搜索结果: 1-15 共查到“天文学 Protoplanetary”相关记录28条 . 查询时间(0.062 秒)
ALMA reveals planet-forming potential of protoplanetary disk
ALMA planet-forming potential protoplanetary disk
2016/2/23
Astronomers struggle to understand how planets form in binary star systems. Early models suggested that the gravitational tug-of-war between two stellar bodies would send young planets into eccentric ...
Evidence for Multiple Pathways to Deuterium Enhancements in Protoplanetary Disks
Evidence Multiple Pathways Deuterium Enhancements Protoplanetary Disks
2012/2/23
The distributions of deuterated molecules in protoplanetary disks are expected to depend on the molecular formation pathways. We use observations of spatially resolved DCN emission from the disk aroun...
Gaps in Protoplanetary Disks as Signatures of Planets: I. Methodology and Validation
planet disk interactions protoplanetary disks planets and satellites detection radiative
2012/2/23
We examine the observational consequences of partial gaps being opened by planets in protoplanetary disks. We model the disk using a static alpha-disk model with detailed radiative transfer, parametri...
Turbulent Linewidths in Protoplanetary Disks: Predictions from Numerical Simulations
Turbulent Linewidths Protoplanetary Disks: Predictions Numerical Simulations
2011/10/11
Sub-mm observations of protoplanetary disks now approach the acuity needed to measure the turbulent broadening of molecular lines. These measurements constrain disk angular momentum transport, and fur...
The outcome of protoplanetary dust growth: pebbles, boulders, or planetesimals? III. Sedimentation driven coagulation inside the snow-line
Methods Numerical Planets satellites formation Protoplanetary disks
2011/10/20
We investigate dust growth due to settling in a 1D vertical column of a protoplanetary disk. It is known from the observed 10 micron feature in disk SEDs, that small micron-sized grains are present at...
Chemical evolution of a protoplanetary disk
accretion disks astrochemistry diff usion line:formation molecular processes
2011/10/13
In this paper we review recent progress in our understanding of the chemical evolution of protoplanetary disks. Current observational constraints and theoretical modeling on the chemical composition o...
The propagation of Lyman-alpha in evolving protoplanetary disks
propagation Lyman-alpha evolving protoplanetary
2011/10/11
We study the role resonant scattering plays in the transport of Lyman-alpha photons in accreting protoplanetary disk systems subject to varying degrees of dust settling. While the intrinsic stellar FU...
Chemistry in a gravitationally unstable protoplanetary disc
stars: pre-main-sequence, stars: circumstellar matter, protoplanetary discs, astrochemistry
2011/10/9
Until now, axisymmetric, alpha-disc models have been adopted for calculations of the chemical composition of protoplanetary discs. While this approach is reasonable for many discs, it is not appropria...
The Role of Tiny Grains on the Accretion Process in Protoplanetary Disks
Tiny Grains Accretion Process Protoplanetary Disks
2011/10/9
Tiny grains such as PAHs have been thought to dramatically reduce the coupling between gas and magnetic fields in weakly ionized gas such as in protoplanetary disks (PPDs) because they provide tremend...
Magnetorotational Instability Driven Accretion in Protoplanetary Disks
Instability Driven Accretion Protoplanetary
2011/10/9
The gas dynamics in protoplanetary disks (PPDs) is strongly affected by non-ideal MHD effects. Using a complex chemical reaction network with standard prescriptions for X-ray and cosmic-ray ionization...
Chemical abundances in the protoplanetary disk LV2 (Orion) - II: High dispersion VLT observations and microjet properties
ISM – abundances HII regions ISM:stars: pre-main-sequence protostars protoplan- etary disks
2011/9/29
Integral field spectroscopy of the LV2 proplyd is presented taken with the VLT/FLAMES Argus array at an angular resolution of 0.31x0.31 arcsec^2 and velocity resolutions down to 2 km/s per pixel. Foll...
High-resolution simulations of planetesimal formation in turbulent protoplanetary discs
High-resolution simulations turbulent protoplanetary discs
2011/1/10
We present high-resolution computer simulations of dust dynamics and planetesimal formation in turbulence generated by the magnetorotational instability. We show that the turbulent viscosity associate...
Protoplanetary disks are quasi-steady structures whose evolution and dispersal determine the environ-ment for planet formation. I review the theory of protoplanetary disk evolution and its connection ...
The baroclinic instability in the context of layered accretion. Self-sustained vortices and their magnetic stability in local compressible unstratified models of protoplanetary disks
baroclinic instability magnetic stability protoplanetary disks
2010/11/10
Context. Turbulence and angular momentum transport in accretion disks remain a topic of debate. With the realization that dead zones are robust features of protoplanetary disks, the search for hydrody...
Chemistry of a protoplanetary disk with grain settling and Lyman alpha radiation
astrochemistry circumstellar matter ISM abundances ISM: molecules planetary systems
2010/11/10
We present results from a model of the chemical evolution of protoplanetary disks. In our models we directly calculate the changing propagation and penetration of a high energy radiation field with Ly...