Measuring the density structure of an accretion hot spot

  title={Measuring the density structure of an accretion hot spot},
  author={Catherine C. Espaillat and Connor E. Robinson and Marina M. Romanova and T Thanathibodee and John Wendeborn and Nuria Calvet and Mark T. Reynolds and J Muzerolle},
  pages={41 - 44}
Magnetospheric accretion models predict that matter from protoplanetary disks accretes onto stars via funnel flows, which follow stellar magnetic field lines and shock on the stellar surfaces1–3, leaving hot spots with density gradients4–6. Previous work has provided observational evidence of varying density in hot spots7, but these observations were not sensitive to the radial density distribution. Attempts have been made to measure this distribution using X-ray observations8–10; however, X… 
Testing the Potential for Radio Variability in Disks around T Tauri Stars with Observations and Chemical Modeling
A multiwavelength observing campaign of the T Tauri star (TTS) GM Aur was undertaken in 2019 December. This campaign obtained Swift X-ray and NUV fluxes, HST NUV spectra, LCOGT u′ g′ r′ i′ and TESS


A measure of the size of the magnetospheric accretion region in TW Hydrae
  • R. A. A. T. P. R. M. L. K. J. M. C. L. W. P. J. V. Th Garcia Lopez Natta Caratti o Garatti Ray Fedriani , R. Garcia Lopez, +70 authors G. Zins
  • Physics, Medicine
  • 2020
The size of the inner disk of the T Tauri star TW Hydrae is determined using optical long-baseline interferometric observations, indicating that hydrogen emission originates in the accretion columns, as expected in magnetospheric accretion models, rather than in a wind emitted at much larger distance.
The Structure and Emission of the Accretion Shock in T Tauri Stars
We have examined one of the key predictions of the magnetospheric infall model for classical T Tauri stars (CTTS), namely, the formation of a shock on the stellar surface. We find that accretion
TW Hya: Spectral Variability, X-Rays, and Accretion Diagnostics
The nearest accreting T Tauri star, TW Hya was intensively and continuously observed over ~17 days with spectroscopic and photometric measurements from four continents simultaneous with a long
Multiepoch, multiwavelength study of accretion onto T Tauri
Classical T Tauri stars (CTTSs) accrete matter from the inner edge of their surrounding circumstellar disks. The impact of the accretion material on the stellar atmosphere results in a strong shock,
Magnetohydrodynamic modeling of the accretion shocks in classical T Tauri stars: the role of local absorption on the X-ray emission
We investigate the properties of X-ray emission from accretion shocks in classical T Tauri stars (CTTSs), generated where the infalling material impacts the stellar surface. Both observations and
Accretion onto Pre-Main-Sequence Stars
Accretion through circumstellar disks plays an important role in star formation and in establishing the properties of the regions in which planets form and migrate. The mechanisms by which
Accretion, Outflows, and Winds of Magnetized Stars
Many types of stars have strong magnetic fields that can dynamically influence the flow of circumstellar matter. In stars with accretion disks, the stellar magnetic field can truncate the inner disk
Probing the magnetospheric accretion region of the young pre-transitional disk system DoAr 44 using VLTI/GRAVITY
Young stellar objects are thought to accrete material from their circumstellar disks through their strong stellar magnetospheres. We aim to directly probe the magnetospheric accretion region on a
We analyze the accretion properties of 21 low-mass T Tauri stars using a data set of contemporaneous near-UV (NUV) through optical observations obtained with the Hubble Space Telescope Imaging
Accretion to magnetized stars through the Rayleigh–Taylor instability: global 3D simulations
We present results of 3D simulations of magnetohydrodynamics (MHD) instabilities at the accretion disc‐magnetosphere boundary. The instability is Rayleigh‐Taylor, and develops for a fairly broad