Venters, ToniaToniaVentersAjello, MarcoMarcoAjelloBrandt, Terri J.Terri J.BrandtBlumer, HarshaHarshaBlumerBriggs, MichaelMichaelBriggsCoppi, PaoloPaoloCoppiD'AMMANDO, FILIPPOFILIPPOD'AMMANDOFields, BrianBrianFieldsFinke, JustinJustinFinkeFryer, ChrisChrisFryerHamaguchi, KenjiKenjiHamaguchiHarding, J. PatrickJ. PatrickHardingHewitt, John W.John W.HewittHumensky, BrianBrianHumenskyHunter, Stanley D.Stanley D.HunterLI, HUIHUILILongo, FrancescoFrancescoLongoMarcowith, AlexandreAlexandreMarcowithMcEnery, JulieJulieMcEneryOjha, RoopeshRoopeshOjhaPavlidou, VasilikiVasilikiPavlidouPetropoulou, MariaMariaPetropoulouPrescod-Weinstein, ChandaChandaPrescod-WeinsteinRani, BinduBinduRaniSantander, MarcosMarcosSantanderTomsick, John A.John A.TomsickWadiasingh, ZorawarZorawarWadiasinghWalter, RolandRolandWalter2020-12-302020-12-3020192330-9458http://hdl.handle.net/20.500.12386/29322This white paper is the first of a two-part series highlighting the most well-known high-energy cosmic accelerators and contributions that MeV gamma- ray astronomy will bring to understanding their energetic particle phenomena. This white paper discusses active galactic nuclei and gamma-ray bursts.ELETTRONICOenArticlehttps://baas.aas.org/pub/2020n3i485/release/12019BAAS...51c.485VFIS/05 - ASTRONOMIA E ASTROFISICAERC sectors::Physical Sciences and Engineering::PE9 Universe sciences: astro-physics/chemistry/biology; solar systems; stellar, galactic and extragalactic astronomy, planetary systems, cosmology, space science, instrumentation