相关论文: Testing Bimodal Planet Formation
In the coming years, high contrast imaging surveys are expected to reveal the characteristics of the population of wide-orbit, massive, exoplanets. To date, a handful of wide planetary mass companions are known, but only one such…
Continuing our study of the effects of secular resonances on the formation of terrestrial planets in moderately close binary stars, we present here the results of an extensive numerical simulations of the formation of these objects.…
Given the tendency of planets to form in multiples, and the observational evidence in support of the existence of potential planet-hosting stars in binaries or clusters, it is expected that extrasolar terrestrial planes are more likely to…
Disk instability is an attractive yet controversial means for the rapid formation of giant planets in our solar system and elsewhere. Recent concerns regarding the first adiabatic exponent of molecular hydrogen gas are addressed and shown…
Globular cluster systems in most large galaxies display bimodal color and metallicity distributions, which are frequently interpreted as indicating two distinct modes of cluster formation. The metal-rich (red) and metal-poor (blue) clusters…
Directly imaged planets are self-luminous companions of pre-main sequence and young main sequence stars. They reside in wider orbits ($\sim10\mathrm{s}-1000\mathrm{s}$~AU) and generally are more massive compared to the close-in ($\lesssim…
In this article we present a detailed spectroscopic analysis of more than 50 extra-solar planet host stars. Stellar atmospheric parameters and metallicities are derived using high resolution and high S/N spectra. The spectroscopy results,…
The present dynamical configuration of planets in binary star systems may not reflect their formation process since the binary orbit may have changed in the past after the planet formation process was completed. An observed binary system…
We explore two ways in which objects of planetary masses can form. One is in disk systems like the solar system. The other is in dense clusters where stars and brown dwarfs form. We do not yet have the instrumental accuracy to detect…
The frequency and properties of multiple star systems offer powerful tests of star formation models. Multiplicity surveys over the past decade have shown that binary properties vary strongly with mass, but the functional forms and the…
The observed extrasolar planets possess both large masses (with a median M sin i of 1.65 MJ) and a wide range in orbital eccentricity (0 < e < 0.94). As planets are thought to form in circumstellar disks, one important question in planet…
Binary star systems are assumed to be co-natal and coeval, thus to have identical chemical composition. In this work we aim to test the hypothesis that there is a connection between observed element abundance patterns and the formation of…
ALMA observations of dust ring/gap structures in a minority but growing sample of protoplanetary disks can be explained by the presence of planets at large disk radii - yet the origins of these planets remains debated. We perform planet…
We present preliminary results from our spectroscopic search for planets within 1 AU of metal-poor field dwarfs using NASA time with HIRES on Keck I. The core accretion model of gas giant planet formation is sensitive to the metallicity of…
A major outstanding question regarding the formation of planetary systems is whether wide-orbit giant planets form differently than close-in giant planets. We aim to establish constraints on two key parameters that are relevant for…
The current census of planetary systems displays a wide range of architectures. Extending earlier work, this paper investigates the correlation between our classification framework for these architectures and host stellar properties.…
(Abridged) We build a theoretical model to study the origin of the globular cluster metallicity bimodality in the hierarchical galaxy assembly scenario, based on the observed galaxy mass-[O/H] relation and the galaxy stellar mass function…
Recent observations of rocky super-Earths have revealed an apparent wider distribution of Fe/Mg ratios, or core to mantle ratios, than the planets in our Solar System. This study aims to understand how much of the chemical diversity in the…
Gas-giant exoplanets are test cases for theories of planet formation as their atmospheres are proposed to carry signatures of their formation within the protoplanetary disk. The metallicity and C/O are key diagnostics, allowing to…
The probability of a star hosting a planet that is detectable in radial velocity surveys increases Ppl(Z) oc 10^2Z, where Z is metallicity. Core accretion models reproduce this trend, since the protoplanetary disk of a high metallicity star…