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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

Helioseismology has provided unprecedented information about the internal rotation of the Sun. One of the important achievements was the discovery of two radial shear layers: one near the bottom of the convection zone (the tachocline) and…

Solar and Stellar Astrophysics · Physics 2015-06-23 Atefeh Barekat , Jesper Schou , Laurent Gizon

Low-degree solar p-mode observations from the long-lived Birmingham Solar Oscillations Network (BiSON) stretch back further than any other single helioseismic data set. Results from BiSON have suggested that the response of the mode…

Solar and Stellar Astrophysics · Physics 2018-07-18 R. Howe , W. J. Chaplin , G. R. Davies , Y. Elsworth , S. Basu , A. -M. Broomhall

NASA's Solar Dynamics Observatory is delivering vector field observations of the full solar disk with unprecedented temporal and spatial resolution; however, the satellite is in a highly inclined geostationary orbit. The relative…

Solar and Stellar Astrophysics · Physics 2016-06-01 P. W. Schuck , Spiro Antiochos , K. D. Leka , Graham Barnes

We compare four different methods of calculating uncertainty estimates in fitting parameterized models to RHESSI X-ray spectra, considering only statistical sources of error. Three of the four methods are based on estimating the scale-size…

Solar and Stellar Astrophysics · Physics 2015-06-15 Jack Ireland , Anne K. Tolbert , Richard A. Schwartz , Gordon D. Holman , Brian R. Dennis

The AMS02 experiment has published the periodic spectra of proton, helium and helium isotopes across the majority of the 24 solar cycle. These precise data exhibit temporal structures that correlate with solar modulation. In this study, we…

Solar and Stellar Astrophysics · Physics 2024-04-01 Wei-Cheng Long , Juan Wu

Magnetoseismology, a technique of magnetic field diagnostics based on observations of magnetohydrodynamic (MHD) waves, has been widely used to estimate the field strengths of oscillating structures in the solar corona. However, previously…

Solar and Stellar Astrophysics · Physics 2020-11-05 Zihao Yang , Hui Tian , Steven Tomczyk , Richard Morton , Xianyong Bai , Tanmoy Samanta , Yajie Chen

Context: The detection and identification of oscillation modes (in terms of their $\ell$, $m$ and successive $n$) is a great challenge for present and future asteroseismic space missions. The "peak tagging" is an important step in the…

Astrophysics · Physics 2009-11-11 P. Lambert , S. Pires , J. Ballot , R. A. Garcia , J. -L. Starck , S. Turck-Chieze

The multi-configurational self-consistent field theory is considered the standard starting point for almost all multireference approaches required for strongly-correlated molecular problems. The limitation of the approach is generally given…

Chemical Physics · Physics 2015-10-14 Robert E. Thomas , Qiming Sun , Ali Alavi , George H. Booth

In this paper, the minimization of computational cost on evaluating multi-dimensional integrals is explored. More specifically, a method based on an adaptive scheme for error variance selection in Monte Carlo integration (MCI) is presented.…

Numerical Analysis · Mathematics 2019-06-27 Felipe Carraro , Rafael Holdorf Lopez , Leandro Fleck Fadel Miguel , André Jacomel Torii

Using data from the Michelson Doppler Imager (MDI) instrument on board the Solar and Heliospheric Observatory (SOHO), we study the large-scale velocity fields in the outer part of the solar convection zone using the ring diagram technique.…

Astrophysics · Physics 2015-06-24 Sarbani Basu , H. M. Antia

The solar atmosphere is a dynamic environment, constantly evolving to form a wide range of magnetically dominated structures (coronal loops, spicules, prominences, etc.) which cover a significant percentage of the surface at any one time.…

Solar and Stellar Astrophysics · Physics 2013-06-06 R. Erdélyi , A. Hague , C. J. Nelson

Near-surface flows measured by the ring-diagram technique of local helioseismology show structures that persist over multiple rotations. We examine these phenomena using data from the {\em Global Oscillation Network Group} (GONG) and the…

Solar and Stellar Astrophysics · Physics 2015-08-19 R. Howe , R. W. Komm , D. Baker , L. Harra , L. van Driel-Gesztelyi , R. S. Bogart

The cosmic rays differential intensity inside the heliosphere, for energy below 30 GeV/nuc, depends on solar activity and interplanetary magnetic field polarity. This variation, termed solar modulation, is described using a 2-D (radius and…

Solar and Stellar Astrophysics · Physics 2015-06-12 P. Bobik , G. Boella , M. J. Boschini , C. Consolandi , S. Della Torre , M. Gervasi , D. Grandi , K. Kudela , S. Pensotti , P. G. Rancoita , D. Rozza , M. Tacconi

Helioseismic waves observable at the solar surface can be used to probe the properties of the Sun's interior. By measuring helioseismic travel times between different location on the surface, flows and other interior properties can be…

Solar and Stellar Astrophysics · Physics 2021-03-24 Thomas Hartlep , Junwei Zhao

The differential intensities of Cosmic Rays at Earth were calculated using a 2D stochastic Montecarlo diffusion code and compared with observation data. We evaluated the effect of stretched and compressed heliospheres on the Cosmic Ray…

Solar and Stellar Astrophysics · Physics 2017-08-23 P. Bobik , M. J. Boschini , C. Consolandi , S. Della Torre , M. Gervasi , D. Grandi , K. Kudela , F. Noventa , S. Pensotti , P. G. Rancoita , D. Rozza

The south-north travel-time differences are measured by applying time-distance helioseismology to the MDI and HMI medium-degree Dopplergrams covering May 1996-April 2017. Our data analysis corrects for several sources of systematic effects:…

Solar and Stellar Astrophysics · Physics 2018-11-14 Zhi-Chao Liang , Laurent Gizon , Aaron C. Birch , Thomas L. Duvall , S. P. Rajaguru

The inference of flows of material in the interior of the Sun is a subject of major interest in helioseismology. Here we apply techniques of Full Waveform Inversion (FWI) to synthetic data to test flow inversions. In this idealized setup,…

Solar and Stellar Astrophysics · Physics 2015-06-23 Shravan M Hanasoge

When using Hartree-Fock (HF) trial wave functions in quantum Monte Carlo calculations, one faces, in case of HF instabilities, the HF symmetry dilemma in choosing between the symmetry-adapted solution of higher HF energy and symmetry-broken…

Chemical Physics · Physics 2011-07-19 Peter Reinhardt , Julien Toulouse , Roland Assaraf , C. J. Umrigar , Philip E. Hoggan

We re-examine the deep-focus methodology of time-distance helioseismology previously used to estimate the power spectrum of the solar convection at a depth of about 30 Mm, which was found to be significantly weaker than predicted by theory…

Solar and Stellar Astrophysics · Physics 2026-02-11 John T. Stefan , Alexander G. Kosovichev , Gustavo Guerrero , Andrey M. Stejko