Blue straggler stars in dwarf spheroidal galaxies - II. Sculptor and Fornax
| Autor: | Michela Mapelli, Ben Moore, E. Ripamonti, Mike Irwin, Steinn Sigurdsson, Eline Tolstoy, Giuseppina Battaglia |
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| Přispěvatelé: | University of Zurich, Mapelli, M, Kapteyn Astronomical Institute |
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
530 Physics
Population FOS: Physical sciences galaxies: individual: Fornax M3 Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Blue straggler Luminosity STELLAR POPULATIONS VARIABLE-STARS 1912 Space and Planetary Science galaxies: individual: Sculptor GALACTIC GLOBULAR-CLUSTERS Astrophysics::Solar and Stellar Astrophysics GIANT BRANCH STARS education Solar and Stellar Astrophysics (astro-ph.SR) Astrophysics::Galaxy Astrophysics CCD PHOTOMETRY Physics FORMATION HISTORY education.field_of_study Star formation Local Group Astronomy and Astrophysics galaxies: dwarf Horizontal branch Astrophysics - Astrophysics of Galaxies Galaxy Stars Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) 10231 Institute for Computational Science blue stragglers 3103 Astronomy and Astrophysics stellar dynamics Astrophysics::Earth and Planetary Astrophysics RADIAL-DISTRIBUTION Blue stragglers Galaxies: dwarf Galaxies: individual: Fornax Galaxies: individual: Sculptor Stellar dynamics ISOCHRONES LOCAL GROUP |
| Zdroj: | Monthly Notices of the Royal Astronomical Society, 396(3), 1771-1782. Oxford University Press |
| ISSN: | 0035-8711 |
| Popis: | 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 stars. Shedding light on the nature of these BSS candidates is crucial, in order to understand the star formation history of dSphs. In this paper, we consider BSS candidates in Sculptor and Fornax. In Fornax there are strong hints that the BSS population is contaminated by young stars, whereas in Sculptor there is no clear evidence of recent star formation. We derive the radial and luminosity distribution of BSS candidates from wide field imaging data extending beyond the nominal tidal radius of these galaxies. The observations are compared with the radial distribution of BSSs expected from dynamical simulations. In Sculptor the radial distribution of BSS candidates is consistent with that of red horizontal branch (RHB) stars and is in agreement with theoretical expectations for BSSs generated via mass transfer in binaries. On the contrary, in Fornax the radial distribution of BSS candidates is more concentrated than that of all the considered stellar populations. This result supports the hypothesis that most of BSS candidates in Fornax are young stars and is consistent with previous studies. 14 pages, 10 figures, accepted for publication in MNRAS |
| Databáze: | OpenAIRE |
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