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.

arXiv comment12 pages, 7 figures, 4 tables, accepted for publication in MNRAS

References in corpus (44)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• Stellar population synthesis at the resolution of 2003
• The Dust Content and Opacity of Actively Star-Forming Galaxies
• Parametric Recovery of Line-of-Sight Velocity Distributions from Absorption-Line Spectra of Galaxies via Penalized Likelihood
• The epochs of early-type galaxy formation as a function of environment
• Star Formation Histories, Abundances and Kinematics of Dwarf Galaxies in the Local Group
• Evolutionary Stellar Population Synthesis with MILES. Part I: The Base Models and a New Line Index System
• The SAURON project - V. Integral-field emission-line kinematics of 48 elliptical and lenticular galaxies
• An updated MILES stellar library and stellar population models
• The Third Data Release of the Sloan Digital Sky Survey
• The chemical composition of metal-poor emission-line galaxies in the Data Release 3 of the Sloan Digital Sky Survey
• Heavy element abundances in blue compact galaxies
• 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
• Early-Type Galaxy Archeology: Ages, Abundance Ratios, and Effective Temperatures from Full-Spectrum Fitting
• First science with SALT: peering at the accreting polar caps of the eclipsing polar SDSS J015543.40+002807.2
• A comparison of stellar populations in galaxy populations across a wide range of Hubble types
• Strong Emission Line HII Galaxies in the Sloan Digital Sky Survey. I. Catalog of DR1 Objects with Oxygen Abundances from Te easurements
• Age and metallicity gradients in early-type galaxies: A dwarf to giant sequence
• 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 sensitivity of Lick indices to abundance variations
• Spectrophotometry of Sextans A and B: Chemical Abundances of HII Regions and Planetary Nebulae
• Chemical element ratios of SDSS early-type galaxies
• The APM Bright Galaxy Catalogue
• Star formation properties in the Local Volume galaxies via $H\alpha$ and FUV fluxes
• The Importance of Nebular Continuum and Line Emission in Observations of Young Massive Star Clusters
• Star Formation in Sculptor Group Dwarf Irregular Galaxies and the Nature of "Transition" Galaxies
• Better age estimations using UV-optical colours: breaking the age-metallicity degeneracy
• The metallicity extremes of the Sagittarius dSph using SALT spectroscopy of PNe
• The chemical evolution of galaxies within the IGIMF theory: the [alpha/Fe] ratios and downsizing
• GalICS II: the [alpha/Fe]-mass relation in elliptical galaxies
• Galaxy And Mass Assembly (GAMA): The mass-metallicity relationship
• Detection of neutral hydrogen in early-type dwarf galaxies of the Sculptor Group
• Luminosity-Metallicity Relation for dIrr Galaxies in the Near-Infrared
• Formation and Evolution of Early-Type Galaxies. III Star formation history as a function of mass and over-density
• Tests of model predictions for the response of stellar spectra and absorption line indices to element abundance variations
• Identifying the progenitor set of present-day early-type galaxies: a view from the standard model
• The stellar populations of early-type galaxies -- II. The effects of environment and mass
• Bimodality in low luminosity E and S0 galaxies
• HI Detection in two Dwarf S0 Galaxies in Nearby Groups: ESO384-016 and NGC 59
• Nature vs. nurture in the low-density environment: structure and evolution of early-type dwarf galaxies in poor groups
• Photometric Properties of Six Local Volume Dwarf Galaxies from Deep Near-Infrared Observations