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相关论文: Nonextensivity in the Solar Neighborhood

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The aim of the analysis of data from the Gaia Space Observatory is to obtain kinematic parameters of the collective motion of stars in a part of our galaxy. This research is based on a statistical analysis of the motion of {$55,038,539$}…

星系天体物理 · 物理学 2025-02-18 Petr Zavada , Karel Píška

In this study, the nonlinear analysis of the sunspot index is embedded in the non-extensive statistical theory of Tsallis. The triplet of Tsallis, as well as the correlation dimension and the Lyapunov exponent spectrum were estimated for…

混沌动力学 · 物理学 2015-06-04 G. P. Pavlos , L. P. Karakatsanis , M. N. Xenakis

We discuss the distribution of radial velocities of galaxies belonging to the Local Group. Two independent samples of galaxies as well as several methods of reduction from the heliocentric to the galactocentric radial velocities are…

天体物理学 · 物理学 2016-08-30 Wlodzimierz Godlowski , Katarzyna Bajan , Piotr Flin

In this study it is shown that the Tsallis q-extended statistical theory was found efficient to describe faithfully the space plasmas statistics in every case, from the planetic magnetospheres, to solar corona and solar dynamics, as well as…

混沌动力学 · 物理学 2012-03-20 G. P. Pavlos

We present a mathematical analysis of the statistical parallax method. The method yields physical insight into the maximum-likelihood determinations of the luminosity and velocity distribution and enables us to conduct a vigorous Monte…

天体物理学 · 物理学 2008-02-03 Piotr Popowski , Andrew Gould

With particular attention to the recently postulated introduction of a non-extensive generalization of Boltzmann-Gibbs statistics, we study the long-term stellar dynamical evolution of self-gravitating systems on timescales much longer than…

天体物理学 · 物理学 2009-11-07 Atsushi Taruya , Masa-aki Sakagami

We present multifiber echelle radial velocity results for 551 stars in the Sextans dwarf spheroidal galaxy and identify 294 stars as probable Sextans members. The projected velocity dispersion profile of the binned data remains flat to a…

Context. Searching for extrasolar planets through radial velocity measurements relies on the stability of stellar photospheres. Aims. We aim at characterizing the statistical properties of magnetic activity cycles, and studying their impact…

太阳与恒星天体物理 · 物理学 2011-07-28 C. Lovis , X. Dumusque , N. C. Santos , F. Bouchy , M. Mayor , F. Pepe , D. Queloz , D. Ségransan , S. Udry

We analyze the internal velocity dispersions of a sample of 172 nearby galaxy clusters (z < 0.15), each of which has at least 30 available galaxy redshifts, and spans a large richness range. Cluster membership selection is based on…

天体物理学 · 物理学 2010-04-06 Dario Fadda , Marisa Girardi , Giuliano Giuricin , Fabio Mardirossian , Marino Mezzetti

We characterize empirically the radial diffusion of stars in the plane of a typical barred disk galaxy by calculating the local spatial diffusion coefficient and diffusion time-scale for bulge-disk-halo N-body self-consistent systems which…

星系天体物理 · 物理学 2015-05-30 Maura Brunetti , Cristina Chiappini , Daniel Pfenniger

We present theoretical calculations for the differential distribution of stellar orbital eccentricity for a sample of solar-neighbour halo stars. Two types of static, spherical gravitational potentials are adopted to define the eccentricity…

星系天体物理 · 物理学 2015-05-30 Kohei Hattori , Yuzuru Yoshii

Sixteen RR Lyrae variables from the QUEST survey that lie in the leading arm of the tidal stream from the Sagittarius dSph galaxy have been observed spectroscopically to measure their radial velocities and metal abundances. The systemic…

天体物理学 · 物理学 2007-05-23 A. Katherina Vivas , Robert Zinn , Carme Gallart

Rotational speed is an important physical parameter of stars and knowing the distribution of stellar rotational velocities is essential for the understanding stellar evolution. However, it cannot be measured directly but the convolution of…

天体物理仪器与方法 · 物理学 2015-06-18 Michel Cure , Diego F. Rial , Alejandra Christen , Julia Cassetti

Future Gaia and Legacy Survey of Space and Time data releases, together with wide area spectroscopic surveys, will deliver large samples of resolved binary stars with phase space coordinates, albeit with low-cadence. Given an eccentricity…

太阳与恒星天体物理 · 物理学 2022-11-14 David Benisty , N. Wyn Evans , Anne-Christine Davis

Radial velocity dispersion in spheroidal and elliptical galaxies, as a function of radial distance from the center of the galaxy, has been derived from Cosmological Special Relativity. For velocity dispersions in the outer regions of…

综合物理 · 物理学 2009-11-13 John G. Hartnett

While stellar rotation periods $P_\mathrm{rot}$ may be measured from broadband photometry, the photometric modulation becomes harder to detect for slower rotators, which could bias measurements of the long-period tail of the…

太阳与恒星天体物理 · 物理学 2021-12-22 Kento Masuda , Erik A. Petigura , Oliver J. Hall

Using a penalised maximum likelihood we estimate, for the first time, the velocity distribution of white dwarfs in the Solar neighbourhood. Our sample consists of 129 675 white dwarfs within 500 pc in Gaia Early Data Release 3 The white…

太阳与恒星天体物理 · 物理学 2022-02-17 Daniel Mikkola , Paul J. McMillan , David Hobbs , John Wimarsson

Accurate determination of the local dark matter density is important for understanding the nature and distribution of dark matter in the universe. This requires that the local velocity distribution is characterised correctly. Here, we…

星系天体物理 · 物理学 2015-08-06 Alex Büdenbender , Glenn van de Ven , Laura L. Watkins

We use an improved wavelet analysis technique to reconstruct the $(U,V,W)$ velocity distribution for $\sim 250000$ stars from Gaia DR2, residing in the solar neighborhood of $200$~pc. The 2D wavelet transforms for three bivariate…

太阳与恒星天体物理 · 物理学 2020-11-20 R. V. Baluev , V. Sh. Shaidulin , A. V. Veselova

We report the results of a statistical analysis of the space distribution of galaxies within distances about 300 Mpc using the 2MRS catalog, which contains redshifts of 43533 galaxies of the 2MASS all-sky IR survey. Because of the unique…

宇宙学与河外天体物理 · 物理学 2016-10-26 Daniil Tekhanovich , Yurij V. Baryshev