Galaxy evolution is driven by a complex combination of internal (nature) and external (nurture) processes. Gas stripping due to ram pressure arises as a galaxy falls into the dense intracluster medium of a galaxy cluster, and is among the most violent environmental experiences a galaxy can have. The most spectacular examples of ram-pressure stripping in action are the so-called "jellyfish galaxies", which display extended tails of optically bright stripped material. I will review several theoretical and observational studies that aim to characterize the effect of gas stripping in galaxy evolution, including the latest results of the large MUSE program GASP, dedicated to studying jellyfish galaxies. Finally, I will, present the recent discovery of a previously unknown connection between ram-pressure stripping and nuclear black hole activity.
One of the biggest challenges in modern cosmology is to understand the first generation of stars and galaxies that formed during the cosmic Dark Ages. Since they reside in the observationally unexplored territory, we need to predict the properties of the first galaxies by pushing numerical simulations to new levels of physical realism and detail. In this talk, I will present the results of our highly-resolved cosmological ab-initio simulations to understand the assembly process of first galaxies under the feedback from the first generation of stars, the so-called Population III. Also, I will illustrate how first galaxies can be connected with their local descendants in terms of chemical abundances in the local ultra-faint dwarf galaxies.
The recent discoveries of gravitational waves from the advanced LIGO have already been critical cosmological resources. Here, I will present cosmological implications of gravitational wave detection, and show how current and future gravitational observatories can advance our knowledge on the nature of dark matter and dark energy.