Substructure in the stellar halos of the Aquarius simulations

Abstract

We characterize substructure in the simulated stellar halos of Cooper et al. (2010) which were formed by the disruption of satellite galaxies within the cosmological N-body simulations of galactic halos of the Aquarius Project. These stellar halos exhibit a wealth of tidal features: broad overdensities and very narrow faint streams akin to those observed around the Milky Way. The substructures are distributed anisotropically on the sky, a characteristic that should become apparent in the next generation of photometric surveys. The normalized RMS of the density of stars on the sky appears to be systematically larger for our halos compared to the value estimated for the Milky Way from main sequence turn-off stars in the Sloan Digital Sky Survey. We show that this is likely to be due in part to contamination by faint QSOs and redder main sequence stars, and might suggest that ~10% of the Milky Way halo stars have formed in-situ.

5 pages, 5 color figures, accepted on April 8, 2011 with a change in title. A high-resolution version of the paper may be found at: http://www.astro.rug.nl/~ahelmi/aquarius.html

References in corpus (11)

• The accretion origin of the Milky Way's stellar halo
• The Dual Origin of Stellar Halos
• An Orphan in the "Field of Streams"
• The stellar halo of the Galaxy
• The Origin of the Bifurcation in the Sagittarius Stream
• The Galaxy and its stellar halo: insights on their formation from a hybrid cosmological approach
• The Causes of Halo Shape Changes Induced by Cooling Baryons: Disks Versus Substructures
• The Hercules-Aquila Cloud
• Infall of substructures onto a Milky Way-like dark halo
• The Overdensity in Virgo, Sagittarius Debris, and the Asymmetric Spheroid
• The Sphericalization of Dark Matter Halos by Galaxy Disks

Cited by in corpus (59)

• Overview of the DESI Legacy Imaging Surveys
• The Atlas3D project -- XXIX. The new look of early-type galaxies and surrounding fields disclosed by extremely deep optical images
• The large-scale structure of the halo of the Andromeda Galaxy Part I: global stellar density, morphology and metallicity properties
• Multiple retrograde substructures in the Galactic halo: A shattered view of Galactic history
• Project Overview of the Beijing-Arizona Sky Survey
• Structure Finding in Cosmological Simulations: The State of Affairs
• Global structure and kinematics of stellar haloes in cosmological hydrodynamic simulations
• Formation of In Situ Stellar Haloes in Milky Way-Mass Galaxies
• The origin of galactic metal-rich stellar halo components with highly eccentric orbits
• Diverse Stellar Haloes in Nearby Milky Way-Mass Disc Galaxies
• A box full of chocolates: The rich structure of the nearby stellar halo revealed by Gaia and RAVE
• Estimating the dark matter halo mass of our Milky Way using dynamical tracers
• Discovery of $\sim$ 9,000 new RR Lyrae in the Southern Catalina Surveys
• Stellar Streams and Clouds in the Galactic Halo
• Galactic Archaeology. The dwarfs that survived and perished
• Mapping substructure in the HST Frontier Fields cluster lenses and in cosmological simulations
• The PAndAS Field of Streams: stellar structures in the Milky Way halo toward Andromeda and Triangulum
• The first all-sky view of the Milky Way stellar halo with Gaia+2MASS RR Lyrae
• La Silla QUEST RR Lyrae Star Survey: Region I
• Kinematics and simulations of the stellar stream in the halo of the Umbrella Galaxy
• The information content of stellar halos: Stellar population gradients and accretion histories in early-type Illustris galaxies
• Action-space clustering of tidal streams to infer the Galactic potential
• Empirical Determination of Dark Matter Velocities using Metal-Poor Stars
• The Effects of Patchy Reionization on Satellite Galaxies of the Milky Way
• A panoramic VISTA of the stellar halo of NGC 253
• Discovery of a Stellar Overdensity in Eridanus-Phoenix in the Dark Energy Survey
• The aftermath of the Great Collision between our Galaxy and the Large Magellanic Cloud
• A comprehensive view of the Virgo Stellar Stream
• Modeling the gravitational potential of a cosmological dark matter halo with stellar streams
• Characterization of the VVV Survey RR Lyrae Population across the Southern Galactic Plane
• Streams Going Notts: The tidal debris finder comparison project
• Exploring Halo Substructure with Giant Stars. XV. Discovery of a Connection between the Monoceros Ring and the Triangulum-Andromeda Overdensity?
• Insight Into the Formation of the Milky Way Through Cold Halo Substructure. III. Statistical Chemical Tagging in the Smooth Halo
• The central spheroids of Milky Way mass-sized galaxies
• Exposing Sgr tidal debris behind the Galactic disk with M giants selected in WISE$\cap$2MASS
• Systematic Problems With Using Dark Matter Simulations to Model Stellar Halos
• To the Galactic Virial Radius with Hyper Suprime-Cam
• A Two-Point Correlation Function For Galactic Halo Stars
• The Unmixed Debris of Gaia-Sausage/Enceladus in the Form of a Pair of Halo Stellar Overdensities
• Quantifying the Smoothness of the Stellar Halo: A Link to Accretion History
• Disentangling the Virgo Overdensity with RR Lyrae stars
• New Signatures of the Milky Way Formation in the Local Halo and Inner Halo Streamers in the Era of Gaia
• What to expect from dynamical modelling of galactic haloes
• New views of the distant stellar halo
• Confronting Models of Dwarf Galaxy Quenching with Observations of the Local Group
• The halo of M105 and its group environment as traced by planetary nebula populations: I. Wide-field photometric survey of planetary nebulae in the Leo I group
• Predictions for the detection of Tidal Streams with Gaia using Great Circle Methods
• Comparing semi-analytic particle tagging and hydrodynamical simulations of the Milky Way's stellar halo
• Probing the Halo From the Solar Vicinity to the Outer Galaxy: Connecting Stars in Local Velocity Structures to Large-Scale Clouds
• The Next Generation Virgo Cluster Survey. XIX. Tomography of Milky Way Substructures in the NGVS Footprint
• Particle tagging and its implications for stellar population dynamics
• Leaves on trees: identifying halo stars with extreme gradient boosted trees
• Characterizing the SHARDS of Disrupted Milky Way Satellites with LAMOST
• Origins and Interpretation of Tidal Debris
• The kinematics of globular clusters systems in the outer halos of the Aquarius simulations
• The Chemodynamical Nature of the Triangulum-Andromeda Overdensity
• Tomography of stellar halos: what does anisotropy in a stellar halo tell us?
• Probing the spatial and velocity anisotropies in stellar halos from the Aquarius simulations
• Stellar orbital properties as diagnostics of the origin of the stellar halo