoustic sources…

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

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…

Detection of solar gravity modes remains a major challenge to our understanding of the innerparts of the Sun. Their frequencies would enable the derivation of constraints on the core physical properties while their amplitudes can put severe…

Astrophysics · Physics 2009-11-13 K. Belkacem , R. Samadi , M. J. Goupil , M. A. Dupret , A. S. Brun , F. Baudin

The Birmingham Solar-Oscillations Network (BiSON) has been collecting data for over 30yrs and so observations span nearly three 11yr solar activity cycles. This allows us to address important questions concerning the solar cycle and its…

Astrophysics · Physics 2008-10-21 A. M. Broomhall , W. J. Chaplin , Y. Elsworth , R. New , G. A. Verner

In the present work we show robust indications of the existence of g modes in the Sun using 10 years of GOLF data. The present analysis is based on the exploitation of the collective properties of the predicted low-frequency (25 to 140…

Solar p-mode frequencies vary with solar activity. It is important to take this into account when comparing the frequencies observed from epochs that span different regions of the solar cycle. We present details of how to correct observed…

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

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

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…

Astrophysics · Physics 2011-02-11 W. J. Chaplin , G. Houdek , Y. Elsworth , R. New , T. R. Bedding , H. Kjeldsen
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