Harold Linnartz holds the chair for Laboratory Astrophysics at Leiden Observatory and is the director of Laboratory for Astrophysics at UL. He heads the experimental activities under InterCat at Leiden University.

His group specializes in experimental studies in astrochemistry with emphasis on the spectroscopy of interstellar ices and the quantitative characterization of reactions on the surface and in the bulk of such ices. Under InterCat these techniques will be used to determine the impact of the nanoparticles studied at AU on reactions in ices under UV photo-processing and upon atom bombardment. He is co-PI of IceAge, a large JWST Early Release Science (ERS) program, fully dedicated to search for ices in the interstellar medium with a special focus on frozen complex organic molecules.