Related papers: Encounters in the ONC - observing imprints of star…
The nuclei of galaxies often host small stellar discs with scale-lengths of a few tens of parsecs and luminosities up to 10^7 Lsun. To investigate the formation and properties of nuclear stellar discs (NSDs), we look for their presence in a…
The gravitational interaction between a protoplanetary disc and planetary sized bodies that form within it leads to the exchange of angular momentum, resulting in migration of the planets and possible gap formation in the disc for more…
Could the velocity spread, increasing with time, in the Galactic disk be explained as a result of gravitational interactions of stars with giant molecular clouds (GMCs) and spiral arms? Do the old open clusters high above the Galactic plane…
We discuss the structure of a central stellar cluster whose dynamics is influenced by gravitation of a supermassive black hole and by the dissipative interaction of orbiting stars with an accretion disc. We also take the effect of disc…
The existence of giant planets on wide orbits ($\stackrel{>}{_\sim}100$AU) challenge planet formation theories; the core accretion scenario has difficulty in forming them, whereas the disc instability model forms an overabundance of them…
We study the circumstances under which first collisions occur in young and dense star clusters. The initial conditions for our direct $N$-body simulations are chosen such that the clusters experience core collapse within a few million…
Most, if not all, young stars are initially surrounded by protoplanetary disks. Owing to the preferential formation of stars in stellar clusters, the protoplanetary disks around these stars may potentially be affected by the cluster…
We have analyzed a number of intense X-ray flares observed in the Chandra Orion Ultradeep Project (COUP), a 13 days observation of the Orion Nebula Cluster (ONC). Analysis of the flare decay allows to determine the size, peak density and…
Stars in the Galactic disc, including the Solar system, have deviated from their birth orbits and have experienced radial mixing and vertical heating. By performing hydrodynamical simulations of a galactic disc, we investigate how much…
The primary aim of this work is to examine the effect of parabolic stellar encounters on the evolution of a Jovian-mass giant planet forming within a protoplanetary disc. We consider the effect on both the mass accretion and the migration…
Context: The brightness of FUors increases by several magnitudes within one to several years. The currently favoured explanation for this brightness boost is that of dramatically rising accretion from the disc material around a young star.…
HST images of proplyds in the Orion Nebula, as well as submillimeter/radio measurements, show that the dominant O7 star Theta1 Ori C photoevaporates nearby disks around pre-main sequence stars. Theory predicts that massive stars…
We carry out three-dimensional hydrodynamical simulations to study planet-disc interactions for inclined high mass planets, focusing on the disc's secular evolution induced by the planet. We find that, when the planet is massive enough and…
We numerically investigate orbital evolution of star clusters (SCs) under the influence of dynamical friction by field stars of their host disk galaxies embedded in dark matter halos. We find that SCs with masses larger than 2 * 10^5 M_sun…
Globular clusters (GCs) are known to harbor multiple stellar populations. To explain these observations Bastian et al. suggested a scenario in which a second population is formed by the accretion of enriched material onto the low-mass stars…
While the population of main sequence debris discs is well constrained, little is known about debris discs around evolved stars. This paper provides a theoretical framework considering the effects of stellar evolution on debris discs,…
The Orion Nebula Cluster (ONC) is the closest site of very young ($\sim$ 1 Myrs) massive star formation. The ONC hosts more than 1600 young and X-ray bright stars with masses ranging from $\sim$ 0.1 to 35 $M_\odot$. The Chandra HETGS Orion…
The study of protoplanetary disc evolution and planet formation has mainly concentrated on solar (and low) mass stars since they host the majority of the confirmed exoplanets. Nevertheless, the numerous planets found orbiting stars up to…
Observations of young star-forming regions suggest that star clusters are born completely mass segregated. These initial conditions are, however, gradually lost as the star cluster evolves dynamically. For star clusters with single stars…
Misalignments between the orbital planes of planets and the equatorial planes of their host stars have been observed in our solar system, in transiting exoplanets, and in the orbital planes of debris discs. We present a mechanism that…