Coffee/tea and cookies will be served in the coffee lounge of 52HLH starting at 2 PM. Bring your own mug if you have!
Observing and understanding the surface mass density – metallicity relation via the SDSS IV MaNGA survey
I will present the latest results on the resolved stellar mass - metallicity relation ( i.e., stellar surface mass density vs. gas metallicity) for more than 500,000 spatially-resolved star-forming resolution elements (spaxels) from a sample of 653 disk galaxies included in the SDSS IV MaNGA survey. We find a tight relation between these local properties, with higher metallicities as the surface density increases. This relation extends over three orders of magnitude in the surface mass density and a factor of four in metallicity. We show that this local relationship can simultaneously reproduce two well-known properties of disk galaxies: their global mass-metallicity relationship and their radial metallicity gradients. We also find that this relation is largely independent of the galaxy’s total stellar mass and specific star-formation rate (sSFR), except at low stellar mass and high sSFR, suggesting that in the present-day universe local properties play a key role in determining the gas-phase metallicity in typical disk galaxies. I will also introduce a simple yet illustrative semi-analytical leaked-box model aimed to explain this local relation as well as the localized star formation history and chemical evolution in disk galaxies.