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Related papers: The Draco and Ursa Minor dwarf spheroidals. A comp…

200 papers

We analyze velocity dispersion profiles for the Draco and Ursa Minor (UMi) dwarf spheroidal (dSph) galaxies based on published and new Keck HIRES spectra for stars in the outer UMi field. Washington+DDO51 filter photometric catalogs provide…

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 discover an extended distribution of main-sequence (MS) stars along the minor axis of the Ursa Minor (UMi) dwarf spheroidal galaxy (dSph). This study is enabled by deep, wide Subaru/Hyper Suprime-Cam data, reaching photometric…

The nearby Ursa Minor dwarf spheroidal (UMi dSph) is one of the most dark matter dominated galaxies known, with a central mass to light ratio roughly equal to 70. Somewhat anomalously, it appears to contain morphological substructure in the…

Astrophysics · Physics 2009-11-07 Jan T. Kleyna , Mark I. Wilkinson , Gerard Gilmore , N. Wyn Evans

The recently discovered Ursa Major dwarf spheroidal (dSph) galaxy candidate is about five to eight times less luminous than the faintest previously known dSphs And IX, Draco, and UMi. In this Letter, we present velocity measurements of…

Astrophysics · Physics 2009-11-13 J. T. Kleyna , M. I. Wilkinson , N. W. Evans , G. Gilmore

Stellar candidates in the Ursa Minor (UMi) dwarf galaxy have been found using a new Bayesian algorithm applied to \textit{Gaia} EDR3 data. Five of these targets are located in the extreme outskirts of UMi, from $\sim5$ to 12 elliptical…

Dwarf satellite galaxies undergo strong tidal forces produced by the main galaxy potential. These forces disturb the satellite, producing asymmetries in its stellar distribution, tidal tail formation, and modifications of the velocity…

Astrophysics · Physics 2009-11-07 M. A. Gomez-Flechoso , D. Martinez-Delgado

We derive the star formation history (SFH) and chemical evolution history (CEH) of the Ursa Minor (UMi) dwarf spheroidal galaxy (dSph). We detect two distinct stellar populations that exist over 6 times half-light radius from its center.…

A simple and natural explanation for the dynamics and morphology of the Local Group Dwarf Spheroidal galaxies, Draco (Dra) and Ursa Minor (UMi), is that they are weakly unbound stellar systems with no significant dark matter component. A…

Astrophysics · Physics 2007-05-23 J. R. Kuhn , D. Kocevski , J. -J. Fleck

Results are presented of a deep optical survey of the Ursa Major Cluster, a spiral-rich cluster of galaxies at a distance of 18.6 Mpc which contains about 30% of the light but only 5% of the mass of the nearby Virgo Cluster. Fields around…

Astrophysics · Physics 2009-11-06 Neil Trentham , R. Brent Tully , Marc A. W. Verheijen

We use a large set of radial velocities in the Ursa Minor and Draco dwarf spheroidal galaxies to search for binary stars and to infer the binary frequency. Of the 118 stars in our sample with multiple observations, six are velocity…

Astrophysics · Physics 2009-10-28 E. Olszewski , C. Pryor , T. Armandroff

We model three dSph galaxies, Draco, Ursa Minor and Fornax, as axisymmetric stellar systems embedded in spherical dark-matter potentials, which are in dynamical equilibrium without significant external tidal forces. We construct…

Astrophysics · Physics 2007-05-23 Xiaoan Wu , submitted to ApJ

We present the results of the analysis of deep archival \sat\ observations towards the dwarf spheroidal galaxies Draco, Leo I, Ursa Major II and Ursa Minor in the Milky Way neighbourhood. The X-ray source population is characterized and…

Astrophysics of Galaxies · Physics 2015-09-09 L. Manni , A. A. Nucita , F. De Paolis , V. Testa , G. Ingrosso

We present deep and wide V, I CCD photometry of Ursa Major I (UMa I) dwarf spheroidal galaxy (dSph) in Local Group. The images of the galaxy were taken by Subaru/Suprime-Cam wide field camera, covering a field of 34\arcmin $\times$…

Astrophysics · Physics 2009-11-13 Sakurako Okamoto , Nobuo Arimoto , Yoshihiko Yamada , Masato Onodera

We present a large area photometric survey of the Ursa Minor dSph. We identify UMi giant star candidates extending to ~3 deg from the center of the dSph. Comparison to previous catalogues of stars within the tidal radius of UMi suggests…

Astrophysics · Physics 2010-11-09 C. Palma , S. Majewski , M. Siegel , R. Patterson , J. Ostheimer , R. Link

We present interpretations of the line-of-sight velocity distribution of stars in the Draco dwarf spheroidal galaxy in terms of CDM and MOND assuming constant mass-to-light ratio and anisotropy. We estimate the two parameters by fitting the…

Astrophysics · Physics 2009-11-13 Ewa L. Lokas , Gary A. Mamon , Francisco Prada

We explore the possible signatures of dark matter (DM) pair annihilations in the nearby dwarf spheroidal galaxy Draco. After investigating the mass models for Draco in the light of available observational data, we carefully model the DM…

Astrophysics · Physics 2008-11-26 S. Colafrancesco , S. Profumo , P. Ullio

Most dwarf spheroidal (dSph) satellites of the Milky Way follow exponential surface density profiles that decline sharply in the outer regions. The Sculptor (Scl) and Ursa Minor (UMi) dSphs deviate from this trend and show a clear excess of…

Astrophysics of Galaxies · Physics 2026-04-29 Daniel A. Boyea , Julio F. Navarro , Jaclyn Jensen , Raphaël Errani

Measuring the frequency of binary stars in dwarf spheroidal galaxies (dSphs) requires data taken over long time intervals. We combine radial velocity measurements from five literature sources taken over the course of ~30 years to yield the…

Astrophysics of Galaxies · Physics 2018-11-19 Meghin Spencer , Mario Mateo , Edward Olszewski , Matthew Walker , Alan McConnachie , Evan Kirby
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