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Related papers: Why Are There Dwarf Spheroidal Galaxies?

200 papers

We study the chemical and kinematic properties of the first galaxies which formed at a high redshift, using high resolution cosmological numerical simulations, and compared them with the recent observational results for the Sculptor dwarf…

Astrophysics · Physics 2009-11-13 Daisuke Kawata , Nobuo Arimoto , Renyue Cen , Brad K. Gibson

The distribution of dark matter around galactic or cluster halos has usually been assumed to be approximately isothermal with a non-zero core radius, which is expected to be of the order of the size of the visible matter distribution.…

Astrophysics · Physics 2009-10-22 Ricardo A. Flores , Joel R. Primack

We use measurements of the stellar velocity dispersion profile of the Fornax dwarf spheroidal galaxy to derive constraints on its dark matter distribution. Though the data are unable to distinguish between models with small cores and those…

Context. In the Local Group, dwarf spheroidal galaxies (dSphs) and ultra-faint dwarf galaxies (UFDs) exhibit large velocity dispersions. These values are generally attributed to the presence of substantial amounts of dark matter (DM), in…

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…

General Physics · Physics 2009-11-13 John G. Hartnett

We compare the properties of dwarf galaxies in the Local Group with the simulated galaxies formed before reionization in a cosmological simulation of unprecedented spatial and mass resolution,including radiative feedback effects. We find…

Astrophysics · Physics 2009-11-10 Massimo Ricotti , Nickolay Y. Gnedin

Current explanation of the overabundance of dark matter subhalos in the Local Group (LG) indicates that there maybe a limit on mass of a halo, which can host a galaxy. This idea can be tested using voids in the distribution of galaxies: at…

Astrophysics · Physics 2015-05-13 Anton Tikhonov , Anatoly Klypin

We study the effects of black hole dark matter on the dynamical evolution of stars in dwarf galaxies. We find that mass segregation leads to a depletion of stars in the center of dwarf galaxies and the appearance of a ring in the projected…

Astrophysics of Galaxies · Physics 2017-08-08 Savvas M. Koushiappas , Abraham Loeb

Spiral structure (both flocculent and Grand Design types) is very rarely observed in dwarf galaxies because the formation of spiral arms requires special conditions. In this work we analyze the sample of about 40 dS-galaxies found by…

Astrophysics of Galaxies · Physics 2022-01-05 Anatoly V. Zasov , Alexander V. Khoperskov , Natalia A. Zaitseva , Sergey S. Khrapov

We construct axisymmetric mass models for dwarf spheroidal (dSph) galaxies in the Milky Way to obtain plausible limits on the non-spherical structure of their dark halos. This is motivated by the fact that the observed luminous parts of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Kohei Hayashi , Masashi Chiba

The existence of globular clusters (GCs) in a few satellite galaxies, and their absence in majority of dwarf galaxies, present a challenge for models attempting to understand the origins of GCs. In addition to GC presence appearing…

Astrophysics of Galaxies · Physics 2023-05-24 Yingtian Chen , Oleg Y. Gnedin

A simple and natural explanation for the dynamics and morphology of the Local Group Dwarf Spheroidal galaxies, Draco (Dra) and Ursa Minor (UMi), is that they are weakly unbound stellar systems with no significant dark matter component. A…

Astrophysics · Physics 2007-05-23 J. R. Kuhn , D. Kocevski , J. -J. Fleck

We present the results from a suite of N-body simulations of the tidal stripping of two-component dwarf galaxies comprising some stars and dark matter. We show that recent kinematic data from the local group dwarf spheroidal (dSph) galaxies…

Astrophysics · Physics 2009-11-11 J. I. Read , M. I. Wilkinson , N. Wyn Evans , G. Gilmore , Jan T. Kleyna

Gas-rich dwarf and disk galaxies overlap in numerous physical quantities that make their classification subjective. We report the discovery of a separation between dwarfs and disks into two unique sequences in the mass (luminosity) versus…

Astrophysics · Physics 2009-11-11 J. Schombert

We investigate whether the oblate, spheroidal morphology of common dwarf spheroidal galaxies (dSph) may result from the slow relaxation of stellar orbits within a halo of Wave Dark Matter ($\psi$DM) when starting from an initial disk of…

Astrophysics of Galaxies · Physics 2023-08-29 Riccardo Della Monica , Ivan de Martino , Tom Broadhurst

We investigate the present-day photometric properties of the dwarf spheroidal galaxies in the Local Group. From the analysis of their integrated colours, we consider a possible link between dwarf spheroidals and giant ellipticals. From the…

Astrophysics · Physics 2009-11-13 F. Calura , G. L. Lanfranchi , F. Matteucci , -

The fundamental manifold (FM), an extension of the fundamental plane formalism, incorporates all spheroid-dominated stellar systems from dwarf ellipticals up to the intracluster stellar populations of galaxy clusters by accounting for the…

Astrophysics · Physics 2009-11-11 Dennis Zaritsky , Anthony H. Gonzalez , Ann I. Zabludoff

Dwarf spheroidal galaxies have shallow central dark matter density profiles, low angular momentum and approximately exponential surface brightness distributions. Through N-body simulations and analytic calculations we investigate the extent…

Astrophysics · Physics 2009-11-10 J. I. Read , G. Gilmore

Recent high-resolution simulations of the formation of dark-matter halos have shown that the distribution of subhalos is scale-free, in the sense that if scaled by the velocity dispersion of the parent halo, the velocity distribution…

Astrophysics · Physics 2015-05-13 Tomoaki Ishiyama , Toshiyuki Fukushige , Junichiro Makino

Cold Dark Matter (CDM) has become the standard modern theory of cosmological structure formation. Its predictions appear to be in good agreement with data on large scales, and it naturally accounts for many properties of galaxies. But…

Astrophysics · Physics 2007-05-23 Joel R. Primack