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Related papers: Mapping the Galactic Halo VIII: Quantifying substr…

200 papers

We have detected over 400 HI clouds in the lower halo of the Galaxy within the pilot region of the Galactic All-Sky Survey (GASS), a region of the fourth quadrant that spans 18 degrees in longitude, 40 degrees in latitude and is centered on…

In numerous studies of the outer Galactic halo some evidence for accretion has been found. If the outer halo did form in part or wholly through merger events, we might expect to find coherent streams of stars and globular clusters following…

Astrophysics · Physics 2009-11-07 Christopher Palma , Steven R. Majewski , Kathryn V. Johnston

Over the next decade, the astronomical community will be commissioning multiple wide-field observatories well-suited for studying stellar halos in both integrated light and resolved stars. In preparation for this, we use five…

The Milky Way halo is one of the few galactic haloes that provides a unique insight into galaxy formation by resolved stellar populations. Here, we present a catalogue of $\sim$47 million halo stars selected independent of parallax and…

We develop a semi-analytic method for determining the phase-space population of tidal debris along the orbit of a disrupting satellite galaxy and illustrate its use with a number of applications. We use this method to analyze Zhao's…

Astrophysics · Physics 2010-04-06 Kathryn V. Johnston

We select satellite galaxies from the galaxy group catalog constructed with the SDSS spectroscopic galaxies and measure the tangential shear around these galaxies with source catalog extracted from CFHT/MegaCam Stripe-82 Survey to constrain…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-03 Ran Li , Huanyuan Shan , HouJun Mo , Jean-Paul Kneib , Xiaohu Yang , Wentao Luo , Frank C. van den Bosch , Thomas Erben , Bruno Moraes , Martin Makler

Stellar halos are the only major stellar component of disk galaxies that lack systematic observational characterization, yet they encode critical information about galaxy merger histories. We present the first systematic census of stellar…

Astrophysics of Galaxies · Physics 2026-02-25 Bojun Tao , Hong-Xin Zhang , Wenting Wang , Enci Wang , Guangwen Chen , Huiyuan Wang , Lijun Chen , Qian-Hui Chen , Song Huang , Xu Kong , Yu Rong

Using the data from the Sloan Digital Sky Survey and the Gaia satellite, we assemble a pure sample of $\sim$3000 Blue Horizontal Branch (BHB) stars with 7-D information, including positions, velocities and metallicities. We demonstrate…

Astrophysics of Galaxies · Physics 2020-02-18 Lachlan Lancaster , Sergey E. Koposov , Vasily Belokurov , N. Wyn Evans , Alis J. Deason

We have identified over 2000 well resolved cluster halos, and also their associated bound subhalos, from the output of a 1024^3 particle cosmological N-body simulation (of box size 320 h^-1 Mpc and softening length 3.2 h^-1 kpc). This has…

Astrophysics · Physics 2010-11-11 L. D. Shaw , J. Weller , J. P. Ostriker , P. Bode

We discuss the density and radial velocity distributions of over 3000 candidate RR Lyrae stars selected by various methods using Sloan Digital Sky Survey data for about 1000 deg^2 of sky. This is more than 20 times larger sample than…

We have performed the largest ever particle simulation of a Milky Way-sized dark matter halo, and present the most comprehensive convergence study for an individual dark matter halo carried out thus far. We have also simulated a sample of 6…

AIMS. We derive the morphology of the stellar component in the outer halo volume, and search for possible overdensities due to substructures therein. METHODS. We made use of some of the data releases of the spectroscopic survey LAMOST…

Astrophysics of Galaxies · Physics 2024-02-09 M. Lopez-Corredoira , X. -C. Tang , H. Tian , H. -F. Wang , G. Carraro , C. Liu

An all high-latitude sky survey for cool carbon giant stars in the Galactic halo has revealed 75 such stars, of which the majority are new detections. Of these, more than half are clustered on a Great Circle on the sky which intersects the…

Astrophysics · Physics 2009-10-31 Rodrigo Ibata , Geraint F. Lewis , Michael Irwin , Edward Totten , Thomas Quinn

As part of our survey for substructure in the Milky Way halo as traced by giant stars, and to look for tidal stellar debris in the halo viable for measurement of the Galactic mass potential with SIM, we explore the distribution of stars…

We study the dynamical properties of halo stars located in the Solar Neighbourhood. Our goal is to explore how the properties of the halo depend on the selection criteria used for defining a sample of halo stars. Once this is understood we…

Astrophysics of Galaxies · Physics 2018-07-18 Lorenzo Posti , Amina Helmi , Jovan Veljanoski , Maarten Breddels

Precise proper motion measurements (sigma_mu ~ 10 mkas/yr) of the recently discovered hyper-velocity star (HVS) SDSS J090745.0+024507 would yield significant constraints on the axis ratios and orientation of a triaxial model for the…

Astrophysics · Physics 2009-11-13 Oleg Y. Gnedin , Andrew Gould , Jordi Miralda-Escude , Andrew R. Zentner

Samples of reliably identified halo wide binaries are scarce. If reasonably free from selection effects and with a small degree of contamination by chance alignments, these wide binaries become a powerful dynamical tool, having provided one…

Solar and Stellar Astrophysics · Physics 2018-08-20 Johanna Coronado , María Paz Sepúlveda , Andrew Gould , Julio Chanamé

According to the current cosmological cold dark matter paradigm, the Galactic halo could have been the result of the assemblage of smaller structures. Here we explore the hypothesis that the classical and ultra-faint dwarf spheroidal…

Astrophysics of Galaxies · Physics 2016-03-23 E. Spitoni , F. Vincenzo , F. Matteucci , D. Romano

We present the discovery of three new Milky Way satellites from our search for compact stellar overdensities in the photometric catalog of the Panoramic Survey Telescope and Rapid Response System 1 (Pan-STARRS 1, or PS1) 3pi survey. The…

Can N-body simulations reliably determine the structural properties of dark matter halos? Focussing on a Virgo-sized galaxy cluster, we increase the resolution of current ``high resolution simulations'' by almost an order of magnitude to…

Astrophysics · Physics 2008-11-26 Sebastiano Ghigna , Ben Moore , Fabio Governato , George Lake , Tom Quinn , Joachim Stadel