INVESTIGATION OF RADIATIVE OUTFLOWS AROUND COMPACT OBJECTS

2000 ◽  
Vol 09 (01) ◽  
pp. 57-69 ◽  
Author(s):  
INDRANIL CHATTOPADHYAY ◽  
SANDIP K. CHAKRABARTI

Winds and outflows form in active galaxies and in binary systems which are known to harbour compact objects such as black holes. Matter starting subsonically from a disc must be accelerated very close to the black hole in order to reach a velocity comparable to the velocity of light, which is actually observed. In the absence of magnetic fields, winds forming in inner regions of accretion discs could primarily be accelerated by radiations emitted from this region where centrifugal force is important. We study critical point behaviour of outflows in presence of this radiative acceleration. We show that the momentum deposition term changes the character of the solution drastically depending on the magnitude and the location of the deposition. We discuss the implications of these solutions in detail. Particularly important is the fact that matter were found to be pushed to infinity, even when they were originally bound energetically. We perform numerical simulations by smoothed particle hydrodynamics (SPH), and show that these new solutions are stable.

2007 ◽  
Vol 3 (S246) ◽  
pp. 271-272
Author(s):  
C.-P. Lajoie ◽  
A. Sills

AbstractWe present preliminary work on the formation scenario of blue straggler stars by mass transfer in binary systems. More precisely, using Smoothed Particle Hydrodynamics (SPH), we want to model only the outer parts of the stars in order to get a much greater spatial resolution of the mass transfer flow itself. The inner boundary conditions are achieved using the so-called ghost particles and by replacing the inner mass by a central point mass. Stability of this central point mass is crucial, and it is shown that we get reasonable results. These simulations should give us indications on which layers of the donor star are actually transferred to the other star as well as how mass is transferred and how it settles on the accretor. This work is aimed at getting distinct observational signatures which would help identifying the dominant formation mechanism of blue straggler stars.


1993 ◽  
Vol 404 ◽  
pp. 678 ◽  
Author(s):  
Pablo Laguna ◽  
Warner A. Miller ◽  
Wojciech H. Zurek

Proceedings ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 1 ◽  
Author(s):  
Enrico Barausse

The recent detections of gravitational waves from binary systems of black holes are in remarkable agreement with the predictions of General Relativity. In this pedagogical mini-review, I go through the physics of the different phases of the evolution of black hole binary systems, providing a qualitative physical interpretation of each one of them. I also briefly describe how these phases would be modified if gravitation were described by a theory extending or deforming General Relativity, or if the binary components turned out to be more exotic compact objects than black holes.


Sign in / Sign up

Export Citation Format

Share Document