相关论文: Orphaned Protostars
Motivated by recent observational and numerical studies suggesting that collapsing protostellar cores may be replenished from the local environment, we explore the evolution of protostellar cores submerged in the external counter-rotating…
The accretion history of protostars remains widely mysterious even though it represents one of the best ways to understand the protostellar collapse that leads to the formation of stars. Molecular outflows are here used to characterize the…
We investigate the occurrence of classical (type-I) Cepheid variable stars (henceforth: Cepheids) in dynamically evolving star clusters from birth to an age of approximately 300 Myr. The clusters are modelled by the Aarseth code nbody6, and…
Observations with modern instruments such as Herschel reveal that stars form clustered inside filamentary arms of ~1 pc length embedded in Giant Molecular Clouds. On smaller scales (~1000 au), observations of, e.g., IRAS 16293--2422 show…
The relationship between young stellar clusters and respective parental molecular clouds is still an open issue: for instance, are the similarities between substructures of clouds and clusters just a coincidence? Or would they be the…
We explore the conditions prevailing in primordial planets in the framework of the HGD cosmologies as discussed by Gibson and Schild. The initial stages of condensation of planet-mass H-4He gas clouds in trillion-planet clumps is set at…
Exoplanetary systems are found not only among single stars, but also binaries of widely varying parameters. Binaries with separations of 100--1000 au are prevalent in the Solar neighborhood; at these separations planet formation around a…
We investigated the formation of arc-like structures in the infalling envelope around protostars, motivated by the recent Atacama Large Millimeter/Submillimeter Array (ALMA) observations of the high-density molecular cloud core,…
Fomalhaut is a triple system, with all components widely separated (~1E5 au). Such widely separated binaries are thought to form during cluster dissolution, but that process is unlikely to form such a triple system. We explore an…
We characterise the population of wandering black holes, defined as those physically offset from their halo centres, in the Romulus cosmological simulations. Unlike most other currently available cosmological simulations, black holes are…
As natural consequences of the accretion process, outflows are one of the few (indirect) tracers of accretion. We used CO(2-1) PdBI observations towards 6 MDCs in Cygnus-X, containing 9 high-mass cores, to investigate what the accretion…
The young stellar population data of the Perseus, Ophiuchus and Serpens molecular clouds are obtained from the Spitzer c2d legacy survey in order to investigate the spatial structure of embedded clusters using the nearest neighbour and…
The large number of observed exoplanets ($\gtrsim $ 700) provides important constraints on their origin as deduced from the mass-period diagram of planets. The most surprising features in the diagram are 1) the (apparent) pile up of gas…
Observed protostellar outflows exhibit a variety of asymmetrical features, including remarkable unipolar outflows and bending outflows. Revealing the formation and early evolution of such asymmetrical protostellar outflows, especially the…
We have performed Monte Carlo simulations of the trajectories of several runaway stars using their parallaxes and proper motions from the Gaia EDR3 catalogue. We have confirmed the hypothesis that the stars AE Aur and $\mu$Col are a product…
The theory of how low mass stars form from the collapse of a dense molecular cloud core has been well-established for decades. Thanks to significant progress in computing and numerical modelling, more physical models have been developed and…
We have searched the L1340 A, B, and C clouds for shocks from protostellar outflows using the H$_2$ 2.122 $\mu$m near-IR line as a shock tracer. Substantial outflow activity has been found in each of the three regions of the cloud (L1340 A,…
Runaway stars are OB-type stars ejected from their birthplace with large peculiar velocities. The leading hypothesis addressed in their formation includes the supernova ejection mechanism and the dynamic ejection scenario. Identification of…
We examine the spatial distribution of brown dwarfs produced by the decay of small-N stellar systems as expected from the embryo ejection scenario. We model a cluster of several hundred stars grouped into 'cores' of a few stars/brown…
Fomalhaut A is among the most well-studied nearby stars and has been discovered to possess a putative planetary object as well as a remarkable eccentric dust belt. This eccentric dust belt has often been interpreted as the dynamical…