Constraints to the magnetospheric properties of T Tauri stars. I. The C II], Fe II] and Si II] ultraviolet features
arXiv:1405.7180 · doi:10.1093/mnras/stu1045
Abstract
The C II] feature at ~2325 Angstrom is very prominent in the spectra of T Tauri stars (TTSs). This feature is a quintuplet of semiforbidden transitions excited at electron temperatures around 10,000 K that, together with the nearby Si II] and Fe II] features, provides a reliable optically thin tracer for accurate measurement of the plasma properties in the magnetospheres of TTSs. The spectra of 20 (out of 27) TTSs observed with the Space Telescope Imaging Spectrograph (STIS) on board the Hubble Space Telescope (HST) have good enough signal to noise ratio (S/N) at the C II] wavelength. For these stars we have determined electron densities (ne) and temperatures (Te) in the line emission region as well as the profile broadening (sigma). For most of the stars in the sample (17) we obtain 10^{4.1} < Te < 10^{4.5} K and 10^{8} < ne < 10^{12} cm^{-3}. These stars have suprathermal line broadening (35 < sigma < 165 km s^{-1}), except TW Hya and CY Tau with thermal line broadening. Both C II] line luminosity and broadening are found to correlate with the accretion rate. Line emission seems to be produced in the magnetospheric accretion flow, close to the disk. There are three exceptions: DG Tau, RY Tau and FU Ori. The line centroids are blueshifted indicating that the line emission in these three stars is dominated by the outflow.
arXiv comment13 pages, 15 figures, published in MNRAS minor changes
References in corpus (30)
- Resolved Images of Large Cavities in Protoplanetary Transition Disks
- Observational Constraints on the Formation and Evolution of Binary Stars
- A Survey and Analysis of Spitzer Infrared Spectrograph Spectra of T Tauri Stars in Taurus
- Unveiling the Structure of Pre-Transitional Disks
- Accretion Rates for T Tauri Stars Using Nearly Simultaneous Ultraviolet and Optical Spectra
- Ultraviolet Extinction Properties in the Milky Way
- Close Companions to Young Stars. I. A Large Spectroscopic Survey in Chamaeleon I and Taurus-Auriga
- Search for associations containing young stars. III- Ages and Li abundances
- A VLT/NACO Survey for Triple and Quadruple Systems among Visual Pre-Main Sequence Binaries
- Accretion Disks around Young Stars: Lifetimes, Disk Locking and Variability
- Measuring Protoplanetary Disk Accretion with H I Pf-beta
- A Far-ultraviolet Atlas of Low-resolution Hubble Space Telescope Spectra of T Tauri Stars
- Pre-main sequence spectroscopic binaries suitable for VLTI observations
- A Hubble Space Telescope Survey of H2 Emission in the Circumstellar Environments of Young Stars
- Spectral variability of classical T Tauri stars accreting in an unstable regime
- T Tauri Jet Physics Resolved Near The Launching Region with the Hubble Space Telescope
- Hot Gas Lines in T Tauri Stars
- The Origins of Fluorescent H2 Emission From T Tauri~Stars
- Analytical Hot Spot Shapes and Magnetospheric Radius from 3D Simulations of Magnetospheric Accretion
- Observations of T-Tauri Stars using HST-GHRS: I. Far Ultraviolet Emission Lines
- The unusual protoplanetary disk around the T Tauri star ET Cha
- Magnetocentrifugally Driven Flows from Young Stars and Disks. VI. Accretion with a Multipole Stellar Field
- Herschel/PACS Survey of protoplanetary disks in Taurus/Auriga -- Observations of [OI] and [CII], and far infrared continuum
- FU Orionis: A Binary Star?
- Evolution of X-ray and FUV Disk-Dispersing Radiation Fields
- Quiescent H2 Emission From Pre-Main Sequence Stars in Chamaeleon I
- Constraints on the disk geometry of the T Tauri star AA Tau from linear polarimetry
- Evidence for stellar driven outflows from the Classical T Tauri star RY Tau
- Line Structure in the Spectrum of FU Orionis
- Evidence of hot high velocity photoionized plasma falling on actively accreting T-Tauri Stars
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- Wind Dynamics and Circumstellar Extinction Variations in the T Tauri Star RY Tau
- On the source of the Fe K-alpha emission in T Tauri Stars. Radiation induced by relativistic electrons during flares. An application to RY Tau