S. Caliskan, N. Christlieb, K. E. Grebel
We determine the elemental abundances of nine red giant stars belonging to
Palomar 14 (Pal 14). Pal 14 is an outer halo globular cluster (GC) at a
distance of \sim 70 kpc. Our abundance analysis is based on high-resolution
spectra and one-dimensional stellar model atmospheres.We derived the abundances
for the iron peak elements Sc, V, Cr, Mn, Co, Ni, the {\alpha}-elements O, Mg,
Si, Ca, Ti, the light odd element Na, and the neutron-capture elements Y, Zr,
Ba, La, Ce, Nd, Eu, Dy, and Cu. Our data do not permit us to investigate light
element (i.e., O to Mg) abundance variations. The neutron-capture elements show
an r-process signature. We compare our measurements with the abundance ratios
of inner and other outer halo GCs, halo field stars, GCs of recognized
extragalactic origin, and stars in dwarf spheroidal galaxies (dSphs). The
abundance pattern of Pal 14 is almost identical to those of Pal 3 and Pal 4,
the next distant members of the outer halo GC population after Pal 14. The
abundance pattern of Pal 14 is also similar to those of the inner halo GCs,
halo field stars, and GCs of recognized extragalactic origin, but differs from
what is customarily found in dSphs field stars. The abundance properties of Pal
14 as well as those of the other outer halo GCs are thus compatible with an
accretion origin from dSphs. Whether or not GC accretion played a role, it
seems that the formation conditions of outer halo GCs and GCs in dSphs were
similar.
View original:
http://arxiv.org/abs/1110.5151
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