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Evidence For Binary Orbital Motion Of A Quasar Broad-Line Region, C. Martin Gaskell

C. Martin Gaskell Publications

Analysis of spectra of the quasar 3C 390.3 covering a period of over 20 yr shows that the blueshifted peak of H beta has been changing its radial velocity at an almost constant rate during this time. The radial velocity has increased by over 1500 km/s. The lower limit to the period of radial velocity changes is 210 yr. Although very long periods cannot be excluded by the radial velocity curve alone, other considerations suggest that the period is about 300 yr. If the radial velocity changes are due to orbital motion, the radius of the orbit is about 0.3 …