Can star collisions explain the AGN variability ?
نویسنده
چکیده
Star collisions may easily occur in a cluster of stars orbiting around a massive black hole. Such collisions can transform part of the star kinetic energy in observable radiating energy. In this paper we derive the star collision rate and the resulting highly variable luminosity for the case of a cluster containing stars of different masses. The variability of the derived light curves is computed for different sets of parameters and compared to the available data (Paltani & Courvoisier 1997). The comparison shows that the observed data trend can be reproduced by this model.
منابع مشابه
AGN Zoo and Classications of Active Galaxies
We review the variety of Active Galactic Nuclei (AGN) classes (so-calledAGN zoo") and classification schemes of galaxies by activity types based on their optical emission-line spectrum, as well as other parameters and other than optical wave-length ranges. A historical overview of discoveries of various types of active galaxies is given, including Seyfert galaxies, radio galaxies, QSOs, BL Lace...
متن کاملI. A star orbiting around a supermassive rotating black hole: Free motion and corrections due to star-disc collisions
Our aim is to study the evolution of the orbit of a star under the influence of interactions with an accretion disc in an AGN. The model considered consists of a low-mass compact object orbiting a supermassive black hole and colliding periodically with the accretion disc. Approximate calculations based mostly on Newtonian theory of gravity have been carried out by several authors to estimate th...
متن کاملGlobal Star Formation Revisited
A general treatment of disk star formation is developed from a dissipative multi-phase model, with the dominant dissipation due to cloud collisions. The Schmidt-Kennicutt law emerges naturally for star-forming disks and starbursts. We predict that there should be an inverse correlation between Tully-Fisher law and Schmidt-Kennicutt law residuals. The model is extended to include a multi-phase t...
متن کاملForced accretion in stochastically fed AGN and quasars
Steady state accretion discs larger than ∼ 0.01−0.1 pc are known to be gravitationally unstable for the accretion rates needed to explain super-massive black hole (SMBH) activity. We propose that SMBH are fed by a succession of mass deposition events with randomly directed angular momenta. Because of incomplete angular momentum cancellation a warped accretion disc forms in the inner few parsec....
متن کاملGiant Agn Flares and Cosmic Ray Bursts
We predict a new class of intense, short-duration AGN flares resulting from the tidal disruption of a star or from a disk instability, and show that the rate and power of these flares can readily explain the observed flux and distribution of the highest energy cosmic rays. We describe the photon bursts produced by such AGN flares and show that they may soon be detectable. Subject headings: cosm...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2000