# Star Formation in Galaxies with Large Lower Surface Brightness Disks

## TL;DR

This study examines 19 large disk galaxies with intermediate surface brightness, revealing their morphology, color gradients, and star formation rates, which are generally lower than those in higher surface brightness galaxies.

## Contribution

It provides new observational data on the properties of intermediate surface brightness galaxies, highlighting differences in star formation and gas content compared to high surface brightness counterparts.

## Key findings

- Lower average star formation rates than high surface brightness galaxies
- Higher gas mass-to-luminosity ratios in studied galaxies
- Presence of diffuse Halpha emission indicating widespread star formation

## Abstract

We present B, R, and Halpha imaging data of 19 large disk galaxies whose properties are intermediate between classical low surface brightness galaxies and ordinary high surface brightness galaxies. We use data taken from the Lowell 1.8m Perkins telescope to determine the galaxies' overall morphology, color, and star formation properties. Morphologically, the galaxies range from Sb through Irr and include galaxies with and without nuclear bars. The colors of the galaxies vary from B-R = 0.3 - 1.9, and most show at least a slight bluing of the colors with increasing radius. The Halpha images of these galaxies show an average star formation rate lower than is found for similar samples with higher surface brightness disks. Additionally, the galaxies studied have both higher gas mass-to-luminosity and diffuse Halpha emission than is found in higher surface brightness samples.