Modulation of circumstellar extinction in a young binary system with a low-mass companion in a noncoplanar orbit

Abstract

The cyclic activity model of a young star with the low-mass secondary component (q = M2/M1 ≤ 0.1) accreting a matter from circumbinary disk is considered. It is assumed that the orbit is circular and the disk and orbital planes are non-coplanar. Sets of hydrodynamics models of such a system have been calculated by the SPH method and then the variations of the circumstellar extinction and phase light curves were determined. The calculations showed that depending on the model parameters and orientation of the system in regards to an observer the different in shape and amplitude light curves can be observed. An important property of the considered models is also the dependence of the mass accretion rate onto the components on the phase of the orbital period. The results of the calculation can be used for analysis of the cyclic activity of UX Ori stars and young stars with the long-lasting eclipses.

Reverse rotation of the accretion disk in RW Aur A: Observations and a physical model

“…The flow of matter in binary systems accreting material from protoplanetary disks has been simulated numerically in many studies [7][8][9][10][11][12][13][14][15][16][17]. The simulation results indicate the following major flow elements in these systems: circumstellar accretion disks around the system components, a rarefied area in the central parts of the protoplanetary disk adjoining the binary, and a complex system of gas-dynamical flows.…”

“…For reverse rotation to occur, the angular momentum delivered to the disk by the falling matter must be opposite to the angular momentum of the system. Numerical simulations of these systems have been performed in various studies [7][8][9][10][11][12][13][14][15][16][17], have not indicated the appearance of reversed accretion disks in binary systems for a wide range of parameters. In addition, analysis of the flow structure that forms in the vicinity of a young binary indicates that flows directed opposite to the motion of the components can exist [15].…”

Hydrodynamics of Young Binaries with Low-Mass Secondaries

“…These authors showed that the column density of matter along the line of sight can be a complicated function of the phase of the orbital period. Similar calculations have been continued in our subsequent papers (Demidova et al 522 T. , Grinin et al 2010a. We considered two types of binary orbits.…”

Bow shocks in disks of young binary systems

“…Calculations using the model based on the smoothed-particle hydrodynamics method (SPH) show that the lowmass component is the main accretor in the system [8][9][10][11][12], while the model based on the total variation diminishing (TVD) scheme gives an opposite result (see Refs. [13,14]).…”