Star Formation Rate in late-type galaxies: I- The H(alpha) and FUV integrated values

TL;DR

This study compares star formation rates in late-type galaxies using H(alpha) and FUV fluxes, revealing differences based on galaxy type and the influence of diffuse ionized gas on measurements.

Contribution

It provides a comparative analysis of SFR indicators in late-type galaxies and examines the spatial distribution and ionization sources affecting star formation measurements.

Findings

FUV-based SFR generally exceeds H(alpha)-based SFR

Sm galaxies exhibit higher SFR than other late types

Diffuse ionized gas impacts SFR estimates if leaking photons are involved

Abstract

The Star Formation Rate (SFR) was determined from a sample of 36 late-type galaxies (14 dS and 22 Sm), from the H(alpha) and Far Ultraviolet (FUV) flux. We found that the SFR(FUV) was in most cases higher than the SFR(H(alpha)).We also obtained that the SFR is larger for Sm galaxies and smaller for barred galaxies, for any morphological type, in both diagnostic methods. In addition, a study of the spatial distribution of star formation within these galaxies was made, concluding that there is not a preferential place for the star formation. Finally, we studied the role of the Diffuse Ionized Gas in the SFR value, finding that the H(alpha) flux contribution coming from this gas should not be included in the SFR determination unless it is verified that leaking photons are the only source of the neutral gas ionization.