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Related papers: Stellar velocity distributions in binary-rich ultr…

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Over the past five years, searches in Sloan Digital Sky Survey data have more than doubled the number of known dwarf satellite galaxies of the Milky Way, and have revealed a population of ultra-faint galaxies with luminosities smaller than…

Cosmology and Nongalactic Astrophysics · Physics 2009-02-23 James S. Bullock , Manoj Kaplinghat , Andrew Fruchter , Marla Geha , Joshua D. Simon , Louis E. Strigari , Beth Willman

By means of interferometic 21-cm observations and a 3D kinematic modeling technique, we study the gas kinematics of six HI-rich ultra-diffuse galaxies (UDGs). We derive robust circular velocities and baryonic masses, that allow us to study…

Astrophysics of Galaxies · Physics 2019-10-17 Pavel E. Mancera Piña , Filippo Fraternali , Elizabeth A. K. Adams , Tom Oosterloo

We present the results of a weak gravitational lensing analysis to determine whether the stellar mass or the velocity dispersion is more closely related to the amplitude of the lensing signal around galaxies - and hence to the projected…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Edo van Uitert , Henk Hoekstra , Marijn Franx , David G. Gilbank , Michael D. Gladders , H. K. C. Yee

In this paper we explore the effects that the presence of a fraction of binary stars has in the determination of a star cluster mass via the virial theorem. To reach this aim in an accurate and consistent way, we run a set of simulations…

Solar and Stellar Astrophysics · Physics 2020-07-01 Sara Rastello , Giovanni Carraro , Roberto Capuzzo-Dolcetta

We demonstrate how the least luminous galaxies in the Universe, ultra-faint dwarf galaxies, are sensitive to their dynamical mass at the time of cosmic reionization. We select a low-mass ($\sim \text{1.5} \times 10^{9} \, \text{M}_{\odot}$)…

We address the effects of cosmological surface brightness dimming on observations of faint galaxies by examining the distribution of "unobscured" star formation rate intensities versus redshift. We use the star formation rate intensity…

In addition to their low stellar densities, ultra-diffuse galaxies (UDGs) have a broad variety of dynamical mass-to-light ratios, ranging from dark matter (DM) dominated systems to objects nearly devoid of DM. To investigate the origin of…

Astrophysics of Galaxies · Physics 2022-02-04 Sebastian Trujillo-Gomez , J. M. Diederik Kruijssen , Marta Reina-Campos

We use the observed abundances of ultra-diffuse galaxies (UDGs) in clusters and groups and \Lambda CDM subhalo mass functions to put constraints on the distribution {of present-day halo masses of satellite} UDGs. If all of the most massive…

Astrophysics of Galaxies · Physics 2018-02-07 Nicola C. Amorisco

We investigate the impact of binary orbital motions on the dynamical modeling of dwarf galaxies with intrinsic line-of-sight velocity dispersions ($\sigma_{v_r}$) of 1 to 9 km/s. Using dwarf galaxies from the Auriga level-2 and level-3…

Astrophysics of Galaxies · Physics 2023-08-30 Wenting Wang , Ling Zhu , Yipeng Jing , Robert J. J. Grand , Zhaozhou Li , Xiaoting Fu , Lu Li , Jiaxin Han , Ting S. Li , Fabo Feng , Carlos Frenk

The Leo T dwarf galaxy, the faintest and least massive galaxy known to have recent star formation ($\leq 1~Gyr$), exhibits a high dynamical mass-to-light ratio based on its stellar velocity dispersion ($7.07^{+1.29}_{-1.12}~\mathrm{km\…

Astrophysics of Galaxies · Physics 2026-03-04 Daniel Vaz , Jarle Brinchmann , Sebastian Kamann , Sara Saracino , P. A. C. Cunha , Mariana P. Júlio

We have analyzed the bivariate distribution of galaxies as a function of ultraviolet-optical colors and absolute magnitudes in the local universe. The sample consists of galaxies with redshifts and optical photometry from the Sloan Digital…

Elucidating dark matter density profiles in the Galactic dwarf satellites is essential to understanding not only the quintessence of dark matter, but also the evolution of the satellites themselves. In this work, we present the current…

Astrophysics of Galaxies · Physics 2023-06-30 Kohei Hayashi , Yutaka Hirai , Masashi Chiba , Tomoaki Ishiyama

The dark matter distribution in dwarf galaxies holds a wealth of information on the fundamental properties and interactions of the dark matter particle. In this paper, we study whether ultralight bosonic dark matter is consistent with the…

Astrophysics of Galaxies · Physics 2023-01-26 Isabelle S. Goldstein , Savvas M. Koushiappas , Matthew G. Walker

Assuming spherical symmetry and dynamical equilibrium within a given gravitational potential, a dwarf spheroidal (dSph) galaxy's globally averaged stellar velocity dispersion depends entirely on the shape of its stellar density profile.…

Astrophysics of Galaxies · Physics 2026-02-13 Sofia L. Splawska , Raphaël Errani , Jorge Peñarrubia , Matthew G. Walker

We use analytical and N-body methods to examine the survival of wide stellar binaries against repeated encounters with dark substructures orbiting in the dark matter haloes of dwarf spheroidal galaxies (dSphs). Our models adopt…

Astrophysics of Galaxies · Physics 2010-06-01 Jorge Penarrubia , Sergey E. Koposov , Matthew G. Walker , Gerry Gilmore , N. Wyn Evans , Craig D. Mackay

Low mass galaxies in the Local Group are dominated by dark matter and comprise the well studied ``dwarf Spheroidal" (dSph) class, with typical masses of $10^{9-10}M_\odot$ and also the equally numerous ``ultra faint dwarfs" (UFD),…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-20 Alvaro Pozo , Tom Broadhurst , George F. Smoot , Tzihong Chiueh , Hoang Nhan Luu , Mark Vogelsberger , Philip Mocz

Using collisionless N-body simulations of dwarf galaxies orbiting the Milky Way (MW) we construct realistic models of dwarf spheroidal (dSph) galaxies of the Local Group. The dwarfs are initially composed of stellar disks embedded in dark…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Klaudia Kowalczyk , Ewa L. Lokas , Stelios Kazantzidis , Lucio Mayer

Recent observations have revealed the existence of an abundant population of faint, low surface brightness (SB) galaxies, which appear to be numerous and ubiquitous in nearby galaxy clusters, including the Virgo, Coma and Fornax clusters.…

Astrophysics of Galaxies · Physics 2016-04-27 N. C. Amorisco , A. Loeb

We study the vertical stellar distribution of the Milky Way thin disk in detail with particular focus on the outer disk. We treat the galactic disk as a gravitationally coupled, three-component system consisting of stars, atomic hydrogen…

Astrophysics of Galaxies · Physics 2018-10-03 Suchira Sarkar , Chanda J Jog

Many young extra-galactic clusters have a measured velocity dispersion that is too high for the mass derived from their age and total luminosity, which has led to the suggestion that they are not in virial equilibrium. Most of these…

Solar and Stellar Astrophysics · Physics 2015-05-14 M. Gieles , H. Sana , S. F. Portegies Zwart