Weak Galactic halo-Fornax dSph connection from RR Lyrae stars
| العنوان: | Weak Galactic halo-Fornax dSph connection from RR Lyrae stars |
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| المؤلفون: | Davide Massari, Matteo Monelli, Vittorio F. Braga, Giuliana Fiorentino, Giuseppe Bono, Carme Gallart, C. E. Martínez-Vázquez, Massimo Dall'Ora, Peter B. Stetson, Edouard J. Bernard |
| المساهمون: | Astronomy |
| المصدر: | Astronomy & astrophysics, 599:A125. EDP Sciences |
| بيانات النشر: | EDP Sciences, 2017. |
| سنة النشر: | 2017 |
| مصطلحات موضوعية: | stars: variables: RR Lyrae, 010504 meteorology & atmospheric sciences, galaxies: individual: Fornax dSph, METAL-POOR STARS, GRAVITATIONAL LENSING EXPERIMENT, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, RR Lyrae variable, 01 natural sciences, ACS LCID PROJECT, Galactic halo, VARIABLE-STARS, GLOBULAR-CLUSTERS, 0103 physical sciences, Galaxy formation and evolution, LOCAL GROUP GALAXIES, Astrophysics::Solar and Stellar Astrophysics, CHEMICAL EVOLUTION HISTORY, Large Magellanic Cloud, OGLE-III CATALOG, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Dwarf galaxy, Physics, DWARF SPHEROIDAL GALAXY, Star formation, Settore FIS/05, SCULPTOR DSPH, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Dwarf spheroidal galaxy, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Earth and Planetary Astrophysics, galaxies: evolution |
| الوصف: | For the first time accurate pulsation properties of the ancient variable stars of the Fornax dwarf spheroidal galaxy (dSph) are discussed in the broad context of galaxy formation and evolution. Homogeneous multi-band $BVI$ optical photometry of spanning {\it twenty} years has allowed us to identify and characterize more than 1400 RR Lyrae stars (RRLs) in this galaxy. Roughly 70\% are new discoveries. We investigate the period-amplitude distribution and find that Fornax shows a lack of High Amplitude (A$_V\gsim$0.75 mag) Short Period fundamental-mode RRLs (P$\lsim$0.48 d, HASPs). These objects occur in stellar populations more metal-rich than [Fe/H]$\sim$-1.5 and they are common in the Galactic halo (Halo) and in globulars. This evidence suggests that old (age older than 10 Gyr) Fornax stars are relatively metal-poor. A detailed statistical analysis of the role of the present-day Fornax dSph in reproducing the Halo period distribution shows that it can account for only a few to 20\% of the Halo when combined with RRLs in massive dwarf galaxies (Sagittarius dSph, Large Magellanic Cloud). This finding indicates that Fornax-like systems played a minor role in building up the Halo when compared with massive dwarfs. We also discuss the occurrence of HASPs in connection with the luminosity and the early chemical composition of nearby dwarf galaxies. We find that, independently of their individual star formation histories, bright (M$_V\lsim$-13.5 mag) galaxies have HASPs, whereas faint ones (M$_V\gsim$-11 mag) do not. Interestingly enough, Fornax belongs to a luminosity range (--11$ Comment: 7 pages, 5 figures, A&A, accepted |
| وصف الملف: | application/pdf |
| اللغة: | English |
| تدمد: | 1432-0746 0004-6361 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::94110d1d46823557c5151bde90d37427Test https://doi.org/10.1051/0004-6361/201629501Test |
| حقوق: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....94110d1d46823557c5151bde90d37427 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 14320746 00046361 |
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