scholarly journals Gravitational Waves Produced by Ejection of Jet Superluminal Components, Precession and Gravito-Magnetic Distortion of Accretion Disks in Active Galactic Nuclei, Micro-Quasars, and T-Tauri Stars Dynamically Driven by Bardeen-Petterson Effect

2011 ◽  
Vol 4 (1) ◽  
pp. 98-107
Author(s):  
Herman J. Mosquera Cuesta
2015 ◽  
Vol 2015 ◽  
pp. 1-5
Author(s):  
David Garofalo

While the basic laws of physics seem time-reversal invariant, our understanding of the apparent irreversibility of the macroscopic world is well grounded in the notion of entropy. Because astrophysics deals with the largest structures in the Universe, one expects evidence there for the most pronounced entropic arrow of time. However, in recent theoretical astrophysics work it appears possible to identify constructs with time-reversal symmetry, which is puzzling in the large-scale realm especially because it involves the engines of powerful outflows in active galactic nuclei which deal with macroscopic constituents such as accretion disks, magnetic fields, and black holes. Nonetheless, the underlying theoretical structure from which this accreting black hole framework emerges displays a time-symmetric harmonic behavior, a feature reminiscent of basic and simple laws of physics. While we may expect such behavior for classical black holes due to their simplicity, manifestations of such symmetry on the scale of galaxies, instead, surprise. In fact, we identify a parallel between the astrophysical tug-of-war between accretion disks and jets in this model and the time symmetry-breaking of a simple overdamped harmonic oscillator. The validity of these theoretical ideas in combination with this unexpected parallel suggests that black holes are more influential in astrophysics than currently recognized and that black hole astrophysics is a more fundamental discipline.


Astrophysics ◽  
2016 ◽  
Vol 59 (4) ◽  
pp. 439-448 ◽  
Author(s):  
M. Yu. Piotrovich ◽  
S. D. Buliga ◽  
Yu. N. Gnedin ◽  
A. G. Mikhailov ◽  
T. M. Natsvlishvili

1989 ◽  
Vol 341 ◽  
pp. 340 ◽  
Author(s):  
Gibor Basri ◽  
Claude Bertout

1990 ◽  
Vol 137 ◽  
pp. 209-213
Author(s):  
I. Appenzeller

T Tauri stars and flare stars are both magnetically active late-type stars of low mass and low to moderate luminosities. The flares observed in these two classes of variables show similar properties and, thus, probably have the same physical origin. On the other hand, at least the majority of the classical T Tauri stars seem to be surrounded by cool, dusty (accretion) disks, which are absent or undetectable in most classical flare stars.


2000 ◽  
Vol 195 ◽  
pp. 133-134
Author(s):  
P. C. H. Martens

Fletcher & Martens have successfully modeled solar hard X-ray sources observed at the top and footpoints of flaring magnetic loops with a Fokker-Planck type particle transport code. I show here that there are invariances in the Fokker-Planck equations that make these results applicable to environments with vastly different physical parameters, such as hard X-ray flares in accretion disks in active galactic nuclei, and in RS CVn and ALGOL type binaries.


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