Related papers: Accretion disks around massive stars: Hydrodynamic…
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…
In this note we study the accretion disc that arises in hypercritical accretion of $\dot M\sim 10^8 M_{\rm Edd}$ onto a neutron star while it is in common envelope evolution with a massive companion. In order to raise the temperature high…
Cosmic metallicity evolution possibly creates the diversity of star formation modes at different epochs. Gravitational fragmentation of circumstellar discs provides an important formation channel of multiple star systems, including close…
Proto-planetary discs, the birth environment of planets, are an example of a structure commonly found in astrophysics, accretion discs. Identifying the mechanism responsible for accretion is a long-standing problem, dating back several…
We present a study of the evolution of the inner few astronomical units of protoplanetary disks around low-mass stars. We consider nearby stellar groups with ages spanning from 1 to 11 Myr, distributed into four age bins. Combining…
We have studied dust evolution in a quiescent or turbulent protoplanetary disk by numerically solving coagulation equation for settling dust particles, using the minimum mass solar nebular model. As a result, if we assume an ideally…
We study dust accumulation by photophoresis in optically thin gas disks. Using formulae of the photophoretic force that are applicable for the free molecular regime and for the slip-flow regime, we calculate dust accumulation distances as a…
A star forms when a cloud of dust and gas collapses. It is generally believed that this collapse first produces a flattened rotating disk, through which matter is fed onto the embryonic star at the center of the disk. When the temperature…
The collapse of dense cores with different metallicities is studied by hydrodynamical calculations coupled with detailed chemical and radiative processes. For this purpose, we construct a simple chemical network with non-equilibrium…
We investigate the structure and stability of hypercritical accretion flows around stellar-mass black holes, taking into account neutrino cooling, lepton conservation, and firstly a realistic equation of state in order to properly treat the…
Observations indicate that massive stars form in regions of very high surface density, ~1 g cm^-2. Clusters containing massive stars and globular clusters have a comparable column density. The total pressure in clouds of such a column…
Protoplanetary disks are often assumed to change slowly and smoothly during planet formation. Here, we investigate the time evolution of isolated disks subject to viscosity and a disk wind. The viscosity is assumed to increase rapidly at…
In the disk-mediated accretion scenario for the formation of the most massive stars, gravitational instabilities in the disk can force it to fragment. We investigate the effects of inclination and spatial resolution on observable kinematics…
The formation of planets strongly depends on the total amount as well as on the spatial distribution of solids in protoplanetary disks. Thanks to the improvements in resolution and sensitivity provided by ALMA, measurements of the surface…
Dust constitutes only about one percent of the mass of circumstellar disks, yet it is of crucial importance for the modeling of planet formation, disk chemistry, radiative transfer and observations. The initial growth of dust from…
By taking into account the local energy balance per unit volume between the viscous heating and the advective cooling plus the radiative cooling, we investigate the vertical structure of radiation pressure-supported accretion disks in…
We present detailed models of irradiated T Tauri disks including dust grain growth with power-law size distributions. The models assume complete mixing between dust and gas and solve for the vertical disk structure…
Dust determines the temperature structure of protoplanetary disks. However, dust temperature determinations almost invariably rely on a complex modeling of the Spectral Energy Distribution. We attempt a direct determination of the…
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…
Protoplanetary disks are mainly heated by radiation from the central star. Since the incident stellar flux at any radius is sensitive to the disk structure near that location, an unstable feedback may be present. Previous investigations…