Journal Article10.1086/300428
Emission-Line Diagnostics of T Tauri Magnetospheric Accretion. I. Line Profile Observations
TL;DR: In this article, the authors present high-resolution spectra of T Tauri stars in Taurus in the range 5800-9000 A to critically examine the current theories of magnetospheric accretion.
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Abstract: We present high-resolution spectra of classical T Tauri stars in Taurus in the range 5800–9000 A to critically examine the current theories of magnetospheric accretion. In this paper, we focus on the emission lines of hydrogen (the higher Paschen series and Hα), He I λ5876, O I λ7773 and λ8446, the Na D lines, and the Ca II infrared triplet. We argue that the magnetospheric infall zone is the likely source of emission for the hydrogen, oxygen, and sodium lines for most of the stars in our sample. As has been previously shown, the calcium and helium lines have a narrow and a broad component; focusing on the broad components, we find that they are likely formed in the magnetosphere for at least several of the stars in the sample. Preliminary calculations indicate that the magnetospheric models developed to explain the Balmer lines predict significant Ca II, Paschen, and O I emission, roughly comparable to what is observed. However, in some of the stars, especially at high veilings, the case for line formation in the accretion flow is not clear. Finally, our results suggest that the Ca II IR triplet lines are good indicators of the accretion rate for all but the most weakly accreting T Tauri stars.
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Circumstellar Dust Disks in Taurus-Auriga: The Submillimeter Perspective
TL;DR: In this paper, a multwavelength submillimeter survey of 153 young stellar objects in the Taurus-Auriga star formation region is presented, with a detection rate of 61% to a completeness limit of 10 mJy (3 � ) at850� m.
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Circumstellar Dust Disks in Taurus-Auriga: The Submillimeter Perspective
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The Mass Accretion Rates of Intermediate-Mass T Tauri Stars
Nuria Calvet,Nuria Calvet,James Muzerolle,James Muzerolle,Cesar Briceno,Cesar Briceno,Jesús Hernández,Jesús Hernández,Lee Hartmann,José Saucedo,José Saucedo,Karl D. Gordon +11 more
TL;DR: In this article, the authors used the Hubble Space Telescope ultraviolet spectra and supporting ground-based data for a sample of nine intermediate-mass T T Tauri stars (IMTTSs; 1.5-4 M⊙).
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Emission-Line Diagnostics of T Tauri Magnetospheric Accretion. II. Improved Model Tests and Insights into Accretion Physics
TL;DR: In this article, the authors present radiative transfer models of magnetospheric accretion in T Tauri stars, including line damping and continuum opacity, for a grid of models spanning a large range of magnetic geometries, and gas temperatures.
520
Accretion in brown dwarfs: An infrared view
TL;DR: In this article, a study of the accretion properties of 19 very low mass objects (M*∼0.01-0.1M ○ ) in the regions Chamaeleon I and p Oph is presented.
References
Magnetocentrifugally driven flows from young stars and disks. 1: A generalized model
TL;DR: In this paper, a generalized model for stellar spin-down, disk accretion, and truncation, and the origin of winds, jets, and bipolar outflows from young stellar objects is proposed.
1.4K
Accretion by rotating magnetic neutron stars. III. Accretion torques and period changes in pulsating X-ray sources.
Pranab Ghosh,F. K. Lamb +1 more
TL;DR: In this article, the solutions of the two-dimensional hydromagnetic equations are used to calculate the torque on a magnetic neutron star accreting from a Keplerian disk, revealing that the magnetic coupling between the star and the plasma in the outer transition zone is appreciable; as a result, the spin-up torque on fast rotators is substantially less than that on slow rotators, and that for sufficiently high stellar angular velocities or sufficiently low mass accretion rates, the rotation of the star can be braked while accretion continues.
1.1K
Disk accretion onto magnetic T Tauri stars
TL;DR: In this article, the dynamical and radiative consequences of disk accretion onto magnetic T T Tauri stars (TTS) were examined using the Ghosh and Lamb model, and it was shown that a prolonged disk accuration phase is compatible with the low rotation rates measured in these stars if they possess a kilogauss strength field that disrupts the disk at a distance of a few stellar radii from the center.
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