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The DART imaging and CaT survey of the Fornax dwarf spheroidal galaxy
- Source :
- Astronomy & astrophysics, 459(2), 423-440.e13. EDP Sciences
- Publication Year :
- 2006
-
Abstract
- As part of the DART project we have used the ESO/2.2m Wide Field Imager in conjunction with the VLT/FLAMES GIRAFFE spectrograph to study the detailed properties of the resolved stellar population of the Fornax dwarf spheroidal galaxy out to and beyond its tidal radius. We re-derived the structural parameters of the Fornax dwarf spheroidal using our wide field imaging covering the galaxy out to its tidal radius, and analysed the spatial distribution of the Fornax stars of different ages as selected from Colour-Magnitude Diagram analysis. We have obtained accurate velocities and metallicities from spectra in the CaII triplet wavelength region for 562 Red Giant Branch stars which have velocities consistent with membership in Fornax dwarf spheroidal. We have found evidence for the presence of at least three distinct stellar components: a young population (few 100 Myr old) concentrated in the centre of the galaxy, visible as a Main Sequence in the Colour-Magnitude Diagram; an intermediate age population (2-8 Gyr old); and an ancient population (> 10Gyr),which are distinguishable from each other kinematically, from the metallicity distribution and in the spatial distribution of stars found in the Colour-Magnitude Diagram. From our spectroscopic analysis we find that the ``metal rich'' stars ([Fe/H]> -1.3) show a less extended and more concentrated spatial distribution, and display a colder kinematics than the ``metal poor'' stars ([Fe/H<br />Comment: 32 pages, 23 figures. Accepted for publication in A&A. The data table (Table 4) will be available in electronic form after publication. The full resolution version can be downloaded from http://www.astro.rug.nl/~gbattagl/battaglia_fullres.ps
- Subjects :
- Stellar population
EXPLORING HALO SUBSTRUCTURE
Metallicity
Population
II TRIPLET
FOS: Physical sciences
Astrophysics
Astrophysics::Cosmology and Extragalactic Astrophysics
galaxies : kinematics and dynamics
01 natural sciences
galaxies : stellar content
STELLAR POPULATIONS
BRIGHTNESS PROFILES
GLOBULAR-CLUSTERS
0103 physical sciences
Astrophysics::Solar and Stellar Astrophysics
STAR-CLUSTERS
10. No inequality
education
010303 astronomy & astrophysics
Astrophysics::Galaxy Astrophysics
galaxies : dwarf
Physics
education.field_of_study
Y-2 ISOCHRONES
010308 nuclear & particles physics
Astrophysics (astro-ph)
2ND-PARAMETER PROBLEM
Astronomy and Astrophysics
galaxies : individual : Fornax
galaxies : Local Group
GIANT STARS
Accretion (astrophysics)
Galaxy
Dwarf spheroidal galaxy
Red-giant branch
Stars
stars : abundances
Space and Planetary Science
Astrophysics::Earth and Planetary Astrophysics
CLUSTER METALLICITY SCALE
Subjects
Details
- Language :
- English
- ISSN :
- 00046361
- Volume :
- 459
- Issue :
- 2
- Database :
- OpenAIRE
- Journal :
- Astronomy & astrophysics
- Accession number :
- edsair.doi.dedup.....fdfe91969db9ed160d70ece466bf7dfb