Results 11 to 20 of about 54,720 (190)

Ionization and heating by X-rays and cosmic rays*

open access: yesEPJ Web of Conferences, 2015
High-energy radiation from the central T Tauri and protostars plays an important role in shaping protoplanetary disks and influences their evolution. Such radiation, in particular X-rays and extreme-ultraviolet (EUV) radiation, is predominantly generated
Güdel Manuel
doaj   +1 more source

Rapid Formation of Gas-giant Planets via Collisional Coagulation from Dust Grains to Planetary Cores. II. Dependence on Pebble Bulk Density and Disk Temperature

open access: yesThe Astrophysical Journal, 2023
Thanks to “dust-to-planet” simulations (DTPSs), which treat the collisional evolution directly from dust to giant-planet cores in a protoplanetary disk, we showed that giant-planet cores are formed in ≲10 au in several 10 ^5 yr, because porous pebbles ...
Hiroshi Kobayashi, Hidekazu Tanaka
doaj   +1 more source

Structured Distributions of Gas and Solids in Protoplanetary Disks [PDF]

open access: yesarXiv, 2022
Recent spatially-resolved observations of protoplanetary disks revealed a plethora of substructures, including concentric rings and gaps, inner cavities, misalignments, spiral arms, and azimuthal asymmetries. This is the major breakthrough in studies of protoplanetary disks since Protostars and Planets VI and is reshaping the field of planet formation.
arxiv  

From Birth to Death of Protoplanetary Disks: Modeling Their Formation, Evolution, and Dispersal [PDF]

open access: yesMon.Not.Roy.Astron.Soc. 461 (2016) 2257, 2016
Formation, evolution, and dispersal processes of protoplanetary disks are investigated and the disk lifetime is estimated. Gravitational collapse of a pre-stellar core forms both a central star and a protoplanetary disk. The central star grows by accretion from the disk, and irradiation by the central star heats up the disk and generates thermal wind ...
arxiv   +1 more source

THE PROTOPLANETARY SYSTEM FORMATION AS A RESULT OF THE MERGING OF CLOSE BINARY STAR CONSISTING OF THE LOW MASS PRE-MS STARS

open access: yesOdessa Astronomical Publications, 2017
The mechanism of protoplanetary system formation as a result of a merge of binary star consisting of the low mass (0.5-1M⊙) pre-MS stars is considered. During the merging the more massive component is destroyed. The substance of the destroyed component
F. V. Sirotkin, V. G. Karetnikov
doaj   +1 more source

Kinematic Evidence of an Embedded Protoplanet in HD 142666 Identified by Machine Learning

open access: yesThe Astrophysical Journal, 2023
Observations of protoplanetary disks have shown that forming exoplanets leave characteristic imprints on the gas and dust of the disk. In the gas, these forming exoplanets cause deviations from Keplerian motion, which can be detected through molecular ...
J. P. Terry   +3 more
doaj   +1 more source

Gas-phase CO in protoplanetary disks: a challenge for turbulent mixing [PDF]

open access: yesAstrophys.J.647:L57-L60,2006, 2006
This is the first paper in a series where we study the influence of turbulent diffusion and advective transport on the chemical evolution of protoplanetary disks, using a 2D flared disk model and a 2D mixing gas-grain chemical code with surface reactions.
arxiv   +1 more source

Three-dimensional SPH Simulations of FU Orionis Star Flares in the Clumpy Accretion Model

open access: yesThe Astrophysical Journal, 2023
One of the early hypotheses about the origin of FU Orionis star (FUORs) outbursts explains them based on the fall of gas clumps from the remnants of protostellar clouds onto protoplanetary disks surrounding young stars.
Tatiana V. Demidova, Vladimir P. Grinin
doaj   +1 more source

Protoplanetary Disk Resonances and Type I Migration [PDF]

open access: yes2011, ApJ, 741, 109, 2011
Waves reflected by the inner edge of a protoplanetary disk are shown to significantly modify Type I migration, even allowing the trapping of planets near the inner disk edge for small planets in a range of disk parameters. This may inform the distribution planets close to their central stars, as observed by the Kepler mission.
arxiv   +1 more source

Gas Phase diagnostics of Protoplanetary disk extension [PDF]

open access: yes, 2008
We investigate the potential of using ratios of fine structure and near-infrared forbidden line transitions of atomic carbon to diagnose protoplanetary disk extension. Using results from 2D photoionisation and radiative transfer modeling of a realistic protoplanetary disk structure irradiated by X-rays from a T Tauri star, we obtain theoretical ...
arxiv   +1 more source

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