Abundance ratios in dwarf elliptical galaxies
Den Brok, M.
MetadataShow full item record
We determine abundance ratios of 37 dwarf ellipticals (dEs) in the nearby Virgo cluster. This sample is representative of the early-type population of galaxies in the absolute magnitude range −19.0 < Mr < −16.0. We analyse their absorption line-strength indices by means of index–index diagrams and scaling relations and use the stellar population models to interpret them. We present ages, metallicities, and abundance ratios obtained from these dEs within an aperture size of Re/8.We calculate [Na/Fe] from NaD, [Ca/Fe] from Ca4227, and [Mg/Fe] from Mgb. We find that [Na/Fe] is underabundant with respect to solar, whereas [Mg/Fe] is around solar. This is exactly opposite to what is found for giant ellipticals, but follows the trend with metallicity found previously for the Fornax dwarf NGC 1396. We discuss possible formation scenarios that can result in such elemental abundance patterns, and we speculate that dEs have disc-like star formation history (SFH) favouring them to originate from late-type dwarfs or small spirals. Na-yields appear to be very metal-dependent, in agreement with studies of giant ellipticals, probably due to the large dependence on the neutron-excess in stars. We conclude that dEs have undergone a considerable amount of chemical evolution, they are therefore not uniformly old, but have extended SFH, similar to many of the Local Group galaxies
Showing items related by title, author, creator and subject.
Groenewald, D.N.; Loubser, S.I. (Oxford Univ Press, 2014)This article is devoted to the study of the central stellar populations of the brightest cluster galaxies (BCGs). High signal-to-noise ratio, long-slit spectra for a sample of 39 galaxies were fitted against two stellar ...
Loubser, S.I. (Oxford Univ Press, 2014)We present detailed, high spatial and spectral resolution, long-slit observations of four central cluster galaxies (CCGs; Abell 0085, 0133, 0644 and Ophiuchus) recently obtained on the Southern African Large Telescope. ...
Loubser, S.I.; Soechting, I.K. (Oxford Univ Press, 2013)We present detailed integral field unit observations of the central few kiloparsecs of the ionized nebulae surrounding four active central cluster galaxies (CCGs) in cooling flow clusters (Abell 0496, 0780, 1644 and ...