相关论文: Deep Pa$\beta$ Imaging of the Candidate Accreting …
We model the evolution of a Jupiter-mass protoplanet formed by the disk instability mechanism at various radial distances accounting for the presence of the disk. Using three different disk models, it is found that a newly-formed…
The canonical theory for planet formation in circumstellar disks proposes that planets are grown from initially much smaller seeds. The long-considered alternative theory proposes that giant protoplanets can be formed directly from…
Context. Protoplanetary disks are the birthplace of planets. As such, they set the initial chemical abundances available for planetary atmosphere formation. Thus, studying elemental abundances, molecular compositions, and abundance ratios…
Observations of the H66a recombination line from the ionized gas in the cluster of newly formed massive stars, G10.6-0.4, show that most of the continuum emission derives from the dense gas in an ionized accretion flow that forms an ionized…
We review results about protoplanetary disk models, protoplanet migration and formation of giant planets with migrating cores. We first model the protoplanetary nebula as an \alpha-accretion disk and present steady state calculations for…
Pebble accretion refers to the assembly of rocky planet cores from particles whose velocity dispersions are damped by drag from circumstellar disc gas. Accretion cross-sections can approach maximal Hill-sphere scales for particles whose…
Many dozens of circumstellar discs show signatures of sculpting by planets. To help find these protoplanets by direct imaging, we compute their broadband spectral energy distributions, which overlap with the JWST (James Webb Space…
The young massive Jupiters discovered with high-contrast imaging provide a unique opportunity to study the formation and early evolution of gas giant planets. A key question is to what extent gravitational energy from accreted gas…
We present the first high-resolution X-ray spectrum of a prototypical Herbig star (AB Aurigae), measure and interpret various spectral features, and compare our results with model predictions. We use X-ray spectroscopy data from XMM-Newton.…
Recently, gas giant planets in nearly circular orbits with large semimajor axes ($a \sim$ 30--1000AU) have been detected by direct imaging. We have investigated orbital evolution in a formation scenario for such planets, based on core…
In this paper we present mid-infrared spectra of a comprehensive set of Herbig Ae/Be stars observed with the Spitzer Space Telescope. The signal-to-noise ratio of these spectra is very high, ranging between about a hundred and several…
*Context The evolution of young massive protoplanetary disks toward planetary systems is expected to include the formation of gaps and the depletion of dust and gas. *Aims A special group of flaring disks around Herbig Ae/Be stars do not…
According to the core-accretion scenario, planets form in protostellar disks through the condensation of dust, coagulation of planetesimals, and emergence of protoplanetary embryos. At a few AU in a minimum mass nebula, embryos' growth is…
As the number of planetary mass objects (PMOs, $\lessapprox$13 M$_{\rm{Jupiter}}$) at wider separation ($\gtrapprox$10 AU) grows, there is emerging evidence that they form differently from their higher-mass brown-dwarf (BD) counterparts.…
We review recent theoretical progress aimed at understanding the formation and the early stages of evolution of giant planets, low-mass stars and brown dwarfs. Calculations coupling giant planet formation, within a modern version of the…
Recent high-sensitivity observations reveal that accreting giant planets embedded in their parental circumstellar disks can emit H$\alpha$ at their final formation stages. While the origin of such emission is not determined yet,…
Context. The {\beta} Pictoris system with its debris disk and a massive giant planet orbiting at \simeq 9 AU represents an ideal laboratory to study giant planet formation and evolution as well as planet-disk interactions. {\beta} Pic b can…
We present dust continuum observations of the protoplanetary disk surrounding the pre-main sequence star AS 209, spanning more than an order of magnitude in wavelength from 0.88 to 9.8 mm. The disk was observed with sub-arcsecond angular…
Thanks to recent high resolution ALMA observations, there is an accumulating evidence for presence of giant planets with masses from $\sim 0.01$ Jupiter mass to a few Jupiter mass with separations up to $ 100$~AU in the annular structures…
We critically examine the best lines of evidence for grain growth in protoplanetary disks, based on modelling of observed spectral energy distributions and images of T Tauri and Herbig Ae stars. The data are consistent with millimeter-sized…