Results 1 to 10 of about 253 (148)
VALIDATING TIME-DISTANCE HELIOSEISMOLOGY WITH REALISTIC QUIET-SUN SIMULATIONS [PDF]
The Astrophysical Journal, 2014 Linear time-distance helioseismic inversions are carried out for vector flow velocities using travel times measured from two $\sim 100^2\,{\rm Mm^2}\times 20\,{\rm Mm}$ realistic magnetohydrodynamic quiet-Sun simulations of about 20 hr. The goal is to test current seismic methods on these state-of-the-art simulations.
K. DeGrave, Jason Jackiewicz, M. Rempel
+6 more sources
Helioseismology: Listening to the inside of the sun [PDF]
The Journal of the Acoustical Society of America, 1993 The sun is oscillating in an intricate though gentle manner. The patterns of motion observed in the solar atmosphere are complicated, for they result from interference between about 107 resonant modes of oscillation of the interior. The sun possesses both acoustic p modes, for which pressure is the restoring force, and gravity g modes, for which ...
J. Toomre
openalex +2 more sources
DETECTION OF SUPERGRANULATION ALIGNMENT IN POLAR REGIONS OF THE SUN BY HELIOSEISMOLOGY [PDF]
The Astrophysical Journal, 2010 We report on a new phenomenon of `alignment' of supergranulation cells in the polar regions of the Sun. Recent high-resolution datasets obtained by the Solar Optical Telescope onboard the Hinode satellite enabled us to investigate supergranular structures in high-latitude regions of the Sun.
Kaori Nagashima +3 more
openalex +4 more sources
Local helioseismology and the active Sun [PDF]
Astronomische Nachrichten, 2010 AbstractThe goal of local helioseismology is to elicit three‐dimensional information about the sub‐surface (or far‐side) structure and dynamics of the Sun from observations of the helioseismic wave field at the surface. The physical quantities of interest include flows, sound‐speed deviations and magnetic fields. However, strong surface magnetic fields
H. Schunker
openalex +5 more sources
Light WIMPs in the Sun: Constraints from helioseismology [PDF]
Physical Review D, 2010 We calculate solar models including dark matter (DM) weakly-interacting massive particles (WIMPs) of mass 5-50 GeV and test these models against helioseismic constraints on sound speed, convection zone depth, convection zone helium abundance, and small separations of low-degree p-modes.
Daniel T. Cumberbatch +4 more
openalex +4 more sources
Helioseismology and p+p → d + e+ + νe in the sun [PDF]
Physics Letters B, 1998 By using a phenomenological field theory of nucleon-nucleon interactions, Oberhummer et al. found a cross section of p+p → d + e + + e about 2.9 times that given by the potential approach and adopted in Standard Solar Model calculations. We show that a solar model with S = 2.9SSSM is inconsistent with helioseismic data, the difference between model ...
S. Degl’Innocenti +2 more
openalex +4 more sources
Helioseismology: the Sun as a Strongly-Constrained, Weakly-Coupled Plasma [PDF]
International Astronomical Union Colloquium, 1994 AbstractAccurate measurements of observed frequencies of solar oscillations are providing a wealth of data on the properties of the solar interior. The frequencies depend on the solar structure, and on the properties of the plasma in the Sun. Except in the very outer layers, the stratification of the convection zone is almost adiabatic.
Werner Däppen
openalex +2 more sources
Helioseismology and screening of nuclear reactions in the Sun [PDF]
Physics Letters B, 2001 We show that models for screening of nuclear reactions in the Sun can be tested by means of helioseismology. As well known, solar models using the weak screening factors are in agreement with data. We find that the solar model calculated with the anti screening factors of Tsytovitch is not consistent with helioseismology, both for the sound speed ...
G. Fiorentini, B. Ricci, F.L. Villante
openalex +5 more sources
The Phanerozoic climate. [PDF]
Ann N Y Acad Sci, 2023 We review the long‐term climate variations during the last 540 million years (Phanerozoic Eon). We first summarize the geological and geochemical datasets available for reconstruction of long‐term climate variations. We then explore the main drivers of climate that appear to explain a large fraction of these climatic oscillations. The first is the long‐
Shaviv NJ, Svensmark H, Veizer J.
europepmc +2 more sources
Comparison of Large-Scale Flows on the Sun Measured by Time-Distance Helioseismology and Local Correlation Tracking [PDF]
Solar Physics, 2007 14 pages, 6 figures, just before acceptance in Solar ...
Michal Švanda +2 more
openalex +3 more sources