Related papers: Non-isothermal effects on Be disks

Massive stars can during their evolution reach the phase of critical (or very rapid, near-critical) rotation when further increase in rotation rate is no longer kinematically allowed. The mass ejection and angular momentum outward transport…

We present a 3-D NLTE Monte Carlo radiative transfer code that we use to study the temperature and ionization structure of Keplerian disks around Classical Be stars. The method we employ is largely similiar to the Monte Carlo transition…

We model the IR Spectral Energy Distribution of circumstellar disks embedded in a HII region and photoevaporated by the external UV radiation. The model applies to the photoevaporated disks (proplyds) in Orion Nebula. First we calculate the…

We present millimeter imaging observations in the 1200 micron continuum of the disk around beta Pictoris. With the 25 arcsec beam, the beta Pic disk is unresolved perpendicularly to the disk plane (< 10 arcsec), but slightly resolved in the…

We examine the ``puffed-up inner disk'' model (Dullemond, Dominik & Natta 2001), proposed for explaining the near-IR excess radiation from Herbig Ae/Be stars. Detailed model computations show that the observed near-IR excess requires more…

We have computed radiative equilibrium models for the gas in the circumstellar envelope surrounding the hot, classical Be star $\gamma $Cassiopeia. This calculation is performed using a code that incorporates a number of improvements over…

In order to study the growth and evolution of circumstellar disks around classical Be stars, we analyze optical time-series photometry from the KELT survey with simultaneous infrared and visible spectroscopy from the APOGEE survey and BeSS…

Context. Classical Be stars are hot non-supergiant stars surrounded by a gaseous circumstellar disk that is responsible for the observed infrared-excess and emission lines. The phenomena involved in the disk formation still remain highly…

We discuss the properties of an accretion disk around a star with parameters typical of classical T Tauri stars (CTTS), and with the average accretion rate for these disks. The disk is assumed steady and geometrically thin. The turbulent…

We review advances in the modeling of protoplanetary disks. This review will focus on the regions of the disk beyond the dust sublimation radius, i.e. beyond 0.1 - 1 AU, depending on the stellar luminosity. We will be mostly concerned with…

Circumstellar disks are an essential ingredient of the formation of low-mass stars. It is unclear, however, whether the accretion-disk paradigm can also account for the formation of stars more massive than about 10 solar masses, in which…

The effect of gravitational darkening on models of the thermal structure of Be star disks is systematically studied for a wide range of Be star spectral types and rotation rates. Gravitational darkening causes a reduction of the stellar…

We use a 3D Monte Carlo radiative transfer code to study the projection of large shadows by circumstellar disks around young stellar objects on surrounding reflection nebulosity. It is shown that for a wide range of parameters a small…

Among the models proposed to account for the new component of diffuse EUV and soft X-ray emission from clusters of galaxies (first discovered in Virgo) are two key contestants: the non-thermal scenario which postulates a population of…

Optical long baseline interferometry was recently established as a technique capable of resolving stars and their circumstellar environments at the milliarcsecond (mas) resolution level. This high-resolution opens an entire new window to…

Context. The circumstellar disks ejected by many rapidly rotating B stars (so-called Be stars) offer the rare opportunity of studying the structure and dynamics of gaseous disks at high spectral as well as angular resolution. Aims. This…

We explore the pulsationally driven orbital mass ejection mechanism for Be star disc formation using isothermal, 3D magnetohydrodynamic (MHD) and hydrodynamic simulations. Non-radial pulsations are added to a star rotating at 95\% of…

The vertical density distribution of stars in a galactic disc is traditionally obtained by assuming an isothermal vertical velocity dispersion of stars. Recent observations from SDSS, LAMOST, RAVE, Gaia etc show that this dispersion…

We investigate the intrinsic continuum linear polarization from axisymmetric density distributions of gas surrounding classical Be stars during the formation and dissipation of their circumstellar disks. We implement a Monte Carlo…

(Abridged) A numerical model of a circumstellar debris disk is developed and applied to observations of the circumstellar dust orbiting beta Pictoris. The model accounts for the rates at which dust is produced by collisions among unseen…