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Related papers: Binary star population of the Sculptor dwarf galax…

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We describe a search for close spectroscopic dwarf M star binaries using data from the Sloan Digital Sky Survey (SDSS) to address the question of the rate of occurrence of multiplicity in M dwarfs. We use a template fitting technique to…

Solar and Stellar Astrophysics · Physics 2015-05-30 Benjamin M. Clark , Cullen H. Blake , Gillian R. Knapp

We use time-resolved spectra from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) to examine the distribution of radial velocity (RV) variations in 249 stars identified as members of the Sagittarius (Sgr) dwarf…

Dwarf spheroidal galaxies (dSphs) appear to be some of the most dark matter dominated objects in the Universe. Their dynamical masses are commonly derived using the kinematics of stars under the assumption of equilibrium. However, these…

Astrophysics of Galaxies · Physics 2019-07-02 G. Iorio , C. Nipoti , G. Battaglia , A. Sollima

We present a new homogeneous survey of VLT/FLAMES LR8 line-of-sight radial velocities (vlos) for 1604 resolved red giant branch stars in the Sculptor dwarf spheroidal galaxy. In addition, we provide reliable Ca II triplet metallicities,…

The central area of the Sculptor dwarf galaxy was surveyed for variable stars as a side-program of the OGLE project. Light curves in the V band were obtained for 226 RR Lyr stars and for 3 anomalous cepheids. One previously unknown…

Astrophysics · Physics 2007-05-23 J. Kaluzny , M. Kubiak , M. Szymanski , A. Udalski , W. Krzeminski , M. Mateo

We propose a Stellar Locus OuTlier (SLOT) method to determine the binary fraction of main-sequence stars statistically. The method is sensitive to neither the period nor mass-ratio distributions of binaries, and able to provide model-free…

Solar and Stellar Astrophysics · Physics 2015-06-23 Haibo Yuan , Xiaowei Liu , Maosheng Xiang , Yang Huang , Bingqiu Chen

We show that measured velocity dispersions of dwarf spheroidal galaxies from about 4 to 10 km/s are unlikely to be inflated by more than 20% due to the orbital motion of binary stars, and demonstrate that the intrinsic velocity dispersions…

Astrophysics of Galaxies · Physics 2015-05-14 Quinn E. Minor , Greg Martinez , James Bullock , Manoj Kaplinghat , Ryan Trainor

We present a method to characterize statistically the parameters of a detached binary sample - binary fraction, separation distribution, and mass ratio distribution - using noisy radial-velocity data with as few as two, randomly spaced,…

Solar and Stellar Astrophysics · Physics 2015-06-04 Dan Maoz , Carles Badenes , Steven J. Bickerton

We present a new discrete chemo-dynamical axisymmetric modeling technique, which we apply to the dwarf spheroidal galaxy Sculptor. The major improvement over previous Jeans models is that realistic chemical distributions are included…

Astrophysics of Galaxies · Physics 2016-09-07 Ling Zhu , Glenn van de Ven , Laura L. Watkins , Lorenzo Posti

We report the results of a deep Chandra survey of the Sculptor dwarf spheroidal galaxy. We find five X-ray sources with $L_X$ of at least $6\times10^{33}$ ergs/sec with optical counterparts establishing them as members of Sculptor. These…

We propose a cosmological scenario for the formation and evolution of dwarf spheroidal galaxies (dSphs), satellites of the Milky Way (MW). An improved version of the semi-analytical code GAMETE (GAlaxy Merger Tree & Evolution) is used to…

Astrophysics · Physics 2009-11-13 S. Salvadori , A. Ferrara , R. Schneider

We present measurements of Fe, Mg, Si, Ca, and Ti abundances for 388 radial velocity member stars in the Sculptor dwarf spheroidal galaxy (dSph), a satellite of the Milky Way. This is the largest sample of individual alpha element (Mg, Si,…

Astrophysics of Galaxies · Physics 2014-11-20 Evan N. Kirby , Puragra Guhathakurta , Michael Bolte , Christopher Sneden , Marla C. Geha

We present an unprecedented, deep study of the primordial low-mass X-ray binary population in an isolated, lower-metallicity environment. We perform followup observations of previously-identified X-ray binary candidates in the Sculptor…

Astrophysics of Galaxies · Physics 2019-03-14 R. M. Arnason , P. Barmby , A. Bahramian , T. J. Maccarone , S. E. Zepf

We have developed spherically symmetric dynamical models of dwarf spheroidal galaxies using Schwarzschild's orbit superposition method. This type of modelling yields constraints both on the total mass distribution (e.g. enclosed mass and…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Maarten A. Breddels , A. Helmi , R. C. E. van den Bosch , G. van de Ven , G. Battaglia

The existence of blue straggler stars (BSSs) in dwarf spheroidal galaxies (dSphs) is still an open question. In fact, many BSS candidates have been observed in the Local Group dSphs, but it is unclear whether they are real BSSs or young…

Astrophysics of Galaxies · Physics 2015-05-13 M. Mapelli , E. Ripamonti , G. Battaglia , E. Tolstoy , M. J. Irwin , B. Moore , S. Sigurdsson

We present VLT/FLAMES spectroscopic observations (R~6500) in the CaII triplet region for 470 probable kinematic members of the Sculptor (Scl) dwarf spheroidal galaxy. The accurate velocities (+- 2 km/s) and large area coverage of Scl allow…

Astrophysics · Physics 2009-11-13 G. Battaglia , A. Helmi , E. Tolstoy , M. Irwin , V. Hill , P. Jablonka

We demonstrate that using up to seven stellar abundance ratios can place observational constraints on the star formation histories (SFHs) of Local Group dSphs, using the Sculptor dSph as a test case. We use a one-zone chemical evolution…

Astrophysics of Galaxies · Physics 2022-02-02 Mithi A. C. de los Reyes , Evan N. Kirby , Alexander P. Ji , Evan H. Nuñez

We present the identification of 634 variable stars in the Milky Way dSph satellite Sculptor based on archival ground-based optical observations spanning $\sim$24 years and covering $\sim$ 2.5 deg$^2$. We employed the same methodologies as…

In this contribution initial results are presented from a program to study in detail the stellar populations of dwarf Spheroidal (dSph) galaxies in three nearby groups. The long-term aim of the program is to assess the influence of…

Astrophysics · Physics 2009-11-11 G. S. Da Costa

We have performed the first detailed simulation of the horizontal branch of the Sculptor dwarf spheroidal galaxy by means of synthetic modelling techniques,taking consistently into account the star formation history and metallicity…

Astrophysics of Galaxies · Physics 2015-06-17 Maurizio Salaris , Thomas de Boer , Eline Tolstoy , Giuliana Fiorentino , Santi Cassisi