Expositora: Mar Carretero-Castrillo, UB
High-energy gamma-ray astrophysics focuses on the study of the most extreme accelerators in the Universe. An example of these accelerators are gamma-ray binaries. These systems are composed of a massive O or Be-type star and a compact object, emitting gamma rays up to multi-TeV energies. Because only a handful of them are known and some of their properties are not fully understood, the discovery of new gamma-ray binaries may help to answer many open questions through population studies, though it may eventually open new ones. Given that the known gamma-ray binaries containing O-type stars are runaways, we search for runaway stars within catalogs of massive stars using Gaia DR3 astrometric data. We present here the current status of our project, with tens of new runaway O and Be stars identified, together with multi-wavelength information. The search for non-thermal emission using multi-wavelength data, together with radial velocity studies to confirm their binary nature, will help us build a list of potential gamma-ray binaries. The future Cherenkov Telescope Array (CTA) will play a crucial role in unveiling their nature as gamma-ray sources, thus allowing to enlarge the population for future studies.