In 1990, Alain Omont became director of the IAP. He maintained previous research topics with a particular focus on cosmology, extragalactic astrophysics and data analysis. The IAP became a truly dynamic international laboratory: in 1991, the institute was granted the status of “European Laboratory” and international collaborations multiplied, with very active visitor-friendly policies. The educational contributions became even more important when the IAP hosted the DEA program of the Paris 6 University. At that time, the IAP started to play the role of an attraction center in astrophysics within the city of Paris, being particularly open to the scientific events of the national and international communities. The IAP created the status of “associate researcher” which facilitates the collaboration of scientists from other institutes with members of the IAP, after co-optation by the institute scientific council. A large part of that research dynamic is a consequence of the IAP opening up to interdisciplinary and international exchange.

In 1998, Bernard Fort took over as head of the IAP, which at the time still had the status of CNRS laboratory. The teams split into four research groups (Cosmology, Structures and Galaxies; Cosmology and Nucleosynthesis; Magnetism and Transfer; Interstellar and Planetary Media, Compact Objects). The analysis of massive amounts of data, and the required numerical simulations to interpret them, were boosted with the creation of a technical platform called “POLARIS” (POLe Astrophysique de Recherche en traitement de l’Information et Simulation Numérique –“Astrophysical Hub for Research in Data Analysis and Numerical Simulation”). This project was endorsed and supported by the Ile-de-France region.