The Effects of Diffuse Ionized Gas and Spatial Resolution on Metallicity Gradients

• Main Authors: Poetrodjojo, Henry, None
• Format: Conference Object
• Language: unknown
• Published: Zenodo 2019
• Subjects: sami
• Online Access: https://dx.doi.org/10.5281/zenodo.2635385; https://zenodo.org/record/2635385

The gas-phase metallicity of a galaxy is strongly affected by the processes that occur during the galaxy's evolution. Gas inflows, galaxy mergers and galactic winds are a few examples of events that alter the spatial metallicity distribution. Measuring the metallicity of a galaxy therefore leads to strong constraints on its growth and formation. With the recent emergence of large IFU galaxy surveys such as CALIFA, SAMI and MaNGA, we can begin to probe the metallicity distribution of galaxies and disentangle degeneracies using large datasets. However, contamination by the diffuse ionized gas significantly affects metallicity measurements. At the low spatial resolution scales of these large IFU surveys, HII regions can not be separated from the diffuse ionized gas, leading to systematic errors in these measurements. We use high spatial resolution data from the TYPHOON survey to separate the HII regions and the diffuse ionized gas to understand the effects of spatial resolution and diffuse ionized gas contamination on measured metallicity gradients. We find that at resolutions exceeding 1 kiloparsec, the spatial resolution of several large IFU surveys, it is impossible to retrieve the true metallicity gradient due to DIG contamination.