Speaker
Description
Diffuse ionized gas (DIG) is an important component of the interstellar medium that is strongly connected to both star formation and feedback. The primary ionization mechanism of DIG is thought to be hard radiation from midplane OB stars. However, the emission spectrum of DIG shows features (such as enhanced [OIII] line emission) that models including only photoionization by midplane OB stars are incapable of reproducing. In a sample of eight nearby low-mass edge-on disk galaxies observed with the MUSE integral field spectrograph, we found that the extraplanar DIG in the galaxy with the lowest star-forming-rate (SFR) in the sample (ESO 544-27) had significant contribution to its ionization from radiation from hot low-mass evolved stars (HOLMES; up to 20 percent). This suggests that HOLMES ionization of DIG may be inversely proportional to the host galaxy SFR. Here I present a new project expanding this study to four additional low-SFR galaxies, with the goal of constraining the relationship between DIG ionization by HOLMES and host galaxy SFR.