UV and NIR size of the HI selected low surface brightness galaxies

TL;DR

This study investigates the size, star formation, and stellar mass distribution of HI-selected low surface brightness galaxies using UV and NIR observations, revealing extended star formation and gas distribution compared to other galaxy types.

Contribution

It provides new measurements of UV and NIR radii for LSBGs and compares their structure with other galaxies, highlighting their extended star formation and gas distribution.

Findings

LSBGs have extended star formation structures.

Stellar mass distribution in LSBGs is similar to disk galaxies.

HI gas is distributed at larger radii, affecting star formation relations.

Abstract

How does the low surface brightness galaxies (LSBGs) form stars and assemble the stellar mass is one of the most important questions to understand the LSBG population. We select a sample of 381 HI bright LSBGs with both Far Ultraviolet (FUV) and Near Infrared (NIR) observation to investigate the star formation rate (SFR) and stellar mass scales, and the growth mode. We measure the UV and NIR radius of our sample, which represent the star-forming and stellar mass distribution scales. We also compare the UV and H band radius-stellar mass relation with the archive data, to identify the SFR and stellar mass structure difference between the LSBG population and other galaxies. Since galaxy HI mass has a tight correlation with the HI radius, we can also compare the HI and UV radii to understand the distribution of the HI gas and star formation activities. Our results show that most of the HI selected LSBGs have extended star formation structure. The stellar mass distribution of LSBGs may have a similar structure as the disk galaxies at the same stellar mass bins, while the star-forming activity of LSBGs happens at a larger radius than the high surface density galaxies, which may help to select the LSBG sample from the wide-field deep u band image survey. The HI also distributed at a larger radius, implying a steeper (or no) Kennicutt-Schmidt relation for LSBGs.