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Related papers: Barycenter kinematics in Local Group analogues

200 papers

We explore mass estimation of the Local Group via the use of the simple, dynamical `timing argument' in the context of a variety of theories of dark energy and modified gravity: a cosmological constant, a perfect fluid with constant…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-14 Michael McLeod , Ofer Lahav

If properly calibrated, the shapes of galaxy clusters can be used to investigate many physical processes: from feedback and quenching of star formation, to the nature of dark matter. Theorists frequently measure shapes using moments of…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-11 David Harvey , Andrew Robertson , Sut-Ieng Tam , Mathilde Jauzac , Richard Massey , Jason Rhodes , Ian G. McCarthy

Comparing the gravitational acceleration induced on the Local Group of galaxies by different tracers of the underline density field we estimate, within the linear gravitational instability theory and the linear biasing ansatz, their…

Reducing theoretical uncertainties in Galactic dark matter (DM) searches is an important challenge as several experiments are now delving into the parameter space relevant to popular (particle or not) candidates. Since many DM signal…

Astrophysics of Galaxies · Physics 2020-10-20 Thomas Lacroix , Arturo Núñez-Castiñeyra , Martin Stref , Julien Lavalle , Emmanuel Nezri

Galactic bars are prominent dynamical structures within disk galaxies whose size, formation time, strength, and pattern speed influence the dynamical evolution of their hosts galaxies. Yet, their formation and evolution in a cosmological…

The observed velocities of the gas in barred galaxies are a combination of the azimuthally-averaged circular velocity and non-circular motions, primarily caused by gas streaming along the bar. These non-circular flows must be accounted for…

Astrophysics of Galaxies · Physics 2015-10-28 Toky Randriamampandry , Francoise Combes , Claude Carignan , Nathan Deg

(abridged) Predictions of the Concordance Cosmological Model (CCM) of the structures in the environment of large spiral galaxies are compared with observed properties of Local Group galaxies. Five new most probably irreconcilable problems…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 P. Kroupa , B. Famaey , K. S. de Boer , J. Dabringhausen , M. S. Pawlowski , C. M. Boily , H. Jerjen , D. Forbes , G. Hensler , M. Metz

A model for the mass in and around the Local Group previously used to fit redshifts of dwarf galaxies to their distances between 50 kpc and 2.6 Mpc under the condition of small and growing primeval departures from homogeneity is shown to…

Astrophysics of Galaxies · Physics 2017-08-16 P. J. E. Peebles

We present measurements of the radial gravitational acceleration around isolated galaxies, comparing the expected gravitational acceleration given the baryonic matter with the observed gravitational acceleration, using weak lensing…

We present a new set of high-resolution hydrodynamic cosmological zoom-in simulations that apply the Feedback In Realistic Environments (FIRE) physics to both Local Group (LG)-like and isolated Milky Way (MW)-like volumes (ten host systems…

We construct a Galacto-Local Group rotation curve, combining the Galactic rotation curve with a diagram, where galacto-centric radial velocities of outer globular clusters and member galaxies of the Local Group are plotted against their…

Astrophysics · Physics 2015-05-13 Yoshiaki Sofue

The local Hubble flow provides a valuable probe of the transition between cosmic expansion and nonlinear gravitational dynamics. On large scales, galaxies follow the linear Hubble law, but within group- and cluster-sized environments,…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-25 David Benisty , Antonino Del Popolo

Comparisons between observed and predicted strong lensing properties of galaxy clusters have been routinely used to claim either tension or consistency with $\Lambda$CDM cosmology. However, standard approaches to such cosmological tests are…

We use the Gaia data release 1 (DR1) to study the proper motion (PM) fields of the Large and Small Magellanic Clouds (LMC, SMC). This uses the Tycho-Gaia Astrometric Solution (TGAS) PMs for 29 Hipparcos stars in the LMC and 8 in the SMC.…

Astrophysics of Galaxies · Physics 2016-12-07 Roeland P. van der Marel , Johannes Sahlmann

Velocity bias is a reduction of the velocity dispersion of tracer galaxies in comparison to the velocity dispersion of the underlying mass field. There are two distinct forms of velocity bias. The single particle velocity reduction,…

Astrophysics · Physics 2008-02-03 Ray Carlberg

We study the cosmic peculiar velocity field as traced by a sample of 1184 spiral, elliptical and S0 galaxies, grouped in 704 objects. We carry out a statistical analysis, by calculating bulk flows and velocity correlation functions for this…

Astrophysics · Physics 2007-05-23 F. Lucchin , S. Matarrese , L. Moscardini , G. Tormen

We explore the potential of cross-correlating galaxies and peculiar velocities on non-linear scales to enhance cosmological constraints. Leveraging the \textsc{AbacusSummit} simulation suite and the halo occupation distribution (HOD)…

We propose a simple way to estimate the parameter beta = Omega_m^(0.6)/b from three-dimensional galaxy surveys. Our method consists in measuring the relation between the cosmological velocity and gravity fields, and thus requires peculiar…

Astrophysics · Physics 2011-02-11 Stéphane Colombi , Michał Chodorowski , Romain Teyssier

We present a study of the gas kinematics within the Hestia project, a state-of-the-art set of simulations of the Local Group, with a particular focus on the velocity patterns of different ions and the large-scale motion of gas and galaxies…

Astrophysics of Galaxies · Physics 2026-01-21 L. Biaus , S. E. Nuza , C. Scannapieco , P. Richter , M. Damle , N. I. Libeskind , M. Vogelsberger

From high resolution cosmological simulations of the Local Group in realistic environment, namely HESTIA simulations, we study the position and kinematic deviations that may arise between the disc of a Milky Way (or Andromeda)-like galaxy…

Astrophysics of Galaxies · Physics 2023-06-07 Jean-Baptiste Salomon , Noam Libeskind , Yehuda Hoffman