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Related papers: On Kinematic Substructure in the Sextans Dwarf Sph…

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A large extension of the Sextans dwarf spheroidal galaxy, 7 sq degrees, has been surveyed for variable stars using the Dark Energy Camera at the Blanco Telescope in Cerro Tololo Inter-American Observatory, Chile. We report 7 Anomalous…

Solar and Stellar Astrophysics · Physics 2019-03-06 Kathy Vivas , Javier Alonso-García , Mario Mateo , Alistair Walker , Brittany Howard

We model the large kinematic data sets for the four Milky Way dwarf spheroidal (dSph) satellites: Carina, Fornax, Sculptor and Sextans, recently published by Walker et al. The member stars are selected using a reliable dynamical interloper…

Astrophysics of Galaxies · Physics 2009-11-13 Ewa L. Lokas

Gaia DR2 has delivered full-sky 6-D measurements for millions of stars, and the quest to understand the dynamics of our Galaxy has entered a new phase. Our aim is to reveal and characterize the kinematic sub-structure of the different…

Astrophysics of Galaxies · Physics 2018-11-14 P. Ramos , T. Antoja , F. Figueras

We present stellar parameters and chemical abundances of 30 elements for five stars located at large radii (3.5-10.7 times the half-light radius) in the Sextans dwarf spheroidal galaxy. We selected these stars using proper motions, radial…

We present a spectroscopic survey of the newly-discovered Canes Venatici dwarf galaxy using the Keck/DEIMOS spectrograph. Two stellar populations of distinct kinematics are found to be present in this galaxy: an extended, metal-poor…

Astrophysics · Physics 2009-11-11 Rodrigo Ibata , Scott Chapman , Mike Irwin , Geraint Lewis , Nicolas Martin

We present the chemodynamic structure of the solar neighbourhood using 62 814 stars within a 500 pc sphere of the Sun observed by GALAH and with astrometric parameters from Gaia DR2. We measure the velocity dispersion for all three…

We present tentative evidence for the existence of a dissolved star cluster in the Sextans dwarf spheroidal galaxy. In a sample of six stars, we identify three (possibly four) stars around [Fe/H] =-2.7 that are highly clustered in a…

Cosmology and Nongalactic Astrophysics · Physics 2012-02-20 Torgny Karlsson , Joss Bland-Hawthorn

I review observational data on the kinematic properties of dwarf spheroidal galaxies in the halo of the Milky Way and beyond. The present data confirm previous claims that these galaxies have unusually large central velocity dispersions.…

Astrophysics · Physics 2007-05-23 Mario Mateo

We present metallicity and radial velocity for 450 bonafide members of the Sagittarius dwarf spheroidal (Sgr dSph) galaxy, measured from high resolution (R~18000) FLAMES@VLT spectra. The targets were carefully selected (a) to sample the…

We present a 2D kinematic analysis out to ~2-5 effective radii (Re) of 33 massive elliptical galaxies with stellar velocity dispersions larger than 150 km/s. Our observations were taken using the Mitchell Spectrograph (formerly VIRUS-P), a…

Astrophysics of Galaxies · Physics 2015-06-19 Sudhir Raskutti , Jenny Greene , Jeremy Murphy

Here we present a kinematic study of the Galactic halo out to a radius of $\sim$ 60 kpc, using 4664 blue horizontal branch (BHB) stars selected from the SDSS/SEGUE survey, to determine key dynamical properties. Using a maximum likelihood…

Astrophysics of Galaxies · Physics 2012-12-04 Prajwal R. Kafle , Sanjib Sharma , Geraint F. Lewis , Joss Bland-Hawthorn

Using Gaia DR3 data, we examine the kinematics of the central core of the Sagittarius (Sgr) dwarf spheroidal galaxy using data which includes proper motions and line-of-sight velocities for member stars in addition to their projected…

Astrophysics of Galaxies · Physics 2025-08-28 Isabelle S. Goldstein , Louis E. Strigari

In order to minimize environmental effects and gain an insight into the internal mechanisms that shape the properties of the early-type dwarf systems, we study one of the few isolated dwarf spheroidal galaxies (dSphs) of the Local Group…

Astrophysics of Galaxies · Physics 2018-10-31 S. Taibi , G. Battaglia , N. Kacharov , M. Rejkuba , M. Irwin , R. Leaman , M. Zoccali , E. Tolstoy , P. Jablonka

We present projected velocity dispersion profiles for the Draco and Ursa Minor (UMi) dwarf spheroidal galaxies based on 207 and 162 discrete stellar velocities, respectively. Both profiles show a sharp decline in the velocity dispersion…

Astrophysics · Physics 2009-11-10 M. I. Wilkinson , J. T. Kleyna , N. W. Evans , G. F. Gilmore , M. J. Irwin , E. K. Grebel

We present the high-resolution spectroscopic analysis of two new extremely metal-poor stars (EMPS) candidates in the dwarf spheroidal galaxy Sextans. These targets were pre-selected from medium resolution spectra centered around the Ca II…

Astrophysics of Galaxies · Physics 2021-01-04 R. Lucchesi , C. Lardo , F. Primas , P. Jablonka , P. North , G. Battaglia , E. Starkenburg , V. Hill , M. Irwin , P. Francois , M. Shetrone , E. Tolstoy , K. Venn

Dwarf spheroidal galaxies (dSphs) have been extensively investigated in the Local Group, but their low luminosity and surface brightness make similar work in more distant galaxy groups challenging. Modern instrumentation unlocks the…

We construct a new sample of ~1700 solar neighbourhood halo subdwarfs from the Sloan Digital Sky Survey, selected using a reduced proper motion diagram. Radial velocities come from the SDSS spectra and proper motions from the light-motion…

Astrophysics of Galaxies · Physics 2009-11-19 M. C. Smith , N. W. Evans , V. Belokurov , P. C. Hewett , D. M. Bramich , G. Gilmore , M. J. Irwin , S. Vidrih , D. B. Zucker

We investigate the spatial distribution, kinematics, and metallicity of stars in the Draco dwarf spheroidal galaxy using data from the Dark Energy Spectroscopic Instrument (DESI). We identify 155 high probability members of Draco using line…

We present a homogeneous kinematic analysis of red giant branch stars within 18 of the 28 Andromeda dwarf spheroidal (dSph) galaxies, obtained using the Keck I LRIS and Keck II DEIMOS spectrographs. Based on their g-i colors (taken with the…

The High Resolution Echelle Spectrometer on the Keck I telescope has been used to measure nine radial velocities having a median precision of 2 km/s for seven red giants belonging to the isolated dwarf spheroidal galaxy Andromeda II. We…

Astrophysics · Physics 2009-10-31 Patrick Cote , Mario Mateo , Edward Olszewski , Kem Cook