Astron. Astrophys. 338, 435-441 (1998)

Are the Bulge C - stars related to the Sagittarius dwarf galaxy?

II. Metallicity - a link with the galactic disc

Yuen K. Ng ^*

Padova Astronomical Observatory, Vicolo dell'Osservatorio 5, I-35122 Padua, Italy (yuen@pd.astro.it)

Received 20 April 1998 / Accepted 23 July 1998

Abstract

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.

Key words: stars: carbon stars: evolution galaxies: individual: Sagittarius dwarf galaxies: interactions

* Present address: Space Research Organisation Netherlands (SRON), Sorbonnelaan 2, 3584 CA Utrecht, The Netherlands

© European Southern Observatory (ESO) 1998

Online publication: September 14, 1998

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