相关论文: Predictions for the frequency and orbital radii of…

We present a statistical study of the post-formation migration of giant planets in a range of initial disk conditions. For given initial conditions we model the evolution of giant planet orbits under the influence of disk, stellar, and mass…

We quantify the utility of large radial velocity surveys for constraining theoretical models of Type II migration and protoplanetary disk physics. We describe a theoretical model for the expected radial distribution of extrasolar planets…

Observations of structure in circumstellar debris discs provide circumstantial evidence for the presence of massive planets at large (several tens of au) orbital radii, where the timescale for planet formation via core accretion is…

We use the model for the migration of planets introduced in Del Popolo, Yesilyurt & Ercan (2003) to calculate the observed mass and semimajor axis distribution of extra-solar planets. The assumption that the surface density in planetesimals…

Recent observations of exoplanets by direct imaging, reveal that giant planets orbit at a few dozens to more than a hundred of AU from their central star. The question of the origin of these planets challenges the standard theories of…

Doppler surveys have shown that more massive stars have significantly higher frequencies of giant planets inside $\sim$ 3 AU than lower mass stars, consistent with giant planet formation by core accretion. Direct imaging searches have begun…

There is evidence for the existence of massive planets at orbital radii of several hundred AU from their parent stars where the timescale for planet formation by core accretion is longer than the disc lifetime. These planets could have…

We use a semi-analytic circumstellar disk model that considers movement of the snow line through evolution of accretion and the central star to investigate how gas giant frequency changes with stellar mass. The snow line distance changes…

Outward migration of low-mass planets has recently been shown to be a possibility in non-barotropic disks. We examine the consequences of this result in evolutionary models of protoplanetary disks. Planet migration occurs towards…

Direct imaging observations of planets revealed that wide-orbit ($>10$ au) giant planets exist even around subsolar-metallicity host stars and do not require metal-rich environments for their formation. A possible formation mechanism of…

The apparent dependence of detection frequency of extrasolar planets on the metallicity of their host stars is investigated with Monte Carlo simulations using a deterministic core-accretion planet formation model. According to this model,…

We develop an idealized dynamical model to predict the typical properties of outer extrasolar planetary systems, at radii beyond 5 AU. Our hypothesis is that dynamical evolution in outer planetary systems is controlled by a combination of…

The migration of planets plays an important role in the early planet-formation process. An important problem has been that standard migration theories predict very rapid inward migration, which poses problems for population synthesis…

We extend the models presented in Mordasini et al. (2009) to the formation of planets orbiting stars of different masses. We discuss the properties of the resulting synthetic planet population in terms of mass, orbit, and metallicity…

Many extra-solar planets discovered over the past decade are gas giants in tight orbits around their host stars. Due to the difficulties of forming these `hot Jupiters' in situ, they are generally assumed to have migrated to their present…

Extrasolar planets abound in almost any possible configuration. However, until five years ago, there was a lack of planets orbiting closer than 0.5 au to giant or subgiant stars. Since then, recent detections have started to populated this…

In protoplanetary discs, planetary cores must be at least 0.1 earth mass at 1 au for migration to be significant; this mass rises to 1 earth mass at 5 au. Planet formation models indicate that these cores form on million year timescales. We…

To understand giant planet formation, we need to focus on host stars close to $1.7\ \rm M_{\odot}$, where the occurrence rate of these planets is the highest. In this initial study, we carry out pebble-driven core accretion planet formation…

The evidence for a shortage of exosolar planets with semimajor axes -1.1 <= log (a/AU) <= -0.2 is investigated. It is shown that this valley results from a gap in the radial distribution of planets, orbiting stars with masses M >= 1.2…

Planets orbiting a planetesimal circumstellar disc can migrate inward from their initial positions because of dynamical friction between planets and planetesimals. The migration rate depends on the disc mass and on its time evolution.…