Tuesday, March 12, 2013

Individual Alpha Elements, C, N, and Ba in Early Type Galaxies. (arXiv:1303.2603v1 [astro-ph.CO])

Individual Alpha Elements, C, N, and Ba in Early Type Galaxies. (arXiv:1303.2603v1 [astro-ph.CO]):
Spectral data on early type galaxies is analyzed for chemical abundance with
an emphasis on obtaining detailed abundances for the elements O and Si in
addition to C, N, Na, Mg, Ca, Fe, and Ba. The abundance trends with velocity
dispersion fit preconceptions based upon previous Mg conclusions, namely that
larger galaxies have a higher alpha element to iron peak ratio indicative of a
higher ratio of Type II to Type Ia supernova products. The heaviest alpha
elements, Ca and Ti, do not participate in this trend, although this fact does
not necessarily alter the basic picture given the uncertainties in
nucleosynthetic yields. Elements that likely have significant contributions
from intermediate-mass stars, namely C, N, and Ba, also gain ground relative to
Fe in massive galaxies at a modest level, with the Ba conclusion uncertain from
our data alone.

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