相关论文: Grain Destruction in Interstellar Shocks

We consider the survival of solid H2 in the diffuse interstellar medium, with application to grains which are small enough to qualify as dust. Consideration of only the thermal aspects of this problem leads to the familiar conclusion that…

The abundance of both amorphous and crystalline silicates in very small grains is limited by the fact that the 10 micron silicate emission feature is not detected in the diffuse ISM. On the basis of the observed IR emission spectrum for the…

In this paper we study the effects of inclusions and porosities on the emission properties of silicate grains and compare the model curves with the observed infrared emission from circumstellar dust. We calculate the absorption efficiency…

The temperature in the optically thick interior of protoplanetary discs is essential for the interpretation of millimeter observations of the discs, for the vertical structure of the discs, for models of the disc evolution and the planet…

We study the dynamics of large dust grains >1 micron with orbits outside of the heliosphere (beyond 250 AU). Motion of the Solar System through the interstellar medium (ISM) at a velocity of 26 km/s subjects these particles to gas and…

We are living in a dusty universe: dust is ubiquitously seen in a wide variety of astrophysical environments, ranging from circumstellar envelopes around cool red giants to supernova ejecta, from diffuse and dense interstellar clouds and…

We study the hydrodynamical behavior occurring in the turbulent interaction zone of a fast moving red supergiant star, where the circumstellar and interstellar material collide. In this wind-interstellar medium collision, the familiar bow…

Multi-wavelength spectroscopy can be used to constrain the dust and gas properties in debris disks. Circumstellar dust absorbs and scatters incident stellar light. The scattered light is sometimes resolved spatially at visual and…

The influence of a dust grain mixture consisting of spherical dust grains with different radii and/or chemical composition on the resulting temperature structure and spectral energy distribution of a circumstellar shell is investigated. The…

The Breakthrough Starshot initiative aims to launch a gram-scale spacecraft to a speed of $v\sim 0.2$c, capable of reaching the nearest star system, $\alpha$ Centauri, in about 20 years. However, a critical challenge for the initiative is…

The Earth and other rocky bodies in the inner solar system contain significantly less carbon than the primordial materials that seeded their formation. These carbon-poor objects include the parent bodies of primitive meteorites, suggesting…

We investigate the effect of fragmentation on the homogeneous free cooling of inelastic hard spheres, using Boltzmann kinetic theory and Direct Monte Carlo simulations. We analyze in detail a model where dissipative collisions may…

In many models of dusty objects in space the grains are assumed to be composite or fluffy. However, the computation of the optical properties of such particles is still a very difficult problem. We analyze how the increase of grain porosity…

Interstellar dust spans a wide range in size distribution, ranging from ultrasmall grains of a few Angstroms to micrometer-size grains. While the presence of nanometer-size dust grains in the Galactic interstellar medium was speculated six…

Super-puffs -- low-mass exoplanets with extremely low bulk density -- are attractive targets for exploring their atmospheres and formation processes. Recent studies suggested that the large radii of super-puffs may be caused by atmospheric…

Atoms and molecules, and in particular CO, are important coolants during the evolution of interstellar star-forming gas clouds. The presence of dust grains, which allow many chemical reactions to occur on their surfaces, strongly impacts…

Context. Matter that falls onto a protoplanetary disk (PPD) from a protostellar envelope is heated before it cools again. This induces sublimation and subsequent re-adsorption of ices that accumulated during the prestellar phase. Aims. We…

The recent detection of interstellar polarization in the solid CO feature near 4.67 micron shows that CO-mantled grains can be aligned in cold molecular clouds. These observations conflict with a theory of grain alignment which attributes…

The bulk composition of the Earth is dramatically carbon poor compared to that of the interstellar medium, and this phenomenon extends to the asteroid belt. To interpret this carbon deficit problem, the carbonaceous component in grains must…

From small seeds falling from trees to asteroids colliding with planets and moons, the impact of projectiles onto granular targets occurs in nature at different scales. In this paper, we investigate open questions in the mechanics of…