Results 91 to 100 of about 2,982 (223)

Multiwavelength Dust Characterization of the HL Tau Disk and Implications for Planet Formation

The Astrophysical Journal
We present a comprehensive analysis of the HL Tau dust disk by modeling its intensity profiles across six wavelengths (0.45–7.9 mm) with a resolution of 0 $\mathop{.}\limits^{^{\prime\prime} }$ 05 (∼7 au). Using a Markov Chain Monte Carlo (MCMC) approach,
Takahiro Ueda, Sean M. Andrews, Carlos Carrasco-González, Osmar M. Guerra-Alvarado, Satoshi Okuzumi, Ryo Tazaki, Akimasa Kataoka   +6 more
doaj   +1 more source

Velocity Structure of Circumstellar Environment around Class 0/I Protostars: Uncertainty in the Protostellar Mass Estimation Using Circumstellar Velocities

The Astrophysical Journal
Recent high-resolution observations have enabled detailed investigations of the circumstellar environments around Class 0/I protostars. Several studies have reported that the infall velocity of the envelope is a few times smaller than the freefall ...
Shingo Hirano, Yuri Aikawa, Masahiro N. Machida   +2 more
doaj   +1 more source

The 12CO gas structures of protoplanetary disks in the Upper Scorpius region

Astronomy & Astrophysics
We present measurements of key protoplanetary disk properties inferred from parametric models of ALMA 12CO spectral line visibilities. We derived gas-disk radii, integrated fluxes, optically thick emission layers, and brightness temperature profiles for ...
Zallio Luigi, Rosotti Giovanni P., Vioque Miguel, Miotello Anna, Andrews Sean M., Manara Carlo F., Carpenter John M., Empey Aaron, Kurtovic Nicolás T., Law Charles J., Longarini Cristiano, Paneque-Carreño Teresa, Teague Richard, Villenave Marion, Yen Hsi-Wei, Zagaria Francesco   +15 more
doaj   +1 more source

Reference-less algorithm for circumstellar disks imaging

, 2018
Circumstellar disks play a key role in the understanding of stellar systems. Direct imaging of such extended structures is a challenging task. Current post-processing techniques, first tailored for exoplanets imaging, tend to produce deformed images of ...
Pairet, Benoît, Cantalloube, Faustine, Jacques, Laurent, International Traveling Workshop on Interactions Between Sparse Models and Technology (iTWIST'19)   +3 more
core  

Modeling sgB[e] Circumstellar Disks

, 2017
During their evolution, massive stars are characterized by a significant loss of mass either via spherically symmetric stellar winds or by aspherical mass-loss mechanisms, namely outflowing equatorial disks.
Feldmeier, Achim (Prof. Dr.), Kurfürst, P., Krtička, Jiri   +2 more
core  

Probing Dust and Gas Properties Using Ringed Disks

The Astrophysical Journal Letters
How rapidly a planet grows in mass and how far it may park from the host star depend sensitively on two nondimensional parameters: Stokes number St and turbulent α .
Eve J. Lee
doaj   +1 more source

Methanol Masers as Tracers of Circumstellar Disks

, 1998
We show that in many methanol maser sources the masers are located in lines, with a velocity gradient along them which suggests that the masers are situated in edge-on circumstellar, or protoplanetary, disks.
Phillips, CJ (15475688), Byleveld, SE (15482594), Troup, ER (15482600), Wellington, KJ (15482603), Norris, RP (15475670), Simon Ellingsen (14735971), Peter McCulloch (14743786), Tzioumis, AK (15475700), Takahashi, Y (5387725), Gough, RG (15475706), Reynolds, JE (15475697), Kesteven, MJ (15478130), Diamond, PJ (15482597), Ferris, RH (15475748)   +13 more
core  

Eccentric Disks with Self-gravity

The Astronomical Journal
Can a disk orbiting a central body be eccentric, when the disk feels its own self-gravity and is pressureless? Contradictory answers appear in the literature. We show that, to linear order in eccentricity, such a disk can be eccentric, but only if it has
Yoram Lithwick, Eugene Chiang, Leon Mikulinsky, Zhenbang Yu   +3 more
doaj   +1 more source

Studies of Young, Star-forming Circumstellar Disks [PDF]

Disks of gas and dust around forming stars -- circumstellar disks -- last only a few million years. This is a very small fraction of the entire lifetime of Sun-like stars, several billion years.
Bae, Jaehan
core  

Rapid planetesimal formation in turbulent circumstellar disks

, 2007
During the initial stages of planet formation in circumstellar gas disks, dust grains collide and build up larger and larger bodies. How this process continues from metre-sized boulders to kilometre-scale planetesimals is a major unsolved problem ...
Henning, Thomas, Jeffrey S. Oishi, Anders Johansen, Johansen, Anders, Mordecai-Mark Mac Low, Youdin, Andrew, Klahr, Hubert, Thomas Henning, Andrew Youdin, Low, Mordecai Mark Mac, Hubert Klahr, Oishi, Jeffrey S., Low, Mordecai-Mark Mac   +12 more
core   +1 more source