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Related papers: What is Missing from the Local Stellar Halo?

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[Abridged] Motivated by upcoming data from astrometric and spectroscopic surveys of the Galaxy, we explore the chemical abundance properties and phase-space distributions in hierarchically-formed stellar halo simulations set in a LambdaCDM…

Astrophysics · Physics 2008-11-26 Andreea S. Font , Kathryn V. Johnston , James S. Bullock , Brant E. Robertson

We use data from the IAC Stripe82 Legacy Project to study the surface photometry of 22 nearby, face-on to moderately inclined spiral galaxies. The reprocessed and combined Stripe 82 $g'$, $r'$ and $i'$ images allow us to probe the galaxy…

Astrophysics of Galaxies · Physics 2017-06-28 S. P. C. Peters , P. C. van der Kruit , J. H. Knapen , I. Trujillo , J. Fliri , M. Cisternas , L. S. Kelvin

In a framework where galaxies form hierarchically, extended stellar haloes are predicted to be an ubiquitous feature around Milky Way-like galaxies and to consist mainly of the shredded stellar component of smaller galactic systems. The…

Astrophysics of Galaxies · Physics 2017-12-20 G. Battaglia , P. North , P. Jablonka , M. Shetrone , D. Minniti , M. Díaz , E. Starkenburg , M. Savoy

We investigate the build-up of the accreted stellar and dark matter haloes of Milky Way-like galaxies in APOSTLE suite of cosmological hydrodynamics simulations. We show that the stellar halo is made up primarily of stars stripped from a…

Astrophysics of Galaxies · Physics 2023-02-15 Anna Genina , Alis Deason , Carlos Frenk

We have learned recently that the inner halo of the Milky Way contains a kinematically coherent component (Gaia-Enceladus) from a significant merger 10 Gyrs ago. By contrast the inner halo (defined to exclude the Magellanic Stream) contains…

Astrophysics of Galaxies · Physics 2019-03-20 Jeremy Mould

Deep photometric surveys of the Milky Way have revealed diffuse structures encircling our Galaxy far beyond the "classical" limits of the stellar disk. This paper reviews results from our own and other observational programs, which together…

We analyze the observed spatial, chemical and dynamical distributions of local metal-poor stars, based on photometrically derived metallicity and distance estimates along with proper motions from the Gaia mission. Along the Galactic prime…

Astrophysics of Galaxies · Physics 2021-09-29 Deokkeun An , Timothy C. Beers

We present an analysis of the radial age gradients for the stellar halos of five Milky Way mass-sized systems simulated as part of the Aquarius Project. The halos show a diversity of age trends, reflecting their different assembly…

We measure for the first time the outermost edges of the Milky Way (MW) halo in terms of the depletion and turnaround radii. The inner depletion radius, $r_\mathrm{id}$, identified at the location of maximum infall velocity, separates a…

Astrophysics of Galaxies · Physics 2021-07-06 Zhao-Zhou Li , Jiaxin Han

We investigate the structure of the Milky Way's stellar halo within 70 kpc of the Sun using a wide-field photometric catalog obtained from the Hyper Suprime-Cam (HSC) Subaru Strategic Program (HSC-SSP). We employ a large sample of…

Astrophysics of Galaxies · Physics 2026-04-14 Yoshihisa Suzuki , Masashi Chiba , Rosemary F. G. Wyse , Shunichi Horigome

A wealth of recent studies have shown that the LMC is likely massive, with a halo mass $>10^{11} M_\odot$. One consequence of having such a nearby and massive neighbour is that the inner Milky Way is expected to be accelerated with respect…

The wealth of data in the past decades, and especially in the past 15 years has transformed our picture of the gas around the Milky Way and other spiral galaxies. There is good evidence for extraplanar gas that is a few kpc in height and is…

Cosmology and Nongalactic Astrophysics · Physics 2009-07-22 Joel N. Bregman

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…

The last 10-20 years has seen a profound shift in views of how the Galaxy's halo formed. The idea of a monolithic early collapse of a single system (Eggen, Lynden-Bell and Sandage 1962) has been challenged by observations at high redshift…

Taking advantage of the ultra-deep near-infrared imaging obtained with the Hubble Space Telescope on the Hubble Ultra Deep Field, we detect and explore for the first time the properties of the stellar haloes of two Milky Way-like galaxies…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Ignacio Trujillo , Judit Bakos

Theoretical and observational arguments suggest that there is a large amount of hot ($\sim 10^6$ K), diffuse gas residing in the Milky Way's halo, while its total mass and spatial distribution are still unclear. In this work, we present a…

Astrophysics of Galaxies · Physics 2020-05-06 Xiang-Er Fang , Fulai Guo , Ye-Fei Yuan

We present the study of a set of N-body+SPH simulations of a Milky Way-like system produced by the radiative cooling of hot gas embedded in a dark matter halo. The galaxy and its gaseous halo evolve for 10 Gyr in isolation, which allows us…

The halo stars on highly radial orbits should inevitably pass the center regions of the Milky Way. Under the assumption that the stellar halo is in dynamical equilibrium and axisymmetric, we integrate the orbits of $\sim 10,000$ halo…

Astrophysics of Galaxies · Physics 2022-11-16 Chengqun Yang , Ling Zhu , Behzad Tahmasebzadeh , Xiang-Xiang Xue , Chao Liu

The assembly process of our Galaxy can be retrieved using the motions and chemistry of individual stars. Chemo-dynamical studies of the nearby halo have long hinted at the presence of multiple components such as streams, clumps, duality and…

Astrophysics of Galaxies · Physics 2018-11-14 Amina Helmi , Carine Babusiaux , Helmer H. Koppelman , Davide Massari , Jovan Veljanoski , Anthony G. A. Brown

Recent observational and theoretical work suggests that the formation of the Galactic stellar halo involved both dissipative processes and the accretion of subfragments. With present data, the fraction of the halo for which an accretion…

Astrophysics · Physics 2007-05-23 Ortwin Gerhard