Results 21 to 30 of about 19,742 (238)
Annual Review of Astronomy and Astrophysics, 2023 Planets form in disks of gas and dust around young stars. The disk molecular reservoirs and their chemical evolution affect all aspects of planet formation, from the coagulation of dust grains into pebbles to the elemental and molecular compositions of the mature planet.
Öberg, Karin I. +2 more
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Vortices in Protoplanetary Disks [PDF]
The Astrophysical Journal, 1999 We use a high order accuracy spectral code to carry out two-dimensional time-dependent numerical simulations of vortices in accretion disks. In particular, we examine the stability and the life time of vortices in circumstellar disks around young stellar objects. The results show that cyclonic vortices dissipate quickly, while anticyclonic vortices can
Godon, Patrick., Livio, Mario.
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HNC IN PROTOPLANETARY DISKS [PDF]
The Astrophysical Journal, 2015 The distributions and abundances of small organics in protoplanetary disks are potentially powerful probes of disk physics and chemistry. HNC is a common probe of dense interstellar regions and the target of this study. We use the Submillimeter Array (SMA) to observe HNC 3--2 towards the protoplanetary disks around the T Tauri star TW Hya and the ...
Dawn Graninger +3 more
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Photoevaporation of Protoplanetary Disks [PDF]
The Astrophysical Journal, 2008 We present HST/NICMOS Paschen alpha images and low and high resolution IRS spectra of photoevaporating disk-tail systems originally detected at 24 micron near O stars. We find no Paschen alpha emission in any of the systems. The resulting upper limits correspond to about 0.000002-0.000003 solar mass of mass in hydrogen in the tails suggesting that the ...
George H. Rieke +7 more
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Protoplanetary Disks as (Possibly) Viscous Disks [PDF]
The Astrophysical Journal, 2017 Abstract Protoplanetary disks are believed to evolve on megayear timescales in a diffusive (viscous) manner as a result of angular momentum transport driven by internal stresses. Here we use a sample of 26 protoplanetary disks resolved by ALMA with measured (dust-based) masses and stellar accretion rates to derive the dimensionless α ...
Roman R. Rafikov, Roman R. Rafikov
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Dust evolution in protoplanetary disks [PDF]
Proceedings of the International Astronomical Union, 2007 AbstractWe investigate the behaviour of dust in protoplanetary disks under the action of gas drag using our 3D, two-fluid (gas+dust) SPH code. We present the evolution of the dust spatial distribution in global simulations of planetless disks as well as of disks containing an already formed planet.
Gonzalez, Jean-François +3 more
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The Dispersal of Protoplanetary Disks [PDF]
, 2014 Protoplanetary disks are the sites of planet formation, and the evolution and eventual dispersal of these disks strongly influences the formation of planetary systems. Disk evolution during the planet-forming epoch is driven by accretion and mass-loss due to winds, and in typical environments photoevaporation by high-energy radiation from the central ...
Alexander, Richard +4 more
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Ionization and heating by X-rays and cosmic rays*
EPJ 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
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Water in Protoplanetary Disks [PDF]
Proceedings of the International Astronomical Union, 2012 AbstractInfrared water line emission from protoplanetary disks, recently observed by the Spitzer and Herschel space telescopes, is thought to trace the surface layer of the inner to outer regions of the disks. We have modelled the water abundance profile and line emission, especially focusing on the effects of dust size growth and turbulent mixing ...
Nomura, H. +3 more
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Interferometry and the study of protoplanetary disks [PDF]
EPJ Web of Conferences, 2015 Interferometry offers access to scales that are unresolvable using single dish telescopes, which is especially important when investigating objects with small angular sizes, such as protoplanetary disks. This Chapter introduces the concept of interferometry, and describes the basic aspects of interferometric observations when considering long (i.e. sub-
Ilee, John David, Greaves, Jane Sophia
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