相关论文: Oscillatory secular modes: The thermal micropulses

We consider the possibility that a mass of ~10^{-5}-10^{-3} Msun flows back from the dense shell of planetary nebulae and is accreted by the central star during the planetary nebula phase. This backflowing mass is expected to have a…

We investigate the instabilities and bifurcations of traveling pulses in a model excitable medium; in particular we discuss three different scenarios for the loss of stability resp. the disappearance of stable pulses. In numerical…

Very massive stars are thought to be formed in the early Universe because of a lack of cooling process by heavy elements, and might have been responsible for the later evolution of the Universe. We had an interest in vibrational stability…

In recent years, astronomers have witnessed major progresses in the field of stellar physics. This was made possible thanks to the combination of a solid theoretical understanding of the phenomena of stellar pulsations and the availability…

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 consider the problem of self-regulated heating and cooling in galaxy clusters and the implications for cluster magnetic fields and turbulence. Viscous heating of a weakly collisional magnetised plasma is regulated by the pressure…

We calculate steady-state, one-dimensional hydrodynamic profiles of hot gas in slowly accreting ("quiescent") galactic nuclei for a range of central black hole masses $M_{\bullet}$, parametrized gas heating rates, and…

We have derived a set of equations to describe the thermal evolution of a neutron star which undergoes small-amplitude radial pulsations. We have taken into account, in the frame of the General Theory of Relativity, the pulsation damping…

The gas in galaxy clusters is heated by shock compression through accretion (outer shocks) and mergers (inner shocks). These processes additionally produce turbulence. To analyse the relation between the thermal and turbulent energies of…

In massive objects, such as galaxy clusters, the turbulent velocity dispersion, $\sigma_\mathrm{turb}$, is tightly correlated to both the object mass, $M$, and the thermal energy. Here, we investigate whether these scaling laws extend to…

We present a theoretical model for the thermal X-ray emission and cooling of isolated pulsars, assuming that pulsars are solid quark stars. We calculate the heat capacity for such a quark star, and the results show that the residual thermal…

Thermal instability driven by radiation pressure might be relevant for intrinsically bright accreting sources. The most promising candidate where this instability seems to be at work is one of the two known galactic superluminal sources,…

The RS CVn type binary star GT Mus was observed during its quiescence using the Resolve X-ray microcalorimeter spectrometer onboard XRISM. The main and satellite lines of the Fe XXIV--XXVI K-shell transitions were resolved for the first…

We examine the stability of a low-mass stellar system surrounding a massive central object. Examples of such systems include the centers of galaxies or star clusters containing a massive black hole, and the Oort comet cloud. If the…

Plasma with a temperature close to the chromospheric one is ejected in solar eruptions. Such plasma can occult some part of emission of compact sources in active regions as well as quiet solar areas. Absorption phenomena can be observed in…

In certain mass ranges, massive stars can undergo a violent pulsation triggered by the electron/positron pair instability that ejects matter, but does not totally disrupt the star. After one or more of these pulsations, such stars are…

We study the mass distribution of a sample of 24 X-ray bright Abell clusters through weak gravitational lensing. This method is independent of the dynamical state of the galaxy cluster. Hence, by comparing dynamical and lensing mass…

We examine the energy-resolved pulse profiles of 51 flux oscillations observed during the decline of thermonuclear X-ray bursts from accreting weakly- magnetized neutron stars with the Rossi X-ray Timing Explorer. We find that the…

The temperature in most parts of a protoplanetary disk is determined by irradiation from the central star. Numerical experiments of Watanabe \& Lin (2008) suggested that such disks, also called `passive disks', suffer from a thermal…

The stability of a rotating flow in a triaxial ellipsoidal shell with an imposed temperature difference between inner and outer boundaries is studied numerically. We demonstrate that (i) a stable temperature field encourages the tidal…