相关论文: Non-linear pulsations in Wolf-Rayet stars

Classical Wolf-Rayet stars are descendants of massive OB-type stars that have lost their hydrogen-rich envelopes, and are in the final stages of stellar evolution, possibly exploding as type Ib/c supernovae. It is understood that the…

Wolf-Rayet stars (WRs) are evolved massive stars in the brief stage before they undergo core collapse. Not only are they rare, but they also can be particularly difficult to find due to the high extinction in the Galactic plane. This paper…

Parameter regions in which stars can become pulsationally unstable are found throughout the Hertzsprung-Russel diagram. Stars of high, intermediate, low and very low masses may cross various instability regions along their paths of…

We show that the rms-flux relation recently discovered in the X-ray light curves of Active Galactic Nuclei (AGN) and X-ray binaries (XRBs) implies that the light curves have a formally non-linear, exponential form, provided the rms-flux…

Pulsation period changes in Mira type variables are investigated using the stellar evolution and nonlinear stellar pulsation calculations. We considered the evolutionary sequence of stellar models with initial mass 3 Msol and population I…

We study a nonlinear development of radial pulsation instability to a resonant excitation of nonradial modes. Our theory covers the cases of axisymmetric (m=0) modes as well as (m,-m) pairs. Adopting a simplified treatment of the radial and…

Wolf-Rayet (WR) stars, as they are advanced stages of the life of massive stars, provide a good test for various physical processes involved in the modelling of massive stars, such as rotation and mass loss. In this paper, we show the…

Space photometry has revealed rich pulsation spectra in classical Be stars. Often frequency pairs can be found that differ by nearly the frequency of a third genuine stellar variability. The lowest currently known of these so-called…

We consider both mode calculations and time evolutions of axial r-modes for relativistic uniformly rotating non-barotropic neutron stars, using the slow-rotation formalism, in which rotational corrections are considered up to linear order…

We use radiation-hydrodynamical simulations to investigate the formation and synthetic X-ray emission of hot bubbles within planetary nebulae (PNe) driven by the powerful winds of H-deficient, [Wolf-Rayet]([WR])-type stars. Our models,…

We have computed the time evolution of bolometric, far-infrared, Halpha line, ultraviolet (both intrinsic and escaping the star forming region) and the nonthermal radio continuum luminosities for continuous and constant star formation. The…

Super-Eddington luminosities in hydrostatic model atmospheres manifest themselves by the presence of gas pressure inversions. Such inversions are not an artifact of the assumption of hydrostatic equilibrium but can also be present in…

A nonlinear dynamics of the thermal and electromagnetic instability of critical state in type II superconductors has been analysed taking into account effects of dissipation and dispersion. An existance of a nonlinear running waves…

We have carried out the first survey of the pulsational line profile variability in rapidly oscillating Ap (roAp) stars. We analysed high signal-to-noise time-series observations of ten sharp-lined roAp stars obtained with the…

We use $N$-body simulations to probe the early phases of the dynamical evolution of star-forming regions and focus on mass and velocity distributions of unbound stars. In this parameter space study, we vary the initial virial ratio and…

We construct helium (He) star models with optically thick winds and compare them with the properties of Galactic Wolf-Rayet (WR) stars. Hydrostatic He-core solutions are connected smoothly to trans-sonic wind solutions that satisfy the…

We construct an analytic model for the breakout of a relativistic radiation mediated shock from a stellar wind, and exploit it to calculate the observational diagnostics of the breakout signal. The model accounts for photon escape through…

We aimed at finding a physical explanation for the occurrence of macroturbulence in the atmospheres of hot massive stars, a phenomenon found in observations since more than a decade but yet unexplained. We computed time series of line…

We investigate the unusual emission line luminosity ratios observed in the JADES NIRSpec spectroscopy of GN-z11, which reveal exceptionally strong emission lines and a significant detection of the rarely observed N III]…

Observed properties of Wolf-Rayet stars at high metallicity are reviewed. Wolf-Rayet stars are more common at higher metallicity, as a result of stronger mass-loss during earlier evolutionary phases with late WC subtypes signatures of solar…