WALLABY Pilot Survey: A gas-rich diffuse dwarf on the baryonic Tully Fisher relation

Abstract: Diffuse dwarf galaxies, and particularly ultra diffuse galaxies (UDGs), challenge our understanding of galaxy formation and the role of dark matter due to their large sizes, low surface brightness, and varying dark matter content. In this work, we investigate the gas-rich diffuse dwarf galaxy WALLABY J125956-192430 (aka. KK176) using high-resolution HI data from the WALLABY survey. We produce the most reliable kinematic model for KK176 to date. Using this model, the derived mass decomposition shows that KK176 is dark matter dominated. We also place KK176 on the baryonic Tully-Fisher relation (bTFR), finding that it is consistent with low-mass dwarf galaxies but distinctly different from reported dark matter-deficient UDGs.