Open AccessThe star formation histories of low surface brightness galaxies
Author(s) -
Bell Eric F.,
Barnaby David,
Bower Richard G.,
De Jong Roelof S.,
Harper Doyal A.,
Hereld Mark,
Loewenstein Robert F.,
Rauscher Bernard J.
Publication year - 2000
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2000.03180.x
Subject(s) - physics , surface brightness , metallicity , astrophysics , star formation , galaxy , astronomy , stellar population , surface brightness fluctuation , stellar mass , stars , lenticular galaxy
We have performed deep imaging of a diverse sample of 26 low surface brightness galaxies (LSBGs) in the optical and the near‐infrared. Using stellar population synthesis models, we find that it is possible to place constraints on the ratio of young to old stars (which we parametrize in terms of the average age of the galaxy), as well as the metallicity of the galaxy, using optical and near‐infrared colours. LSBGs have a wide range of morphologies and stellar populations, ranging from older, high‐metallicity earlier types to much younger and lower‐metallicity late‐type galaxies. Despite this wide range of star formation histories, we find that colour gradients are common in LSBGs. These are most naturally interpreted as gradients in mean stellar age, with the outer regions of LSBGs having lower ages than their inner regions. In an attempt to understand what drives the differences in LSBG stellar populations, we compare LSBG average ages and metallicities with their physical parameters. Strong correlations are seen between an LSBG’s star formation history and its K ‐band surface brightness, K ‐band absolute magnitude and gas fraction. These correlations are consistent with a scenario in which the star formation history of an LSBG primarily correlates with its surface density and its metallicity correlates with both its mass and its surface density.