Are the Bulge C – stars related to the Sagittarius dwarf galaxy? II. Metallicity – a link with the galactic disc
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چکیده
The photometric estimate of the metallicity and the age of the Azzopardi et al. (1991) carbon stars (Ng 1997) is revised to respectively Z ' 0.004 and ∼ 0.1 Gyr. Under the hypothesis that the carbon stars are located at a distance related to the Sagittarius dwarf galaxy, the broad velocity dispersion of the stars can only be explained if they were formed out of Galactic material during a recent crossing of the Sagittarius dwarf galaxy through the Galactic plane.
منابع مشابه
Constraints on the origin of Manganese from the composition of the Sagittarius Dwarf Spheroidal Galaxy and the Galactic Bulge
The trend of [Mn/Fe] in the Galactic bulge follows the solar-neighborhood relation, but most stars in the Sagittarius dwarf spheroidal galaxy (Sgr dSph) show [Mn/Fe] deficient by ∼0.2 dex. This leads us to conclude that the Mn yields from both type Ia and type II SNe are metallicity-dependent. Our observations militate against the idea, suggested by Gratton, that Mn is over-produced by type Ia ...
متن کاملAre the Bulge C – stars related to the Sagittarius dwarf galaxy?
Part of the mystery around the Bulge carbon stars from Azzopardi et al. (1991) is solved, if they are related to the Sagittarius dwarf galaxy. The carbon stars are in that case not metal-rich as previously thought, but they have a metallicity comparable to the LMC, with an age between 0.1 – 1 Gyr. A significant fraction of the carbon stars still have luminosities fainter than the lower LMC limi...
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متن کاملAre the Bulge C– stars in the Sagittarius dwarf galaxy?
Part of the mystery around the Bulge carbon stars from Azzopardi et al. (1991) is solved, when they belong to the Sagittarius dwarf galaxy. The carbon stars are not metal-rich as previously thought, but they have a metallicity comparable to the LMC, with an age between 0.1 – 1 Gyr. A significant fraction of the Sagittarius dwarf carbon stars have luminosities fainter than the lower LMC and SMC ...
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The photometric estimate of the metallicity and the age of the Azzopardi et al. (1991) carbon stars (Ng 1997) is revised to respectively Z≃0.004 and ∼0.1 Gyr. Under the hypothesis that the carbon stars are located at a distance related to the Sagittarius dwarf galaxy, the broad velocity dispersion of the stars can only be explained if they were formed out of Galactic material during a recent cr...
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تاریخ انتشار 1998