title: Carbonaceous grain processing in space and in the laboratory.
abstract: Laboratory simulations of carbonaceous grain processing which occurs in space are fundamental to outline an evolutionary pathway for these particles. We consider the UV spectral changes induced in hydrogenated carbon grains by thermal annealing, UV irradiation and ion bombardment. The results give the opportunity to interpret observations in different space environments. In particular, modelling of the optical properties, based on a description of the electronic structure of carbons, indicates small hydrogenated amorphous carbon grains, with different degrees of UV irradiation, as the carrier of the ubiquitous UV interstellar extinction bump.
authors.affiliation: Osservatorio Astronomico di Capodimonte, Napoli, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Mennella
authors.forename: L
authors.initials: L
authors.lastname: Colangeli
authors.forename: J R
authors.initials: JR
authors.lastname: Brucato
authors.forename: E
authors.initials: E
authors.lastname: Epifani
authors.forename: E
authors.initials: E
authors.lastname: Palomba
authors.forename: P
authors.initials: P
authors.lastname: Palumbo
authors.forename: A
authors.initials: A
authors.lastname: Rotundi
mesh_terms: D002244:Carbon / Q000737:chemistry* / Q000528:radiation effects; D019443:Cosmic Dust; D003359:Cosmic Radiation; D018559:Exobiology; D005118:Extraterrestrial Environment; D006358:Hot Temperature; D008956:Models, Chemical; D010777:Photochemistry; D013056:Spectrophotometry, Ultraviolet; D014466:Ultraviolet Rays
chemical_list: D019443:Cosmic Dust; D002244:Carbon