Implosive accretion and outbursts of active galactic nuclei

Abstract

view Abstract Citations (106) References (54) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Implosive Accretion and Outbursts of Active Galactic Nuclei Lovelace, R. V. E. ; Romanova, M. M. ; Newman, W. I. Abstract A model and simulation code have been developed for time-dependent axisymmetric disk accretion onto a compact object including for the first time the influence of an ordered magnetic field. The accretion rate and radiative luminosity of the disk are naturally coupled to the rate of outflow of energy and angular momentum in magnetically driven (+/-z) winds. The magnetic field of the wind is treated in a phenomenological way suggested by self-consistent wind solutions. The radial accretion speed u(r,t) of the disk matter is shown to be the sum of the usual viscous contribution and a magnetic contribution is proportional to r^3/2^B_p_^2^/σ, where B_p_(r, t) is the poloidal field threading the disk and σ(r, t) is the disk's surface mass density. An enhancement or variation in B_p_ at a large radial distance leads to the formation of a soliton-like structure in the disk density, temperature, and B-field which propagates implosively inward. The implosion gives a burst in the power output in winds or jets and a simultaneous burst in the disk radiation. The model is pertinent to the formation of discrete fast-moving components in jets observed by very long baseline interferometry. These components appear to originate at times of optical outbursts of the active galactic nucleus. Publication: The Astrophysical Journal Pub Date: December 1994 DOI: 10.1086/174981 Bibcode: 1994ApJ...437..136L Keywords: Accretion Disks; Active Galactic Nuclei; Astronomical Models; Interstellar Magnetic Fields; Plasma Jets; Stellar Winds; Computerized Simulation; Mathematical Models; Astrophysics; GALAXIES: ACTIVE; ACCRETION; ACCRETION DISKS; GALAXIES: JETS; GALAXIES: NUCLEI full text sources ADS | data products SIMBAD (2)