相关论文: Formation of Giant Planets by Disk Instability on …

Forming giant planets by disk instability requires a gaseous disk that is massive enough to become gravitationally unstable and able to cool fast enough for self-gravitating clumps to form and survive. Models with simplified disk cooling…

Gravitational instability has been invoked as a possible mechanism of giant planet formation in protoplanetary disks. Here we critically revise its viability by noting that for the direct production of giant planets it is not enough for…

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 recent discoveries of massive planets on ultra-wide orbits of HR 8799 (Marois et al. 2008) and Fomalhaut (Kalas et al. 2008) present a new challenge for planet formation theorists. Our goal is to figure out which of three giant planet…

Extrasolar planet surveys have begun to detect gas giant planets in orbit around M dwarf stars. While the frequency of gas giant planets around M dwarfs so far appears to be lower than that around G dwarfs, it is clearly not zero. Previous…

A new suite of three dimensional radiative, gravitational hydrodynamical models is used to show that gas giant planets are unlikely to form by the disk instability mechanism at distances of ~100 AU to ~200 AU from young stars. A similar…

Observational evidence suggests that gas disk instability may be responsible for the formation of at least some gas giant exoplanets, particularly massive or distant gas giants. With regard to close-in gas giants, Boss (2017) used the…

The formation of gas-giant planets within the lifetime of a protoplanetary disk is challenging especially far from a star. A promising model for the rapid formation of giant-planet cores is pebble accretion in which gas drag during…

The core-accretion mechanism for gas giant formation may be too slow to create all observed gas giant planets during reasonable gas disk lifetimes, but it has yet to be firmly established that the disk instability model can produce…

The disk instability (DI) model for giant planet formation remains an attractive alternative in explaining the formation of giant planets at early times, giant planets at large radial distances, and giant planets orbiting M-stars. In this…

Observational evidence exists for the formation of gas giant planets on wide orbits around young stars by disk gravitational instability, but the roles of disk instability and core accretion for forming gas giants on shorter period orbits…

Both core accretion and disk instability appear to be required as formation mechanisms in order to explain the entire range of giant planets found in extrasolar planetary systems. Disk instability is based on the formation of clumps in a…

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…

I argue for two modes of gas giant planet formation and discuss the conditions under which each mode operates. Gas giant planets at disk radii $r>100$ AU are likely to form in situ by disk instability, while core accretion plus gas capture…

We propose a pebble-driven core accretion scenario to explain the formation of giant planets around the late-M dwarfs of $M_{\star}{=}0.1{-}0.2 \ M_{\odot}$. In order to explore the optimal disk conditions for giant planet, we perform…

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…

We present a semi-analytical population synthesis model of protoplanetary clumps formed by disk instability at radial distances of 80 - 120 AU. Various clump density profiles, initial mass functions, protoplanetary disk models, stellar…

The discovery of giant planets in wide orbits represents a major challenge for planet formation theory. In the standard core accretion paradigm planets are expected to form at radial distances $\lesssim 20$ au in order to form massive cores…

Direct imaging observations constrain the fraction of stars orbited by gas giant planets with separations greater than 10 au to about 0.01 only. This is widely believed to indicate that massive protoplanetary discs rarely fragment on…

Planet formation is directly linked to the birthing environment that protoplanetary disks provide. The disk properties determine whether a giant planet will form and how it evolves. The number of exoplanet and disk observations is…