The stellar populations in the low luminosity, early-type galaxy NGC59

Abstract

Low luminosity galaxies may be the building blocks of more luminous systems. Southern African Large Telescope (SALT) observations of the low luminosity, early-type galaxy NGC59 are obtained and analysed. These data are used to measure the stellar population parameters in the centre and off-centre regions of this galaxy, in order to uncover its likely star formation history. We find evidence of older stars, in addition to young stars in the emission line regions. The metallicity of the stellar population is constrained to be [Z/H] ~ -1.1 to -1.6, which is extremely low, even for this low luminosity galaxy, since it is not classed as a dwarf spheroidal galaxy. The measured [alpha/Fe] ratio is sub-solar, which indicates an extended star formation history in NGC59. If such objects formed the building blocks of more massive, early-type galaxies, then they must have been gaseous mergers, rather than dry mergers, in order to increase the metals to observed levels in luminous, early-type galaxies.

12 pages, 7 figures, 4 tables, accepted for publication in MNRAS

References in corpus (10)

• Evolutionary Stellar Population Synthesis with MILES. Part I: The Base Models and a New Line Index System
• Ages and metallicities of early-type galaxies in the SDSS: new insight into the physical origin of the colour-magnitude and the Mg2-sigmaV relations
• Population Synthesis in the Blue IV: Accurate Model Predictions for Lick Indices and UBV Colors in Single Stellar Populations
• First science with SALT: peering at the accreting polar caps of the eclipsing polar SDSS J015543.40+002807.2
• Measuring Ages and Elemental Abundances from Unresolved Stellar Populations: Fe, Mg, C, N, and Ca
• Dissecting the Red Sequence--I. Star Formation Histories of Quiescent Galaxies: The Color-Magnitude vs. the Color-Sigma Relation
• Galaxy And Mass Assembly (GAMA): Stellar mass functions by Hubble type
• The metallicity extremes of the Sagittarius dSph using SALT spectroscopy of PNe
• Luminosity-Metallicity Relation for dIrr Galaxies in the Near-Infrared
• Bimodality in low luminosity E and S0 galaxies