Astronomy, space & time BL lacertae objects OJ 287 Physics Research & information: general Seyfert 1 objects: individual: Mrk 335 X-Rays:binaries-stars individual: (XTE J1908+094)-stars:black holes-accretion X-rays X-rays: binaries-stars individual: (V404 Cygni)-stars:black holes-accretion accretion discs accretion disks-shock waves-radiation:dynamics accretion of matter active active galactic nuclei black hole evolution black hole physics black string blazars broad line region galaxies galaxies-quasars galaxies: active galaxies: evolution galaxies: jets galaxies: nuclei geodesic orbits gravitational waves individual (Ton 599) inverse-Compton emission ionized gas