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Related papers: Galaxy infall models for arbitrary velocity direct…

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By correcting the redshift--dependent distances for peculiar motions through a number of peculiar velocity field models, we recover the true distances of a wide, all-sky sample of nearby galaxies (~ 6400 galaxies with velocities cz<5500…

Astrophysics · Physics 2009-10-30 C. Marinoni , P. Monaco , G. Giuricin , B. Costantini

We measure the three components of velocity dispersion, $\sigma_{R},\sigma_{\theta},\sigma_{\phi}$, for stars within 6 < R < 30 kpc of the Milky Way using a new radial velocity sample from the MMT telescope. We combine our measurements with…

Astrophysics of Galaxies · Physics 2015-11-11 Charles King , Warren R. Brown , Margaret J. Geller , Scott J. Kenyon

The first and second moments of stellar velocities encode important information about the formation history of the Galactic halo. However, due to the lack of tangential motion and inaccurate distances of the halo stars, the velocity moments…

Context. The environment plays a crucial role in galaxy evolution, particularly for galaxies infalling into clusters. Accurately estimating the infall times of galaxies from observations can significantly enhance our understanding of the…

Astrophysics of Galaxies · Physics 2025-07-02 Haoran Dou , Heng Yu

We consider the dynamics in and near galaxy clusters. Gas, dark matter and galaxies are presently falling into the clusters between approximately 1 and 5 virial radii. At very large distances, beyond 10 virial radii, all matter is following…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-08 L. Albaek , S. H. Hansen , D. Martizzi , B. Moore , R. Teyssier

We define a large sample of galaxies for use in a study of the fundamental plane in the intermediate redshift cluster CL1358+62 at $z=0.33$. We have analyzed high resolution spectra for 55 members of the cluster. The data were acquired with…

Astrophysics · Physics 2009-10-31 Daniel D. Kelson , Garth D. Illingworth , Pieter G. van Dokkum , Marijn Franx

The standard method of measuring the galaxy pairwise velocity dispersion on small scales is heavily weighted by the densest regions in a way that is difficult to calibrate. We propose a new statistic which measures the small-scale velocity…

Astrophysics · Physics 2009-10-30 Michael A. Strauss , Jeremiah P. Ostriker , Renyue Cen

Observations of the line-of-sight component of emitter velocities in galaxies are valuable for reconstructing their 2D velocity fields, albeit requiring certain assumptions. A common one is that radial flows can be neglected in the outer…

Astrophysics of Galaxies · Physics 2025-03-31 Francesco Sylos Labini , Giordano De Marzo , Matteo Straccamore

An analysis of large-area CO J=3-2 maps from the James Clerk Maxwell Telescope for 12 nearby spiral galaxies reveals low velocity dispersions in the molecular component of the interstellar medium. The three lowest luminosity galaxies show a…

We derive the central stellar velocity dispersion function for quiescent galaxies in 280 massive clusters with $\log (M_{200} / M_{\odot}) > 14$ in IllustrisTNG300. The velocity dispersion function is an independent tracer of the dark…

Astrophysics of Galaxies · Physics 2024-06-03 Jubee Sohn , Margaret J. Geller , Josh Borrow , Mark Vogelsberger

The systemic velocity or redshift of galaxies is a convenient tool to calculate their distances in the absence of primary methods, but the uncertainties on these flow distances may be substantial due to galaxy peculiar motions. Here, we…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-23 Konstantin Haubner , Federico Lelli , Enrico Di Teodoro , Francis Duey , Stacy McGaugh , James Schombert

We use the hydrodynamical galaxy formation simulations from the Illustris suite to study the origin and properties of galaxy velocity bias, i.e., the difference between the velocity distributions of galaxies and dark matter inside halos. We…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-31 Jia-Ni Ye , Hong Guo , Zheng Zheng , Idit Zehavi

We analyze the Illustris-1 hydrodynamical cosmological simulation to explore the stellar velocity dispersion of quiescent galaxies as an observational probe of dark matter halo velocity dispersion and mass. Stellar velocity dispersion is…

Astrophysics of Galaxies · Physics 2018-06-13 H. Jabran Zahid , Jubee Sohn , Margaret J. Geller

A new one-dimensional, inviscid, and vertically integrated disk model with prescribed infall is presented. The flow is computed using a second-order shock-capturing scheme. Included are vertical infall, radial infall at the outer radial…

Earth and Planetary Astrophysics · Physics 2022-07-19 Karim Shariff , Uma Gorti , Julio David Melon Fuksman

Galaxy groups likely to be virialized are identified within the CNOC2 intermediate redshift galaxy survey using an iterative method. The number-velocity dispersion relation is in agreement with the low-mass extrapolation of the cluster…

Massive star-forming regions with observed infall motions are good sites for studying the birth of massive stars. In this paper, 405 compact sources have been extracted from the APEX Telescope Large Area Survey of the Galaxy (ATLASGAL)…

Astrophysics of Galaxies · Physics 2015-06-24 Yu-Xin He , Jian-Jun Zhou , Jarken Esimbek , Wei-Guang Ji , Gang Wu , Xin-Di Tang , Ye Yuan , Da-Lei Li , W. A. Baan

We derive the mass weighted total density slopes within the effective (half-light) radius, $\gamma'$, for more than 2000 nearby galaxies from the SDSS-IV MaNGA survey using Jeans-anisotropic-models applied to IFU observations. Our galaxies…

The distributions of peculiar velocities of rich clusters and of groups of galaxies are investigated for different cosmological models and are compared with observations. Four cosmological models are studied: standard ($\Omega=1$) CDM,…

Astrophysics · Physics 2007-05-23 Neta A. Bahcall , Mirt Gramann , Renyue Cen

To study systematically the evolution on the angular extents of the galaxy, ICM, and dark matter components in galaxy clusters, we compiled the optical and X-ray properties of a sample of 340 clusters with redshifts $<0.5$, based on all the…

We use observations and simulation to study the relationship between star-forming galaxies and the intergalactic medium at z~3. The observed galaxy sample is based on spectroscopic redshift data from a combination of the VLT LBG Redshift…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-02 P. Tummuangpak , R. Bielby , T. Shanks , N. H. M. Crighton , H. Francke , L. Infante , T. Theuns