2015/03/27 by A. E. Sansom, J. J. Thirlwall, Jordan J. Thirlwall +5
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Dwarf galaxy #Dwarf spheroidal galaxy #Elliptical galaxy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy merger #Lenticular galaxy #Luminosity #Luminous infrared galaxy #Physics #Star formation #Stellar population #Stellar, planetary, and galactic studies #astro-ph.GA
paper · pdf · doi:10.1093/mnras/stv690
12 pages, 7 figures, 4 tables, accepted for publication in MNRAS
arxiv created 2015/03/27 · openalex publication_date 2015/04/24 · arxiv updated 2015/06/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Low-luminosity galaxies may be the building blocks of more luminous systems. Southern African Large Telescope observations of the low-luminosity, early-type galaxy NGC 59 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 [α/Fe] ratio is subsolar, which indicates an extended star formation history in NGC 59. 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.