Oral Presentation

Exploring the Evolution of SFR and Gas-Phase Metallicity in Spiral Galaxies Over the Past 3Gyr

Author(s): Qian-Hui Chen (The Australian National University)

Presenter: Qianhui Chen (The Australian National University)

Spiral structures are important drivers of the secular evolution of disc galaxies, however, the effects of spiral arms on the development of galaxies remain mysterious. In this talk, we present two spiral galaxies at z~0.3 from the Middle Age Galaxy Properties with Integral Field Spectroscopy (MAGPI) survey and nine nearby spiral galaxies from the TYPHOON survey. We investigate the two-dimensional distributions of star formation rate (Halpha) and gas-phase metallicity. We notice significant offsets in Halpha (~0.2 dex) among the spiral arms, downstream and upstream of SG1202 at z~0.3. No azimuthal variation in Halpha or gas-phase metallicities is observed in SG1204, another spiral galaxy at z~0.3, which can be attributed to the tighter spiral arms in SG1204 than SG1202, coming associated with stronger mixing effects in the disc. Expanding the study to nine nearby spiral galaxies with the TYPHOON survey, we observe that the azimuthal variation in SFR and metallicity in 3 of our galaxies. These findings suggest changing relationships between SFR and metallicity over the past 3 billion years. It also highlights the complex influence of spiral arms on metal mixing in galactic discs.