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We make predictions of the detectability of low-frequency p modes. Estimates of the powers and damping times of these low-frequency modes are found by extrapolating the observed powers and widths of higher-frequency modes with large…

Astrophysics · Physics 2009-11-13 A. M. Broomhall , W. J. Chaplin , Y. Elsworth , S. T. Fletcher

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

Observations of the Sun with the LOWL instrument provide a homogeneous set of solar p-mode frequencies from low to intermediate degree which allows one to determine the structure of much of the solar interior avoiding systematic errors that…

The power spectrum, as a statistic in Fourier space, is commonly numerically calculated using the fast Fourier transform method to efficiently reduce the computational costs. To alleviate the systematic bias known as aliasing due to the…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-24 Yipeng Wang , Yu Yu

abridged] A method to rapidly estimate the Fourier power spectrum of a point distribution is presented. This method relies on a Taylor expansion of the trigonometric functions. It yields the Fourier modes from a number of FFTs, which is…

Astrophysics · Physics 2009-11-13 Stephane Colombi , Andrew H. Jaffe , Dmitri Novikov , Christophe Pichon

Measurements of line-of-sight dependent clustering via the galaxy power spectrum's multipole moments constitute a powerful tool for testing theoretical models in large-scale structure. Recent work shows that this measurement, including a…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-19 Nick Hand , Yin Li , Zachary Slepian , Uros Seljak

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 measuring the power spectrum of the distribution of large numbers of dark matter particles in simulations, or galaxies in observations, one has to use Fast Fourier Transforms (FFT) for calculational efficiency. However, because of the…

Astrophysics · Physics 2009-11-13 Weiguang Cui , Lei Liu , Xiaohu Yang , Yu Wang , Longlong Feng , Volker Springel

We present a new and up-to-date analysis of the solar low-degree $p$-mode parameter shifts from the Birmingham Solar-Oscillations Network (BiSON) over the past 22 years, up to the end of 2014. We aim to demonstrate that they are not…

Solar and Stellar Astrophysics · Physics 2015-11-04 R. Howe , G. R. Davies , W. J. Chaplin , Y. P. Elsworth , S. J. Hale

The Birmingham Solar Oscillations Network (BiSON) has provided high-quality high-cadence observations from as far back in time as 1978. These data must be calibrated from the raw observations into radial velocity and the quality of the…

Solar and Stellar Astrophysics · Physics 2014-09-01 G. R. Davies , W. J. Chaplin , Y. Elsworth , S. J. Hale

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

We describe a new spectrophotometer for the Birmingham Solar Oscillations Network (BiSON), based on a next generation observation platform, BiSON:NG, a significantly miniaturised system making use of inexpensive consumer-grade hardware and…

Instrumentation and Methods for Astrophysics · Physics 2022-12-12 S. J. Hale , W. J. Chaplin , G. R. Davies , Y. P. Elsworth , R. Howe

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

Estimators for $n$-point clustering statistics in Fourier-space demand that modern surveys of large-scale structure be transformed to Cartesian coordinates to perform Fast Fourier Transforms (FFTs). In this work, we explore this…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-05 Steven Cunnington , Laura Wolz

In order to take full advantage of the long time series collected by the GONG and MDI helioseismic projects, we present here an adaptation of the rotation-corrected $m$-averaged spectrum technique in order to observe low radial-order solar…

Astrophysics · Physics 2009-06-23 David Salabert , John W. Leibacher , Thierry Appourchaux

Radio interferometers observe the Fourier space of the sky, at locations determined by the array geometry. Before a real space image is constructed by a Fourier transform, the data is weighted to improve the quality of reconstruction. Two…

Instrumentation and Methods for Astrophysics · Physics 2015-06-22 Sarod Yatawatta

The estimation of power spectra from LDA data provides signal processing challenges for fluid dynamicists for several reasons: acquisition is dictated by randomly arriving particles, the registered particle velocities tend to be biased…

Fluid Dynamics · Physics 2019-06-14 Clara M. Velte , William K. George , Preben Buchhave

Mode fitting or "peak-bagging" is an important procedure in helioseismology allowing one to determine the various mode parameters of solar oscillations. Here we describe a way of reducing the systematic bias in the fits of certain mode…

Solar and Stellar Astrophysics · Physics 2011-02-11 S. T. Fletcher , W. J. Chaplin , Y. Elsworth , R. New

Hilbert-Huang Transform (HHT) is a novel data analysis technique for nonlinear and non-stationary data. We present a time-frequency analysis of both simulated light curves and an X-ray burst from the X-ray burster 4U 1702-429 with both the…

Astrophysics · Physics 2009-11-11 D. Han , S. N. Zhang

Quantitative helio- and asteroseismology require very precise measurements of the frequencies, amplitudes, and lifetimes of the global modes of stellar oscillation. It is common knowledge that the precision of these measurements depends on…

Astrophysics · Physics 2009-11-13 Thorsten Stahn , Laurent Gizon
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