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Related papers: Dynamical History of the Local Group in $\Lambda$C…

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We present Hubble Space Telescope/WFPC2 images of eighteen galaxies situated in the vicinity of the Local Group (LG) as part of an ongoing snapshot survey of nearby galaxies. Their distances derived from the magnitude of the tip of the red…

The Local Group (LG) of galaxies is dominated by the M31 and Milky Way (MW) pair, a configuration which suggests that the mass distribution in the LG and its surroundings should be highly anisotropic. We use the APOSTLE cosmological…

Astrophysics of Galaxies · Physics 2023-10-05 Isabel M. E. Santos-Santos , Julio F. Navarro , Alan McConnachie

We place constraints on the dynamics of the Local Group (LG) by comparing the dipole of the Cosmic Microwave Background (CMB) with the peculiar velocity induced by the 2MRS galaxy sample. The analysis is limited by the lack of surveyed…

Astrophysics · Physics 2009-11-13 Abraham Loeb , Ramesh Narayan

I discuss Local Group galaxies from the perspective of external galaxies that define benchmark scaling relations. Making use of this information leads to a model for the Milky Way that includes bumps and wiggles due to spiral arms. This…

Astrophysics of Galaxies · Physics 2023-05-02 Stacy McGaugh

We analyze the velocity field of peripheral members of the Local Group. The Hubble flow at distances from 400 to 1400~kpc, formed by 7 of 11 nearby galaxies, is characterized by an extremely small line-of-sight velocity dispersion of 15…

Astrophysics of Galaxies · Physics 2025-06-11 Danila Makarov , Dmitry Makarov , Lidia Makarova , Noam Libeskind

The works in this portfolio test the hypothesis that it is not possible to extrapolate the Newtonian inverse square law of gravity from Solar System to galaxy scales. In particular, I look into various tests of Modified Newtonian Dynamics…

Astrophysics of Galaxies · Physics 2023-09-26 Indranil Banik

After recent systematic optical, IR, and HI surveys, the total number of known galaxies within 10 Mpc has increased from 179 to 550. About half this Local Volume (LV) sample is now been imaged with HST, yielding the galaxy distances with an…

Using N-body simulations of flat, dark energy dominated cosmologies, we show that galaxies around simulated binary systems resembling the Local Group (LG) have low peculiar velocities, in good agreement with observational data. We have…

Astrophysics · Physics 2009-11-10 Andrea V. Maccio' , Fabio Governato , Cathy Horellou

This paper explores the effect of the LMC on the mass estimates obtained from the timing argument. We show that accounting for the presence of the LMC systematically lowers the Local Group mass ($M_{\rm LG}$) derived from the relative…

Astrophysics of Galaxies · Physics 2015-12-02 Jorge Peñarrubia , Facundo A. Gómez , Gurtina Besla , Denis Erkal , Yin-Zhe Ma

We revisit the estimation of the combined mass of the Milky Way and Andromeda (M31), which dominate the mass of the Local Group. We make use of an ensemble of 30,190 halo pairs from the Small MultiDark simulation, assuming a $\Lambda$CDM…

Astrophysics of Galaxies · Physics 2017-12-27 Michael McLeod , Noam Libeskind , Ofer Lahav , Yehuda Hoffman

This article presents results of VLBI observations of regions of H2O maser activity in the Local Group galaxies M33 and IC10. Since all position measurements were made relative to extragalactic background sources, the proper motions of the…

Astrophysics · Physics 2015-05-13 A. Brunthaler , M. J. Reid , H. Falcke , C. Henkel , K. M. Menten

The total mass of the Local Group (LG) is a fundamental quantity that enables interpreting the orbits of its constituent galaxies and placing the LG in a cosmological context. One of the few methods that allows inferring the total mass…

It has been recently claimed that there is no correlation between the distribution of galaxies and their peculiar velocities within the Local Volume (LV), namely a sphere of R=7/h Mpc around the Local Group (LG). It has been then stated…

Astrophysics · Physics 2009-06-23 Luis A. Martinez-Vaquero , Gustavo Yepes , Yehuda Hoffman

We investigate the kinematic properties of gas and galaxies in the Local Group (LG) using high-resolution simulations performed by the {\sc Hestia} (High-resolution Environmental Simulations of The Immediate Area) collaboration. Our…

Based on accurate measurements of distances to nearby galaxies made with Hubble Space Telescope, we determined the radii of the zero-velocity surface: R_0 = 0.96+-0.03 Mpc for the Local Group and R_0 = 0.89+-0.05 Mpc for the group of…

Astrophysics · Physics 2007-05-23 I. D. Karachentsev , O. G. Kashibadze

We present a new way to identify systems similar to our Local Group (LG) of galaxies in cosmological simulations. Our method uses as a new constraint the speed and direction of the LG's center of mass, which we can measure accurately from…

Astrophysics of Galaxies · Physics 2026-03-12 I. A. López-Paredes , J. E. Forero-Romero

The kinematics of the Milky Way (MW) and M31, the dominant galaxies in the Local Group (LG), can be used to estimate the LG total mass. New results on the M31 proper motion have recently been used to improve that estimate. Those results are…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-21 J. E. Forero-Romero , D. Sierra-Porta

In this thesis, we use the motion of the Local Group of galaxies (LG) through the Universe to measure the cosmological parameter of non-relativistic matter density, Omega_m. For that purpose, we compare the peculiar velocity of the LG with…

Cosmology and Nongalactic Astrophysics · Physics 2012-05-10 Maciej Bilicki

Our goal is to estimate the mass of the Local Group (LG) and the individual masses of its primary galaxies, the M31 and the Milky Way (MW). We do this by means of a supervised machine learning algorithm, the gradient boosted decision trees…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-13 Edoardo Carlesi , Yehuda Hoffman , Noam Libeskind

The Local Group is a small galaxy cluster with the membership of 62 nearby galaxies including the Milky Way and M31. Although the Local Group has yet to be virialized, it interacts with the surrounding matter as one gravitationally bound…

Astrophysics · Physics 2008-11-07 Bomee Lee , Jounghun Lee