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Using the HST archive WFPC2 observations and rotation curves measeured by Vogt et al. (1996), we constructed self-consistent light and mass distribution models for three disk galaxies at redshifts z = 0.15, 0.90 and 0.99. The models consist…

Astrophysics · Physics 2008-11-26 Antti Tamm , Peeter Tenjes

Milky Way (MW) satellites reside within dark matter (DM) subhalos with a broad distribution of circular velocity profiles. This diversity is enhanced with the inclusion of ultra-faint satellites, which seemingly have very high DM densities,…

Astrophysics of Galaxies · Physics 2019-09-25 Jesús Zavala , Mark R. Lovell , Mark Vogelsberger , Jan D. Burger

(Abridged) Axisymmetric models of the Milky Way exhibit strong interrelations between the Galactic constants (R_0 and T_0), the stellar columndensity (S_*) and the shape of the dark matter (DM) halo. Here we present analytical relations…

Astrophysics · Physics 2009-11-06 R. P. Olling , M. R. Merrifield

Abridged: We estimate the distances to ~48 million stars detected by the Sloan Digital Sky Survey and map their 3D number density distribution in 100 < D < 20 kpc range over 6,500 deg^2 of sky. The data show strong evidence for a Galaxy…

Recently, \cite{vanDokkum2018} have presented an important discovery of an ultra diffuse galaxy, NGC1052-DF2, with a dark matter content significantly less than predicted from its stellar mass alone. The analysis relies on measured radial…

Astrophysics of Galaxies · Physics 2019-01-03 Adi Nusser

In the present paper we derive the density distribution of dark matter (DM) in a well-observed nearby disc galaxy, the Andromeda galaxy. From photometrical and chemical evolution models constructed in the first part of the study (Tamm,…

Astrophysics · Physics 2008-09-02 Elmo Tempel , Antti Tamm , Peeter Tenjes

The failure of standard cosmolocical models in accounting for the statistics of dwarf satellites and the rotation curve of gas-rich dwarf galaxies in detail has led us to examine whether earlier non-equilibrium models of dwarf spheroidal…

Astrophysics · Physics 2009-11-07 Ralf Klessen , HongSheng Zhao

This is the second in a series of papers presenting a new calculation of the mass of the Galaxy based on radial velocities and distances for a sample of faint 16 < B < 21.3 field blue horizontal-branch (BHB) stars. We present accurate BV…

Astrophysics · Physics 2008-11-26 L. Clewley , S. J. Warren , P. C. Hewett , John E. Norris , N. W. Evans

The Gaia HR diagram shows the presence of apparently young stars at high tangential velocities. Using a simple analytical model I show that these stars are likely to be blue stragglers. Once normalized to red giant stars, the fraction of…

Astrophysics of Galaxies · Physics 2020-06-17 Luca Casagrande

The fact that dark matter (DM), thus far, has revealed itself only on scales of galaxies and larger, again thrusts onto astrophysics the opportunity and the responsibility to confront the age old mystery "What is the nature of matter?" By…

For a compiled sample of disk galaxies with available photometry (B and K bands), velocity line-widths and HI integral fluxes, several parameters which trace the luminous, baryonic and dark matter contents were inferred. We investigated how…

Astrophysics · Physics 2009-11-07 J. Zavala , V. Avila-Reese , H. Hernandez-Toledo , C. Firmani

We announce the discovery of the Aquarius~2 dwarf galaxy, a new distant satellite of the Milky Way, detected on the fringes of the VST ATLAS and the SDSS surveys. The object was originally identified as an overdensity of Red Giant Branch…

Astrophysics of Galaxies · Physics 2016-08-24 G. Torrealba , S. E. Koposov , V. Belokurov , M. Irwin , M. Collins , M. Spencer , R. Ibata , M. Mateo , A. Bonaca , P. Jethwa

The evidence of the phenomenon for which, in galaxies, the gravitating mass is distributed differently than the luminous mass, increases as new data become available. Furthermore, this discrepancy is well structured and it depends on the…

Astrophysics of Galaxies · Physics 2019-03-11 Paolo Salucci

An accurate knowledge of the dark matter distribution in the Milky Way is of crucial importance for galaxy formation studies and current searches for particle dark matter. In this paper we set new dynamical constraints on the Galactic dark…

Astrophysics of Galaxies · Physics 2015-12-03 Miguel Pato , Fabio Iocco , Gianfranco Bertone

We identify a large sample of isolated bright galaxies and their fainter satellites in the 2dF Galaxy Redshift Survey (2dFGRS). We analyse the dynamics of ensembles of these galaxies selected according to luminosity and morphological type…

Astrophysics · Physics 2009-11-13 Peder Norberg , Carlos S. Frenk , Shaun Cole

The detection of stars in the process of being tidally removed from globular clusters and dwarf spheroidals in the Galaxy's halo provides a strong constraint on their mass to light ratios and on the extent of their possible dark matter…

Astrophysics · Physics 2009-10-28 Ben Moore

A dynamical characterization of dark matter dominated dwarf galaxies from their observed effects on galactic disks (i.e. Galactoseismology) has remained an elusive goal. Here, we present preliminary results from spectroscopic observations…

The radial distribution of mass in a disk galaxy is strongly constrained by its rotation curve. The separate contributions from the individual stellar populations and dark matter (DM) are not easily disentangled, however, especially since…

Astrophysics · Physics 2007-05-23 J A Sellwood

We use observational properties of galaxies accumulated in the Updated Nearby Galaxy Catalog to derive a dark matter mass of luminous galaxies via motions of their companions. The data on orbital-to-stellar mass ratio are presented for 15…

Astrophysics of Galaxies · Physics 2015-06-19 Igor D. Karachentsev , Yuri N. Kudrya

This article reports a measurement of the proper motion of Leo II, a dwarf galaxy that is a likely satellite of the Milky Way, based on imaging with the Hubble Space Telescope and Wide Field Camera 3. The measurement uses compact background…

Astrophysics of Galaxies · Physics 2016-11-23 Slawomir Piatek , Carlton Pryor , Edward W. Olszewski