The anatomy of the NGC 5044 group - II. Stellar populations and star-formation histories - Astrophysics > Cosmology and Nongalactic AstrophysicsReportar como inadecuado




The anatomy of the NGC 5044 group - II. Stellar populations and star-formation histories - Astrophysics > Cosmology and Nongalactic Astrophysics - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: The distribution of galaxy properties in groups and clusters holds importantinformation on galaxy evolution and growth of structure in the Universe. Whileclusters have received appreciable attention in this regard, the role of groupsas fundamental to formation of the present day galaxy population has remainedrelatively unaddressed. Here we present stellar ages, metallicities andalpha-element abundances derived using Lick indices for 67 spectroscopicallyconfirmed members of the NGC 5044 galaxy group with the aim of shedding lighton galaxy evolution in the context of the group environment.We find that galaxies in the NGC 5044 group show evidence for a strongrelationship between stellar mass and metallicity, consistent with theircounterparts in both higher and lower mass groups and clusters. Galaxies showno clear trend of age or alpha-element abundance with mass, but these data forma tight sequence when fit simultaneously in age, metallicity and stellar mass.In the context of the group environment, our data support the tidal disruptionof low-mass galaxies at small group-centric radii, as evident from an apparentlack of galaxies below ~10^9 M sun within ~100 kpc of the brightest groupgalaxy. Using a joint analysis of absorption- and emission-line metallicities,we are able to show that the star-forming galaxy population in the NGC 5044group appears to require gas removal to explain the ~1.5 dex offset betweenabsorption- and emission-line metallicities observed in some cases. Acomparison with other stellar population properties suggests that this gasremoval is dominated by galaxy interactions with the hot intragroup medium.



Autor: J. Trevor Mendel, Robert N. Proctor, Jesper Rasmussen, Sarah Brough, Duncan A. Forbes

Fuente: https://arxiv.org/



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