Exploring the universe from deep underground to deep seas and high altitudes

My research activity is tightly related to astrophysics. Starting from diploma and PhD thesis and following post-docs and permanent positions, I always worked in experiments devoted to the understanding of the mechanisms occurring in stars from the early and quiescent evolutionary stages to the final explosive ones leading to the extreme energetic scenarios that characterize the most violent Universe such as black holes and neutron stars. During my career I have mainly participated to three experiments which I will present in the following: - LUNA is an experiment which measures nuclear reaction rates that are occurring in stars. It is located deep underground in the Gran Sasso National Laboratory in Italy. Thanks to the low cosmic background LUNA has been able to measure cross sections at energies very close to the energy region at which they take place in stars. I have worked in LUNA from 1999 to 2010, participating to the construction of the facility and to the main reaction rate measurements. The experiment, the motivation and a major measurement performed at LUNA is presented in chapter 1. - ANTARES is a neutrino telescope located in the Mediterranean sea constructed to detect neutrinos coming from the most extreme sources in the Universe. I have joined ANTARES in 2007 and have been deeply involved in the simulation of the detector and in particular in its calibration. I also performed a feasibility study to determine the sensitivity of the telescope to detect neutrinos from a supernova explosion. The experiment, the calibration activity and the sensitivity study of supernova neutrinos is presented in chapter 2. - CTA is the next generation high energy gamma-ray observatory. I joined CTA in 2010 and it has become my principle activity since 2014. I have been mainly involved in the simulation of the telescopes and recently in the sensitivity studies for the detection of PeV galactic cosmic rays sources known as PeVatrons. The CTA observatory, together with simulation of the telescopes and the work on the search for PeVatron sources is presented in chapter 3. In chapter 4 I summarize the scientific challenges I have faced during my research career in the context of the past and present scientific panorama and I present the perspectives for the next years. In Appendix A an extended Curriculum Vitae is presented. (author)