相关论文: Accretion Disc Evolution in Single and Binary T Ta…
We investigate the evolution of accretion luminosity $L_{\rm acc}$ and stellar luminosity ${L_\ast}$ in pre-mainsequence stars. We make the assumption that when the star appears as a Class II object, the major phase of accretion is long…
We present the results of non linear, hydrodynamic simulations, in three dimensions, of the tidal perturbation of accretion discs in binary systems where the orbit is circular and not necessarily coplanar with the disc mid-plane. The…
We construct detailed vertical structure models of irradiated accretion disks around T Tauri stars with interstellar medium dust uniformly mixed with gas. The dependence of the structure and emission properties on mass accretion rate,…
We show that the distribution of observed accretion rates is a powerful diagnostic of protoplanetary disc physics. Accretion due to turbulent ("viscous") transport of angular momentum results in a fundamentally different distribution of…
We consider the effects of stellar magnetic cycles on disc accretion in T Tauri stars where the inner region of the disc is disrupted by the stellar field. Using time-dependent disc models, we show that order unity variations in field…
We determine inner disk sizes and temperatures for four solar-type (1-2 M$_{\odot}$) classical T Tauri stars (AS 207A, V2508 Oph, AS 205A, and PX Vul) using 2.2 $\mu$m observations from the Keck Interferometer. Nearly contemporaneous…
We present a two-layer accretion disc model developed to simultaneously fit optical long baseline visibilities and spectral energy distributions of T Tauri accretion discs. Our model includes viscous heating and absorption of stellar…
We construct a new set of self-consistent analytical disk models by taking into account both viscous and radiative sources of thermal energy. We analyze the non-isothermal structure of the disk across the mid-plane for optically thick…
The structure of accretion discs around magnetic T Tauri stars is numerically calculated using a particle hydrodynamical code, in which magnetic interaction is included in the framework of King's diamagnetic blob accretion model. Setting up…
This paper reviews current theoretical work on the various stages of accretion in protostars, and the relationship of these ideal stages to the spectral classes of observed protostellar systems. I discuss scaling relationships that have…
The question whether the interaction of a circumbinary disc with the central binary system leads to shrinking or expansion of the binary orbit has attracted considerable interest as it impacts the evolution of binary black holes and stellar…
We use one-dimensional two-zone time-dependent accretion disk models to study the long-term evolution of protostellar disks subject to mass addition from the collapse of a rotating cloud core. Our model consists of a constant surface…
(Abridged) We explore the role of X-ray photoevaporation in the evolution and dispersal of viscously evolving T-Tauri discs. We show that the X-ray photoevaporation wind rates scale linearly with X-ray luminosity, such that the observed…
Classical T Tauri stars are pre-main-sequence objects that undergo simultaneous accretion, wind outflow, and coronal X-ray emission. The impact of plasma on the stellar surface from magnetospheric accretion streams is likely to be a…
Accretion onto Classical T Tauri stars is thought to take place through the action of magnetospheric processes, with gas in the inner disk being channeled onto the star's surface by the stellar magnetic field lines. Young stars are known to…
The unusual properties of transition objects (young stars with an optically thin inner disc surrounded by an optically thick outer disc) suggest that significant disc evolution has occured in these systems. We explore the nature of these…
Recent observations show a strong correlation between stellar mass and accretion rate in young stellar and sub-stellar objects, with the scaling $\dot{M}_{acc} \propto M_*^2$ holding over more than four orders of magnitude in accretion…
Given that a majority of stars form in multiple systems, in order to fully understand the star- and planet-formation processes we must seek to understand them in multiple stellar systems. With this in mind, we present an analysis of the…
We describe some recent nonlinear three dimensional hydrodynamic simulations of accretion discs in binary systems where the orbit is circular and not necessarily coplanar with the disc midplane. The calculations are relevant to a number of…
We show that discs accreting onto the magnetosphere of a rotating star can end up in a 'trapped' state, in which the inner edge of the disc stays near the corotation radius, even at low and varying accretion rates. The accretion in these…