---
author:
- Dong Gao
- 'Yan-Chun Liang'
- 'Shun-Fang Liu'
- 'Guo-Hu Zhong'
- 'Xiao-Yan Chen'
- 'Yan-Bin Yang'
- Francois Hammer
- 'Guo-Chao Yang'
- 'Li-Cai Deng'
- 'Jing-Yao Hu'
title: 'Multiwavelength study of nearly face-on low surface brightness disk galaxies '
---

Introduction {#sect:intro}
============

Low Surface Brightness Galaxies (LSBGs) were often hard to find owing to their faintness compared with the night sky, thus their properties were seldom studied and their contribution to the galaxy population were underestimated for a long time. However, it has been suggested that LSBGs may comprise up to 1/2 of the local galaxy population (McGaugh, Bothun & Schombert 1995).

An initial quantitative study about LSBGs was done by Freeman (1970), who noticed that the central surface brightness of their 28 out of 36 disc galaxies fell within a rather narrow range, $\mu_{0}$(B)=21.65 $\pm$ 0.3 mag arcsec$^{-2}$. This could be caused by selection effects (Disney 1976; Zwicky 1957). Since then, many efforts have been made to search for more LSBGs from surveys (see the reviews by Bothun, Impey, McGaugh 1997; Impey & Bothun 1997; and the introduction part in Zhong et al. 2008). These include giant LSBGs (Sprayberry et al. 1995), red 