{"references": ["Arulanantham, N. et al. (2021) UV Fluorescence Traces Gas and Ly\u03b1 Evolution in Protoplanetary Disks", "Manara, C. F. et al. (2021) PENELLOPE: The ESO data legacy program to complement the Hubble UV Legacy Library of Young Stars (ULLYSES). I. Survey presentation and accretion properties of Orion OB1 and \u03c3-Orionis", "Gronke, M. et al. (2016) From Mirrors to Windows: Lyman-alpha Radiative Transfer in a Very Clumpy Medium", "McJunkin, M. et al. (2014) Direct Measurement of Interstellar Extinction toward Young Stars Using Atomic Hydrogen Ly\u03b1 Absorption", "Fiorellino, E. et al. (2022) The Accretion Process in the DQ Tau Binary System", "France, K. et al. (2014) High-resolution Ultraviolet Radiation Fields of Classical T Tauri Stars", "Bergin, E. et al. (2003) The Effects of UV Continuum and Ly\u03b1 Radiation on the Chemical Equilibrium of T Tauri Disks", "Heays, A. et al. (2017) Photodissociation and photoionisation of atoms and molecules of astrophysical interest"]}

T Tauri systems, the young precursors to Sun-like stars, produce broad LyA emission lines (FWHM = 500-700 km/s). The LyA photons are generated at the accretion shocks and must travel through an outflowing wind, protoplanetary disk, and the ISM before reaching the observer. This produces asymmetric features, with the blue or red sides absorbed by outflowing or infalling H I. The ratios of red to blue flux are correlated with properties of the protoplanetary disks, indicating that disk and wind evolution are linked (Arulanantham et al. 2021). By fitting accurate models to the LyA emission lines, we can quantify the kinematics at the intersection between the inner disks, wind launching regions, and accretion flows.