Chemical evolution and stellar populations in the Sagittarius dwarf Spheroidal Galaxy

L. Sbordone, P. Bonifacio, G. Giuffrida, G. Marconi, L. Monaco, S. Zaggia

Resultado de la investigación: Article

Resumen

The closest neighbour of the Milky Way (MW) the Sagittarius dwarf Spheroidal Galaxy (Sgr dSph) is being tidally destroyed by the interaction with our Galaxy, losing its stellar content along a huge stream clearly detectable within the Halo. This makes the Sgr dSph an ideal laboratory to study at the same time the chemical evolution of dwarf galaxies and their role in building bigger structures such as the MW. Since some years we are studying the stellar populations of the Sgr main body and stream, with particular attention to their detailed chemical composition. We collected detailed abundances (up to 22 elements, O to Eu) for 27 stars in the Sgr dSph main body, 5 in the associated globular cluster Terzan 7, and 12 more in the trailing Sgr tidal arm (UVES@VLT and SARG@TNG data). We are also conducting a large FLAMES@VLT chemical and dynamical analysis aimed at obtaining metallicities, alpha-elements content and radial velocities from automated analysis of the spectra. Finally, we just completed the first large scale photometric and spectroscopic survey of the stellar populations across all the dSph main body extension with VIMOS@VLT, aimed at exploring the variations in stellar populations and at deriving radial velocity memberships for future high resolution spectroscopic analysis. The picture emerging from all these studies portraits a large and extremely complex object, with signs of a long and still unclear evolution. Metallicity varies across three orders of magnitude ([Fe/H] from 3 to 0), CMDs change surprisingly from the core to the outskirts of the galaxy, and the chemical composition of the most metal rich objects show a very characteristic signature, with underabundant alpha elements, deficient Na, underabundant Fe-peak Mn, Co, Ni, Cu and Zn, and strongly enhanced n-capture elements La and Nd. This highly peculiar signature can also be effectively used to recognized stripped populations lost by Sgr in favour of the MW system, as clearly showed by the globular Palomar 12, which shows the same chemical anomalies detected in Sgr dSph.

Idioma originalEnglish
Páginas (desde-hasta)330
Número de páginas1
PublicaciónProceedings of the International Astronomical Union
Volumen2
N.ºS235
DOI
EstadoPublished - ago 2006

Huella dactilar

Galaxies
chemical evolution
dwarf galaxies
chemical composition
radial velocity
metallicity
signatures
galaxies
anomaly
spectroscopic analysis
globular clusters
chemical analysis
metal
Spectroscopic analysis
emerging
halos
analysis
chemical
Chemical analysis
anomalies

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)
  • Aerospace Engineering
  • Astronomy and Astrophysics

Citar esto

Sbordone, L. ; Bonifacio, P. ; Giuffrida, G. ; Marconi, G. ; Monaco, L. ; Zaggia, S. / Chemical evolution and stellar populations in the Sagittarius dwarf Spheroidal Galaxy. En: Proceedings of the International Astronomical Union. 2006 ; Vol. 2, N.º S235. pp. 330.
@article{38155759b13343a7b769874a237f7a02,
title = "Chemical evolution and stellar populations in the Sagittarius dwarf Spheroidal Galaxy",
abstract = "The closest neighbour of the Milky Way (MW) the Sagittarius dwarf Spheroidal Galaxy (Sgr dSph) is being tidally destroyed by the interaction with our Galaxy, losing its stellar content along a huge stream clearly detectable within the Halo. This makes the Sgr dSph an ideal laboratory to study at the same time the chemical evolution of dwarf galaxies and their role in building bigger structures such as the MW. Since some years we are studying the stellar populations of the Sgr main body and stream, with particular attention to their detailed chemical composition. We collected detailed abundances (up to 22 elements, O to Eu) for 27 stars in the Sgr dSph main body, 5 in the associated globular cluster Terzan 7, and 12 more in the trailing Sgr tidal arm (UVES@VLT and SARG@TNG data). We are also conducting a large FLAMES@VLT chemical and dynamical analysis aimed at obtaining metallicities, alpha-elements content and radial velocities from automated analysis of the spectra. Finally, we just completed the first large scale photometric and spectroscopic survey of the stellar populations across all the dSph main body extension with VIMOS@VLT, aimed at exploring the variations in stellar populations and at deriving radial velocity memberships for future high resolution spectroscopic analysis. The picture emerging from all these studies portraits a large and extremely complex object, with signs of a long and still unclear evolution. Metallicity varies across three orders of magnitude ([Fe/H] from 3 to 0), CMDs change surprisingly from the core to the outskirts of the galaxy, and the chemical composition of the most metal rich objects show a very characteristic signature, with underabundant alpha elements, deficient Na, underabundant Fe-peak Mn, Co, Ni, Cu and Zn, and strongly enhanced n-capture elements La and Nd. This highly peculiar signature can also be effectively used to recognized stripped populations lost by Sgr in favour of the MW system, as clearly showed by the globular Palomar 12, which shows the same chemical anomalies detected in Sgr dSph.",
keywords = "Galaxies: abundances, Galaxies: dwarf, Galaxies: individual: Sgr dSph, Galaxies: stellar content, Galaxy: halo, Stars: abundances, Stars: kinematics",
author = "L. Sbordone and P. Bonifacio and G. Giuffrida and G. Marconi and L. Monaco and S. Zaggia",
year = "2006",
month = "8",
doi = "10.1017/S1743921306010027",
language = "English",
volume = "2",
pages = "330",
journal = "Proceedings of the International Astronomical Union",
issn = "1743-9213",
publisher = "Cambridge University Press",
number = "S235",

}

Chemical evolution and stellar populations in the Sagittarius dwarf Spheroidal Galaxy. / Sbordone, L.; Bonifacio, P.; Giuffrida, G.; Marconi, G.; Monaco, L.; Zaggia, S.

En: Proceedings of the International Astronomical Union, Vol. 2, N.º S235, 08.2006, p. 330.

Resultado de la investigación: Article

TY - JOUR

T1 - Chemical evolution and stellar populations in the Sagittarius dwarf Spheroidal Galaxy

AU - Sbordone, L.

AU - Bonifacio, P.

AU - Giuffrida, G.

AU - Marconi, G.

AU - Monaco, L.

AU - Zaggia, S.

PY - 2006/8

Y1 - 2006/8

N2 - The closest neighbour of the Milky Way (MW) the Sagittarius dwarf Spheroidal Galaxy (Sgr dSph) is being tidally destroyed by the interaction with our Galaxy, losing its stellar content along a huge stream clearly detectable within the Halo. This makes the Sgr dSph an ideal laboratory to study at the same time the chemical evolution of dwarf galaxies and their role in building bigger structures such as the MW. Since some years we are studying the stellar populations of the Sgr main body and stream, with particular attention to their detailed chemical composition. We collected detailed abundances (up to 22 elements, O to Eu) for 27 stars in the Sgr dSph main body, 5 in the associated globular cluster Terzan 7, and 12 more in the trailing Sgr tidal arm (UVES@VLT and SARG@TNG data). We are also conducting a large FLAMES@VLT chemical and dynamical analysis aimed at obtaining metallicities, alpha-elements content and radial velocities from automated analysis of the spectra. Finally, we just completed the first large scale photometric and spectroscopic survey of the stellar populations across all the dSph main body extension with VIMOS@VLT, aimed at exploring the variations in stellar populations and at deriving radial velocity memberships for future high resolution spectroscopic analysis. The picture emerging from all these studies portraits a large and extremely complex object, with signs of a long and still unclear evolution. Metallicity varies across three orders of magnitude ([Fe/H] from 3 to 0), CMDs change surprisingly from the core to the outskirts of the galaxy, and the chemical composition of the most metal rich objects show a very characteristic signature, with underabundant alpha elements, deficient Na, underabundant Fe-peak Mn, Co, Ni, Cu and Zn, and strongly enhanced n-capture elements La and Nd. This highly peculiar signature can also be effectively used to recognized stripped populations lost by Sgr in favour of the MW system, as clearly showed by the globular Palomar 12, which shows the same chemical anomalies detected in Sgr dSph.

AB - The closest neighbour of the Milky Way (MW) the Sagittarius dwarf Spheroidal Galaxy (Sgr dSph) is being tidally destroyed by the interaction with our Galaxy, losing its stellar content along a huge stream clearly detectable within the Halo. This makes the Sgr dSph an ideal laboratory to study at the same time the chemical evolution of dwarf galaxies and their role in building bigger structures such as the MW. Since some years we are studying the stellar populations of the Sgr main body and stream, with particular attention to their detailed chemical composition. We collected detailed abundances (up to 22 elements, O to Eu) for 27 stars in the Sgr dSph main body, 5 in the associated globular cluster Terzan 7, and 12 more in the trailing Sgr tidal arm (UVES@VLT and SARG@TNG data). We are also conducting a large FLAMES@VLT chemical and dynamical analysis aimed at obtaining metallicities, alpha-elements content and radial velocities from automated analysis of the spectra. Finally, we just completed the first large scale photometric and spectroscopic survey of the stellar populations across all the dSph main body extension with VIMOS@VLT, aimed at exploring the variations in stellar populations and at deriving radial velocity memberships for future high resolution spectroscopic analysis. The picture emerging from all these studies portraits a large and extremely complex object, with signs of a long and still unclear evolution. Metallicity varies across three orders of magnitude ([Fe/H] from 3 to 0), CMDs change surprisingly from the core to the outskirts of the galaxy, and the chemical composition of the most metal rich objects show a very characteristic signature, with underabundant alpha elements, deficient Na, underabundant Fe-peak Mn, Co, Ni, Cu and Zn, and strongly enhanced n-capture elements La and Nd. This highly peculiar signature can also be effectively used to recognized stripped populations lost by Sgr in favour of the MW system, as clearly showed by the globular Palomar 12, which shows the same chemical anomalies detected in Sgr dSph.

KW - Galaxies: abundances

KW - Galaxies: dwarf

KW - Galaxies: individual: Sgr dSph

KW - Galaxies: stellar content

KW - Galaxy: halo

KW - Stars: abundances

KW - Stars: kinematics

UR - http://www.scopus.com/inward/record.url?scp=36949025227&partnerID=8YFLogxK

U2 - 10.1017/S1743921306010027

DO - 10.1017/S1743921306010027

M3 - Article

AN - SCOPUS:36949025227

VL - 2

SP - 330

JO - Proceedings of the International Astronomical Union

JF - Proceedings of the International Astronomical Union

SN - 1743-9213

IS - S235

ER -