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Description
The far-ultraviolet (FUV; 912-1700 {AA}) radiation field from accreting central stars in classical T Tauri systems influences the disk chemistry during the period of giant planet formation. The FUV field may also play a critical role in determining the evolution of the inner disk (r<10 AU), from a gas- and dust-rich primordial disk to a transitional system where the optically thick warm dust distribution has been depleted. Previous efforts to measure the true stellar+accretion-generated FUV luminosity (both hot gas emission lines and continua) have been complicated by a combination of low-sensitivity and/or low-spectral resolution and did not include the contribution from the bright Ly{alpha} emission line. In this work, we present a high-resolution spectroscopic study of the FUV radiation fields of 16 T Tauri stars whose dust disks display a range of evolutionary states. We include reconstructed Ly{alpha} line profiles and remove atomic and molecular disk emission (from H_2_ and CO fluorescence) to provide robust measurements of both the FUV continuum and hot gas lines (e.g., Ly{alpha}, N V, C IV, He II) for an appreciable sample of T Tauri stars for the first time. We find that the flux of the typical classical T Tauri star FUV radiation field at 1 AU from the central star is ~10^7^ times the average interstellar radiation field. The Ly{alpha} emission line contributes an average of 88% of the total FUV flux, with the FUV continuum accounting for an average of 8%. Both the FUV continuum and Ly{alpha} flux are strongly correlated with C IV flux, suggesting that accretion processes dominate the production of both of these components. On average, only ~0.5% of the total FUV flux is emitted between the Lyman limit (912 {AA}) and the H_2_(0-0) absorption band at 1110 {AA}. The total and component-level high-resolution radiation fields are made publicly available in machine-readable format.
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