Related papers: Winds and Accretion in Young Stars
We examine a problem of the dust grains survival in the disk wind in T Tauri stars (TTSs). For consideration we choose the disk wind model described by Garcia et al. (2001), where a gas component of the wind is heated by an ambipolar…
We used the TNG/GIANO instrument to obtain near-IR high-resolution spectra (R~50000) of XZ Tau and DR Tau, two actively accreting T Tauri stars classified as EXors. The analysis of the observed features provides information on the…
Classical T Tauri stars (CTTS) accrete material from their discs through their magnetospheres. The geometry of the accretion flow strongly depends on the magnetic obliquity, i.e., the angle between the rotational and magnetic axes. We aim…
Radially extended disk winds could be the key to unlocking how protoplanetary disks accrete and how planets form and migrate. A distinctive characteristic is their nested morphology of velocity and chemistry. Here we report JWST/NIRSpec…
Magnetic fields in accretion disks play a dominant role during the star formation process but have hitherto been observationally poorly constrained. Field strengths have been inferred on T Tauri stars themselves and possibly in the…
An observational review is provided of the properties of accretion disks around young stars. It concerns the primordial disks of intermediate- and high-mass young stellar objects in embedded and optically revealed phases. The properties…
We investigate the dynamics of the accretion disks of young stars with fossil large-scale magnetic field. The author's magnetohydrodynamic (MHD) model of the accretion disks is generalized to consider the dynamical influence of the magnetic…
We construct models for the rotation rates of T Tauri stars whose spin is regulated by magnetic linkage between the star and a surrounding accretion disc. Our models utilise a time-dependent disc code to follow the accretion process and…
This paper reviews current theoretical work on the various stages of accretion in protostars, and the relationship of these ideal stages to the spectral classes of observed protostellar systems. I discuss scaling relationships that have…
We have studied numerically the evolution of protostellar disks around intermediate and upper mass T Tauri stars (0.25 M_sun < M_st < 3.0 M_sun) that have formed self-consistently from the collapse of molecular cloud cores. In the T Tauri…
The He I 1 micron line is a high excitation line which allows us to probe the innermost regions of protostellar disks, and to trace both accreting and outflowing material. We use X-Shooter observations of a sample of 107 young stars in the…
We model the mass accretion rate $\dot{M}$ to stellar mass $M_*$ correlation that has been inferred from observations of intermediate to upper mass T Tauri stars---that is $\dot{M} \propto M_*^{1.3 \pm 0.3}$. We explain this correlation…
Jets from young stars represent one of the most striking signposts of star formation. The phenomenon has been researched for over two decades and there is now general agreement that such jets are generated as a by-product of accretion; most…
Strong, kilo-Gauss, magnetic fields are required to explain a range of observational properties in young, accreting pre-main sequence (PMS) systems. We review the techniques used to detect magnetic fields in PMS stars. Key results from a…
We probe the geometry of magnetospheric accretion in classical T Tauri stars by modeling red absorption at He I 10830 via scattering of the stellar and veiling continua. Under the assumptions that the accretion flow is an azimuthally…
Sgr A* is an ideal target to study low-luminosity accreting systems. It has been recently proposed that properties of the accretion flow around Sgr A* can be probed through its interactions with the stellar wind of nearby massive stars…
Using Keck/HIRES spectra {\Delta}v ~ 7 km/s, we analyze forbidden lines of [O I] 6300 {\AA}, [O I] 5577 {\AA} and [S II] 6731 {\AA} from 33 T Tauri stars covering a range of disk evolutionary stages. After removing a high velocity component…
We review observational evidence and open issues related to the process of magnetospheric accretion in T Tauri stars. Emphasis is put on recent numerical simulations and observational results which suggest that the interaction between the…
Magnetohydrodynamic (MHD) and photoevaporative winds are thought to play an important role in the evolution and dispersal of planet-forming disks. We report the first high-resolution ($\Delta v\sim$6\kms) analysis of [S II] $\lambda$4068,…
From a long time series of high resolution (R=115,000) HARPS spectra and simultaneous broad-band photometry, we report new evidence for magnetospheric accretion as well as ejection processes in the nearly edge-on classical T Tauri star AA…