Environment, morphology, and stellar populations of bulgeless low surface-brightness galaxies

¹ Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, 100012 Beijing, PR China
e-mail: xshao@bao.ac.cn
² Laboratoire GEPI, Observatoire de Paris, CNRS-UMR 8111, Univ. Paris Diderot, Sorbonne Paris Cité, 5 place Jules Janssen, 92195 Meudon, France
³ University of the Chinese Academy of Sciences, 100049 Beijing, PR China

Received: 3 February 2015
Accepted: 22 April 2015

Abstract

Based on the Sloan Digital Sky Survey DR 7, we investigate the environment, morphology, and stellar population of bulgeless low surface-brightness (LSB) galaxies in a volume-limited sample with redshift ranging from 0.024 to 0.04 and M_r≤−18.8. The local density parameter Σ₅ is used to trace their environments. We find that, for bulgeless galaxies, the surface brightness does not depend on the environment. The stellar populations are compared for bulgeless LSB galaxies in different environments and for bulgeless LSB galaxies with different morphologies. The stellar populations of LSB galaxies in low-density regions are similar to those of LSB galaxies in high-density regions. Irregular LSB galaxies have more young stars and are more metal-poor than regular LSB galaxies. These results suggest that the evolution of LSB galaxies may be driven by their dynamics, including mergers rather than by their large-scale environment.