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Related papers: Trimming Down the Willman 1 dSph

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The ultra-faint Milky Way satellite Willman 1 (W1; $M_V = -2.6$; $r_{\rm half} \sim27$ pc) was the first stellar over-density found via resolved stars in the Sloan Digital Sky Survey, yet its classification as either a dwarf galaxy or star…

We investigate the kinematic properties and stellar population of the Galactic satellite Willman 1 (Wil 1) by combining Keck/DEIMOS spectroscopy with KPNO mosaic camera imaging. Wil 1 is an ultra-low luminosity Milky Way companion. This…

Astrophysics of Galaxies · Physics 2015-05-19 Beth Willman , Marla Geha , Jay Strader , Louis E. Strigari , Joshua D. Simon , Evan Kirby , Alex Warres

SDSSJ1049+5103, commonly known as Willman 1, is an extremely low-luminosity Milky Way companion whose properties are intermediate between those of globular clusters and dwarf spheroidals. In this paper, we use deep photometry to show that…

An initial assessment is made of white dwarf and hot subdwarf stars observed in the Sloan Digital Sky Survey. In a small area of sky (190 square degrees), observed much like the full survey will be, 269 white dwarfs and 56 hot subdwarfs are…

Observational bias against finding Milky Way (MW) dwarf galaxies at low Galactic latitudes (b < 20 deg) and at low surface brightnesses (fainter than 29 mag arcsec^-2, in the V-band) currently limits our understanding of the faintest limits…

Astrophysics of Galaxies · Physics 2015-11-11 Mariah Baker , Beth Willman

Almost every known low-luminosity Milky Way dwarf spheroidal (dSph) satellite galaxy contains at least one RR Lyrae star. Assuming that a fraction of distant (60 < d_{helio} < 100 kpc) Galactic halo RR Lyrae stars are members of yet to be…

{Abridged} We report the discovery of six compact, starburst galaxy candidates with redshifts 2.3 < z < 2.8 and r-band magnitudes 19.8-20.5 in the Quasar Catalog of the Sloan Digital Sky Survey First Data Release (SDSS DR1). The SDSS…

Astrophysics · Physics 2009-11-10 Misty C. Bentz , Patrick S. Osmer , David H. Weinberg

White dwarfs are among the most common objects in the stellar halo; however, due to their low luminosity and low number density compared to the stars in the discs of the Milky Way, they are scarce in the observable volume. Hence, they are…

Astrophysics of Galaxies · Physics 2017-02-09 Marco C. Lam

We present new metallicity measurements for 298 individual red giant branch stars in eight of the least luminous dwarf spheroidal galaxies (dSphs) in the Milky Way (MW) system. Our technique is based on medium resolution Keck/DEIMOS…

Astrophysics · Physics 2010-10-28 Evan N. Kirby , Joshua D. Simon , Marla Geha , Puragra Guhathakurta , Anna Frebel

Recently, Carraro (2005) drew attention to the remarkable star cluster Whiting 1 by showing that it lies about 40 kpc from the Sun and is therefore unquestionably a member of the Galactic halo (b=-60.6 deg.). Its CMD indicated that Whiting…

Astrophysics · Physics 2009-11-13 Giovanni Carraro , Robert Zinn , Christian Moni Bidin

Whiting 1 is a member of the fast-growing group of young globular clusters in the Milky Way halo. Preliminary estimates of its fundamental parameters have been provided using optical photometry and low resolution spectroscopy. In an attempt…

Solar and Stellar Astrophysics · Physics 2015-06-23 A. T. Valcheva , E. P. Ovcharov , A. D. Lalova , P. L. Nedialkov , V. D. Ivanov , G. Carraro

We predict that there is a population of low-luminosity dwarf galaxies orbiting within the halo of the Milky Way that have surface brightnesses low enough to have escaped detection in star-count surveys. The overall count of stealth…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 James S. Bullock , Kyle R. Stewart , Manoj Kaplinghat , Erik J. Tollerud , Joe Wolf

We present the full spectroscopic white dwarf and hot subdwarf sample from the SDSS first data release, DR1. We find 2551 white dwarf stars of various types, 240 hot subdwarf stars, and an additional 144 objects we have identified as…

We present Washington photometry of a field central to the Bootes I dwarf spheroidal galaxy, which was discovered as a stellar overdensity in the Sloan Digital Sky Survey (DR5). We show that the Washington filters are much more effective…

Astrophysics · Physics 2009-11-13 Joanne Hughes , George Wallerstein , Anne Bossi

We examine the prospects for detecting gamma-rays from dark matter annihilation in the six most promising dwarf spheroidal (dSph) satellite galaxies of the Milky Way. We use recently-measured velocity dispersion profiles to provide a…

We use kinematic data from three new, nearby, extremely low-luminosity Milky Way dwarf galaxies (Ursa Major II, Willman 1, and Coma Berenices) to constrain the properties of their dark matter halos, and from these make predictions for the…

A new set of very high signal-to-noise (S/N > 100/1), medium-resolution (R~3000) optical spectra have been obtained for 302 of the candidate "weak-metal" stars selected by Bidelman & MacConnell. We use these data to calibrate the recently…

We have conducted a survey of 61 southern white dwarfs searching for magnetic fields using Zeeman spectropolarimetry. Our objective is to obtain a magnetic field distribution for these objects and, in particular, to find white dwarfs with…

Astrophysics · Physics 2008-11-26 A. Kawka , S. Vennes , G. D. Schmidt , D. T. Wickramasinghe , R. Koch

In this Letter, we report the discovery of a new dwarf satellite to the Milky Way, located at ($\alpha_{2000}, \delta_{2000}$) $=$ (158.72,51.92) in the constellation of Ursa Major. This object was detected as an overdensity of red,…

The lowest luminosity (L < 10^5 L_sun) Milky Way satellite galaxies represent the extreme lower limit of the galaxy luminosity function. These ultra-faint dwarfs are the oldest, most dark matter-dominated, most metal-poor, and least…

Astrophysics of Galaxies · Physics 2019-09-11 Joshua D. Simon
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