Impacts of energetic particles from T Tauri flares on inner protoplanetary discs
Abstract
T Tauri stars are known to be magnetically active stars subject to strong flares observed in X-rays. These flares are likely due to intense magnetic reconnection events during which a part of the stored magnetic energy is converted into kinetic energy of supra-thermal particles. Since T Tauri stars are surrounded by an accretion disc, these particles may influence the disc dynamics and chemistry. This work continues on a previous stationary model, which showed that energetic particles accelerated during flares can produce a strong ionization rate at high column densities in the inner accretion disc. The present model includes non-stationary sequences of flaring events sampled by a Chandra X-ray survey of nearby young stellar objects. We calculate the averaged ionization rate expected in a radius range 0.08-0.6 au from the central star. We confirm that energetic particles produced by the flares dominate the ionization of the disc up to column densities of $10^{25}~\rm {cm^{-2}}$. We further study the main consequences of this additional source of ionization on the viscosity, the accretion rate, the volumetric heating rate, and the chemical complexity of inner protoplanetary discs.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- June 2024
- DOI:
- arXiv:
- arXiv:2404.16459
- Bibcode:
- 2024MNRAS.530.3669B
- Keywords:
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- acceleration of particles;
- accretion;
- accretion discs;
- magnetic reconnection;
- stars: flare;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 20 pages, 17 figures