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Related papers: A New Look at T Tauri Star Forbidden Lines: MHD Dr…

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We present optical spectrophotometric monitoring of four active T Tauri stars (DG Tau, RY Tau, XZ Tau, RW Aur A) at high spectral resolution ($R \ga 1 \times 10^4$), to investigate the correlation between time variable mass ejection seen in…

MHD turbulence plays a crucial role in the dust dynamics of protoplanetary discs. It affects planet formation, vertical settling and is one possible origin of the large scale axisymmetric structures, such as rings, recently imaged by ALMA…

Earth and Planetary Astrophysics · Physics 2018-10-03 A. Riols , G. Lesur

The removal of angular momentum from protostellar systems drives accretion onto the central star and may drive the dispersal of the protoplanetary disk. Winds and jets can contribute to removing angular momentum from the disk, though the…

Dust grains in the planet forming regions around young stars are expected to be heavily processed due to coagulation, fragmentation and crystallization. This paper focuses on the crystalline silicate dust grains in protoplanetary disks. As…

Winds play a significant role in active galactic nuclei feedback process. Previous simulations studying winds only focus on a small dynamical range. Therefore, it is unknown how far the winds can go and what the properties of the winds will…

High Energy Astrophysical Phenomena · Physics 2022-05-04 Yi Zhu , De-Fu Bu , Xiao-Hong Yang , Feng Yuan , Wen-Bin Lin

Massive stars present strong stellar that which are described by the radiation driven wind theory. Accurate mass-loss rates are necessary to properly describe the stellar evolution across the Hertzsprung--Russel Diagram. We present a…

Solar and Stellar Astrophysics · Physics 2019-03-20 Alex C. Gormaz-Matamala , Michel Curé , Lydia S. Cidale , Roberto O. J. Venero

The high luminosities of massive stars drive strong stellar winds, through line scattering of the star's continuum radiation. This paper reviews the dynamics of such line driving, building first upon the standard CAK model for steady winds,…

Solar and Stellar Astrophysics · Physics 2014-09-09 Stanley Owocki

Understanding dispersal of protoplanetary disks remains a central challenge in planet formation theory. Disk winds, driven by magnetohydrodynamics (MHD) and/or photoevaporation, are now recognized as primary agents of dispersal. With the…

Earth and Planetary Astrophysics · Physics 2026-02-25 R. Nakatani , G. Rosotti , B. Tabone , A. Sellek

It has recently been suggested that the winds from Classical T Tauri stars in general, and the wind from TW Hya in particular, reaches temperatures of at least 300,000 K while maintaing a mass loss rate of $\sim 10^{-11}$ \Msol yr$^{-1}$ or…

Astrophysics · Physics 2008-11-26 C. M. Johns-Krull , G. J. Herczeg

T Tauri stars produce broad Lyman-alpha emission lines that contribute $\sim$88% of the total UV flux incident on the inner circumstellar disks. Lyman-alpha photons are generated at the accretion shocks and in the protostellar chromospheres…

We present the first three-dimensional magnetohydrodynamic (MHD) simulations of the atmosphere of HD 209458b which self-consistently include reduction of winds due to the Lorentz force and Ohmic heating. We find overall wind structures…

Earth and Planetary Astrophysics · Physics 2015-06-18 T. M. Rogers , A. P. Showman

The dust sublimation walls of disks around T Tauri stars represent a directly observable cross-section through the disk atmosphere and midplane. Their emission properties can probe the grain size distribution and composition of the…

Earth and Planetary Astrophysics · Physics 2015-06-16 M. K. McClure , P. D'Alessio , N. Calvet , C. Espaillat , L. Hartmann , B. Sargent , D. M. Watson , L. Ingleby , J. Hernandez

Dust formation in the winds of hot stars is inextricably linked to the classic eruptive state of luminous blue variables (LBVs) because it requires very high mass loss rates, Mdot>10^(-2.5) Msun/year, for grains to grow and for the non-dust…

Solar and Stellar Astrophysics · Physics 2015-05-30 C. S. Kochanek

As a cool star evolves, it loses mass and angular momentum due to magnetized stellar winds which affect its rotational evolution. This change has consequences that range from the alteration of its activity to influences over the atmosphere…

Solar and Stellar Astrophysics · Physics 2023-07-26 Judy Chebly , Julián D. Alvarado-Gómez , Katja Poppenhäger , Cecilia Garraffo

In this study, we performed high-resolution near-infrared (NIR) spectroscopy (R = 28,000; ${\lambda} = 0.90$-1.35 ${\mu}$m) with a high signal-to-noise ratio on HD 200775, a very young (${\sim}$0.1 Myr old) and massive intermediate-mass…

We constrain wind parameters of a sample of 18 O-type stars in the LMC, through analysis with stellar atmosphere and wind models including the effects of optically thick clumping. This allows us to determine the most accurate spectroscopic…

Solar and Stellar Astrophysics · Physics 2024-10-09 C. Hawcroft , L. Mahy , H. Sana , J. O. Sundqvist , M. Abdul-Masih , S. A. Brands , L. Decin , A. deKoter , J. Puls

Most of the observed emission lines and continuum excess from young accreting low mass stars (Classical T Tauri stars -- CTTSs) take place in the star-disk or inner disk region. These regions have a complex emission topology still largely…

Astrophysics · Physics 2009-11-13 L. Podio , P. J. V. Garcia , F. Bacciotti , S. Antoniucci , B. Nisini , C. Dougados , M. Takami

The mechanisms of angular momentum transport and level of turbulence in protoplanetary disks (PPDs) are crucial for understanding many aspects of planet formation. In the recent years, it has been realized that the magneto-rotational…

Earth and Planetary Astrophysics · Physics 2020-03-11 Can Cui , Xue-Ning Bai

Protostellar jets are tightly connected to the accretion process and regulate the angular momentum balance of accreting star-disk systems. The DG Tau jet is one of the best-studied protostellar jets and contains plasma with temperatures…

Solar and Stellar Astrophysics · Physics 2015-06-12 P. C. Schneider , J. Eisloeffel , M. Guedel , H. M. Guenther , G. Herczeg , J. Robrade , J. H. M. M. Schmitt

We find a trend between the mid-infrared HCN/H2O flux ratio and submillimeter disk mass among T Tauri stars in Taurus. While it may seem puzzling that the molecular emission properties of the inner disk (< few AU) are related to the…

Solar and Stellar Astrophysics · Physics 2019-08-19 Joan R. Najita , John S. Carr , Klaus M. Pontoppidan , Colette Salyk , Ewine F. van Dishoeck , Geoffrey A. Blake