Dwarf Galaxy Integral Survey (DGIS): 3-D mapping of dwarf galaxies in the local Volume

Existing optical integral surveys, such as MaNGA and SAMI etc, have made significant progress in various aspects of galaxy formation and evolution. comprehensive understanding of hierarchical structure formation requires detailed studies of low-mass galaxies. In this talk, we present the Dwarf Galaxy Integral Survey (DGIS) contains a representative sample of 65 dwarf galaxies (<1e9 solar mass) selected in the local volume (<11 Mpc) observed with MUSE/VLT and WiFes/ANU-2.3m in the past few years. With the high signal-to-noise ratio and a spatial resolution of down to 10-100 pc, the survey enables us to probe the inner profile of the dark matter through gaseous/stellar kinematics, searching for active galactic nuclei and their possible feedback, as well as investigating galactic scaling law at the low mass end. Here we highlight our recent results to study the 2-D distribution of metals in these dwarfs using two-point correlation functions. Compared to more massive spiral galaxies, metals in dwarfs are clustered on much smaller spatial scales and are homogenous over larger scales. By comparing the correlation length to SFR and stellar mass, we found that star formation, instead of stellar mass, plays the key role in regulating metal distribution in dwarfs, in contrast to the expectation from the tight correlation between metals and stellar masses of integrated galaxies.