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Active nuclei of galaxies
Author(s) -
Dibay E. A.
Publication year - 1976
Publication title -
astronomische nachrichten
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.394
H-Index - 63
eISSN - 1521-3994
pISSN - 0004-6337
DOI - 10.1002/asna.19762970612
Subject(s) - physics , astrophysics , luminosity , kinetic energy , active galactic nucleus , galaxy , astronomy , classical mechanics
The parameters of fifteen active nuclei are determined from spectroscopic and photometric observations. The values of bolometric luminosity, gas volume and mass, kinetic energy, characteristic dimension and kinematic time‐scale are given. The fluxes of radiative and mechanical energy of the gas envelope are compared. A steady‐state model of the nucleus is proposed with the kinetic energy of the envelope being balanced by the light pressure. The life‐time of the nucleus appears to be of the same order of magnitude as the life‐time of the surrounding galaxy. The broad emission lines suggest to be caused by the gravitational potential of the nucleus. The masses of the central bodies are calculated on this basis. The typical central body mass of an active nucleus is about 10 8 solar masses. The mass‐luminosity relation is constructed. The steady‐state model seems to explain the optical variability process. Collaps to the center of separate gas clouds, as results of Rayleigh‐Taylor instability, leads to the flares, amplitudes and time‐scales being in agreement with observations.