Oral Presentation

The Metallicity of DESI Dwarf Galaxies

Author(s): Yu Voon Ng (NTU); Ting-Wen Lan (NTU)

Presenter: Yu Voon Ng (National Taiwan University)

The mass-metallicity relation indicates that galaxies with higher stellar masses tend to have higher metallicities. However, the low-mass end of this relationship remains poorly understood due to the difficulties of identifying dwarf galaxies and measuring their metallicities. In this talk, I will present the latest results of exploring the low-mass end of the relation using the new dataset from the Dark Energy Spectroscopic Instrument (DESI) survey at redshifts within 0.1. We employ a convolutional neural network (CNN) method to identify the dwarf candidates from the images and then estimate the gas metallicity of galaxies with multiple lines detected in the DESI spectra. For systems with limited line information, we explore a new parameter space and stack the spectra to obtain their metallicities. Utilizing the DESI dataset, we largely increase the sample size and obtain stringent constraints on the mass-metallicity relation at the low-mass end.