DE ROSA, AlessandraAlessandraDE ROSABianchi, S.S.BianchiBogdanovic, T.T.BogdanovicDECARLI, ROBERTOROBERTODECARLIHeidt, J.J.Heidtherrero-illana, r.r.herrero-illanaHusemann, B.B.HusemannKomossa, S.S.KomossaKun, E.E.KunLoiseau, N.N.LoiseauGuainazzi, M.M.GuainazziParagi, Z.Z.ParagiPerez-Torres, M.M.Perez-TorresPiconcelli, E.E.PiconcelliSchawinski, K.K.SchawinskiVignali, C.C.Vignali2021-02-082021-02-0820170004-6337http://hdl.handle.net/20.500.12386/30230In this paper we present an overview of the MAGNA (Multiple AGN Activity) project aiming at a comprehensive study of multiple super-massive black hole systems. With the main goal of characterizing the sources in merging systems at different stages of evolution, we selected a sample of objects optically classified as multiple systems on the basis of emission line diagnostics and started a massive multiband observational campaign. Here we report on the discovery of the exceptionally high active galactic nuclei (AGN) density compact group SDSS (Sloan Digital Sky Survey) J0959+1259. A multiband study suggests that strong interactions are taking place among its galaxies through tidal forces, and therefore this system represents a case study for physical mechanisms that trigger nuclear activity and star formation. We also present a preliminary analysis of the multiple AGN system SDSS J1038+3921.STAMPAenArticle10.1002/asna.2017133402-s2.0-85015987935000400339900021https://onlinelibrary.wiley.com/doi/abs/10.1002/asna.2017133402017AN....338..262DFIS/05 - ASTRONOMIA E ASTROFISICA