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Related papers: Complexity in small-scale dwarf spheroidal galaxie…

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In the last decade, we have been able to probe further down the galaxy luminosity function than ever before and expand into the regime of ultra-faint dwarfs (UFDs), which are some of the best probes we have of small-scale cosmology and…

At present, dwarf spheroidal galaxies satellites of the Milky Way may represent the best astrophysical objects for dark matter (DM) searches with gamma-ray telescopes. They present the highest mass-to-light ratios known in the Universe.…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-13 Miguel A. Sanchez-Conde

We compare the dark matter halos' structural parameters derived for four Milky Way dwarf spheroidal galaxies to those of subhalos found in cosmological $N$-body simulations. We confirm that estimates of the mass at a single fixed radius are…

Astrophysics of Galaxies · Physics 2015-12-02 Maarten A. Breddels , Carlos Vera-Ciro , Amina Helmi

We present a homogeneous set of accurate atmospheric parameters for a complete sample of very and extremely metal-poor stars in the dwarf spheroidal galaxies (dSphs) Sculptor, Ursa Minor, Sextans, Fornax, Bo\"otes I, Ursa Major II, and Leo…

Solar and Stellar Astrophysics · Physics 2017-08-30 L. Mashonkina , P. Jablonka , Yu. Pakhomov , T. Sitnova , P. North

Recent years have seen a series of large-scale photometric surveys with the aim of detecting substructure in nearby dwarf galaxies. Some of these objects display a varying distribution of each stellar population, reflecting their star…

Astrophysics · Physics 2009-11-10 Matthew Coleman

We compare chemical abundances of Local Group dwarf spheroidals, obtained from recent UVES/VLT observations, and of high redshift Damped Lyman alpha systems (DLAs), corrected for dust effects. We focus, in particular, on the abundance ratio…

Astrophysics · Physics 2007-05-23 G. Vladilo , L. Sbordone , P. Bonifacio

Galaxy surveys have shown that luminous galaxies are mainly distributed in large filaments and galaxy clusters. The remaining large volumes are virtually devoid of luminous galaxies. This is in concordance with the formation of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Matthias Hoeft , Stefan Gottloeber

We investigate the formation and evolution of dwarf galaxies in a high resolution, hydrodynamical cosmological simulation of a Milky Way sized halo and its environment. Our simulation includes gas cooling, star formation, supernova…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Till Sawala , Cecilia Scannapieco , Simon White

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

Recent results from numerical simulations and models of galaxy formation suggest that recently discovered ultra-faint compact stellar systems (UFCSs) in the halo of the Milky Way (MW) may be some of the smallest and faintest galaxies. If…

High Energy Astrophysical Phenomena · Physics 2024-12-13 A. Circiello , A. McDaniel , A. Drlica-Wagner , C. Karwin , M. Ajello , M. Di Mauro , M. Sánchez-Conde

Aim: We establish the mean metallicity from high-resolution spectroscopy for the recently found dwarf spheroidal galaxy Bootes I and test whether it is a common feature for ultra-faint dwarf spheroidal galaxies to show signs of…

Astrophysics of Galaxies · Physics 2009-12-08 S. Feltzing , K. Eriksson , J. Kleyna , M. I. Wilkinson

We present high-resolution spectroscopic measurements of the abundances of titanium (Ti), yttrium (Y) and lanthanum (La) for M giant candidates of the Sagittarius (Sgr) dwarf spheroidal (dSph) + tidal tail system pre-selected on the basis…

We present spectroscopic metallicities of individual stars in seven gas-rich dwarf irregular galaxies (dIrrs), and we show that dIrrs obey the same mass-metallicity relation as the dwarf spheroidal (dSph) satellites of both the Milky Way…

Astrophysics of Galaxies · Physics 2013-12-02 Evan N. Kirby , Judith G. Cohen , Puragra Guhathakurta , Lucy Cheng , James S. Bullock , Anna Gallazzi

Spectroscopic studies of low-luminosity early-type galaxies are essential to understand their origin and evolution but remain challenging because of low surface brightness levels. We describe an observational campaign with the new…

Astrophysics of Galaxies · Physics 2019-10-11 Igor V. Chilingarian , Kirill A. Grishin , Anton V. Afanasiev , Daniel Fabricant , Sean Moran

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 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

The most metal-poor stars in the Milky Way witnessed the early phases of formation of the Galaxy, and have chemical compositions that are close to the pristine mixture from Big Bang nucleosynthesis, polluted by one or few supernovae. Only…

Deep, wide-area photometric surveys have uncovered a population of compact ($r_{1/2} \approx$ 1-15 pc), extremely-low-mass ($M_* \approx$ 20-4000 $M_{\odot}$) stellar systems in the Milky Way halo that are smaller in size than known…

We study the mass spectrum of destroyed dwarfs that contribute to the accreted stellar mass of Milky Way (MW) mass M_vir ~ 10^12.1 M_sun) halos using a suite of 45 zoom-in, dissipationless simulations. Empirical models are employed to…

Astrophysics of Galaxies · Physics 2016-04-20 Alis J. Deason , Yao-Yuan Mao , Risa H. Wechsler

The growing number of Milky Way satellites detected in recent years has introduced a new focus for stellar abundance analysis. Abundances of stars in satellites have been used to probe the nature of these systems and their chemical…