연사: Dr. Ryan Jackson (University Of Hertfordshire)

일시: 2021년 12월 3일 금요일 11:00

장소: 온라인

Abstract:

Low-surface-brightness galaxies (LSBGs) — defined as systems that are fainter than the surface-brightness limits of past wide-area surveys — form the overwhelming majority of galaxies in the dwarf regime (M* < 10^9 MSun). It is therefore vital to understand how these galaxies form if we are to truly understand galaxy evolution. Using the Horizon-AGN and NewHorizon simulations, we study the origin of LSBGs and explain why LSBGs at similar stellar mass show the large observed spread in surface brightness. We also show that observed dwarf galaxies in current wide-area surveys are likely an anomalous population of dwarf galaxies with high SFRs. Therefore, they should not be used to represent the total dwarf galaxy population. Within this large LSBG population, there are also interesting subsets of galaxies to be studied. One such population are dark-matter-deficient galaxies, whose existence potentially challenges the current LCDM paradigm. We show how these galaxies can form within the NewHorizon simulation and are therefore not a threat to our cosmological models.