Resolving the Formation of Cold H i Filaments in the High-velocity Cloud Complex C

The physical properties of galactic halo gas have a profound impact on the life cycle galaxies. As travels through halo, it undergoes dynamical interactions, influencing its star formation and chemical evolution disk. In Milky Way considerable effort has been made to understand spatial distribution neutral gas, which is mostly in form large complexes. However, internal variations their remain unclear. this study, we investigate thermal state high-velocity clouds. High-resolution observations (11) 21 cm line emission EN field DHIGLS H i survey are used analyze bright concentration CIB located at an edge HVC complex, complex C. We use Gaussian decomposition code ROHSA model multiphase content perform power spectrum analysis multiscale structure. some 200 structures extracted using dendrograms examined. Each phase exhibits different turbulent properties. identify two distinct regions, one prominent protrusion extending from C that ongoing transition warm diffuse cold dense filaments. scale becomes unstable condensation about 15 pc, corresponding cooling time 1.5 Myr. Our study characterizes statistical turbulence fluid for first time. find subsonic transonic associated with condensation, going small scales. A large-scale perspective suggests hydrodynamic instabilities involved creating structured therein. details processes unclear will require further investigation both numerical simulations.