The exotic chemical composition of the Sagittarius dwarf Spheroidal galaxy

Details The exotic chemical composition of the Sagittarius dwarf Spheroidal galaxy The exotic chemical composition of the Sagittarius dwarf Spheroidal galaxy

2006-12-05

arxiv.org/abs/astro-ph/0612125v1

Astronomy and Astrophysics

Astrophysics

21 pages, 5 figures, accepted by A&A

Scientific paper

10.1051/0004-6361:20066385

The Sagittarius dwarf Spheroidal galaxy is the nearest neighbor of the Milky Way. Moving along a short period quasi-polar orbit within the Halo, it is being destroyed by the tidal interaction with our Galaxy, losing its stellar content along a huge stellar stream. We study the detailed chemical composition of 12 giant stars in the Sagittarius dwarf Spheroidal main body, together with 5 more in the associated globular cluster Terzan 7 by means of high resolution VLT-UVES spectra. Abundances are derived for up to 21 elements from O to Nd, by fitting lines EW or line profiles against ATLAS 9 model atmospheres and SYNTHE spectral syntheses calculated ad-hoc. Temperatures are derived from (V-I)_0 or (B-V)_0 colors, gravities from Fe I - Fe II ionization equilibrium. The metallicity of the observed stars is between [Fe/H]=-0.9 and 0. We detected a highly peculiar ``chemical signature'', with undersolar alpha elements, Na, Al, Sc, V, Co, Ni, Cu and Zn among others, and overabundant La, Ce and Nd. Many of these abundance ratios (in particular light-odd elements and iron peak ones) are strongly at odds with what is observed within the Milky Way, they thus may be a very useful tool to recognize populations originated within the Sagittarius dwarf. This can be clearly seen in the case of the globular Palomar 12, which is believed to have been stripped from Sagittarius: the cluster shows precisely the same chemical ``oddities'', thus finally confirming its extragalactic origin.

Affiliated with

Also associated with

No associations

Rating

The exotic chemical composition of the Sagittarius dwarf Spheroidal galaxy does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The exotic chemical composition of the Sagittarius dwarf Spheroidal galaxy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The exotic chemical composition of the Sagittarius dwarf Spheroidal galaxy will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-717371