منابع مشابه
Collisional processes and size distribution in spatially extended debris discs
Context. New generations of instruments provide, or are about to provide, pan-chromatic images of debris discs and photometric measurements , that requires new generations of models, to in particular account for their collisional activity. Aims. We present a new multi–annulus code for the study of collisionally evolving extended debris discs. We first wish to confirm and extend our early result...
متن کاملSize distributions of dust in circumstellar debris discs
The size distribution of particles in a dust disc is determined by, and holds the key to, sources, sinks and dynamics of grains. Here we derive the size distribution in circumstellar debris discs, exemplified by the disc of β Pictoris, by modelling the dynamical evolution of the circumstellar dust, dominated by collisions. The whole disc is considered as consisting of two dust populations: larg...
متن کاملAtomic gas in debris discs
We have conducted a search for optical circumstellar absorption lines in the spectra of 16 debris disc host stars. None of the stars in our sample showed signs of emission line activity in either Hα, Ca II or Na I, confirming their more evolved nature. Four stars were found to exhibit narrow absorption features near the cores of the photospheric Ca II and Na I D lines (when Na I D data were ava...
متن کاملOn Grain Dynamics in Debris Discs: Continuous Outward Flows and Embedded Planets
This study employed grain dynamic models to examine the density distribution of debris discs, and discussed the effects of the collisional time-intervals of asteroidal bodies, the maximum grain sizes, and the chemical compositions of the dust grains of the models, in order to find out whether a steady out-moving flow with an 1/R profile could be formed. The results showed that a model with new ...
متن کاملVertical structure of debris discs
Context. The vertical thickness of debris discs is often used as a measure of these systems’ dynamical excitation, and as clues to the presence of hidden massive perturbers such as planetary embryos. However, this argument might be flawed because the observed dust should be naturally placed on inclined orbits by the combined effect of radiation pressure and mutual collisions. Aims. We criticall...
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ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2013
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361/201322052