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Full-Text Articles in Physical Sciences and Mathematics
Interpreting Near Infrared Hydrogen Line Ratios In T Tauri Stars, Suzan Edwards
Interpreting Near Infrared Hydrogen Line Ratios In T Tauri Stars, Suzan Edwards
Astronomy: Faculty Publications
In accreting young stars, one of the prominent spectral features in the near-infrared is the Paschen and Brackett series in emission. We examine hydrogen line ratios for 16 classical T Tauri stars from SpeX spectra and assess the trends with veiling and accretion. The observed line ratios are compared with two theoretical models for line formation: (1) Baker & Menzel’s Case B for radiative ionization and recombination and (2) a set of local line excitation calculations designed to replicate the conditions in T Tauri winds and magnetic accretion columns (KF). While the comparison between Case B and observed line ratios …
Hot Gas Lines In T Tauri Stars, David R. Ardila, Gregory J. Herczeg, Scott G. Gregory, Laura Ingleby, Kevin France, Alexander Brown, Suzan Edwards, Christopher Johns-Krull, Jeffrey L. Linsky, Hao Yang, Jeff A. Valenti, Hervé Abgrall, Richard D. Alexander, Edwin Bergin, Thomas Bethell, Joanna M. Brown, Nuria Calvet, Catherine Espaillat, Lynne A. Hillenbrand, Gaitee Hussain, Evelyne Roueff, Eric R. Schindhelm, Frederick M. Walter
Hot Gas Lines In T Tauri Stars, David R. Ardila, Gregory J. Herczeg, Scott G. Gregory, Laura Ingleby, Kevin France, Alexander Brown, Suzan Edwards, Christopher Johns-Krull, Jeffrey L. Linsky, Hao Yang, Jeff A. Valenti, Hervé Abgrall, Richard D. Alexander, Edwin Bergin, Thomas Bethell, Joanna M. Brown, Nuria Calvet, Catherine Espaillat, Lynne A. Hillenbrand, Gaitee Hussain, Evelyne Roueff, Eric R. Schindhelm, Frederick M. Walter
Astronomy: Faculty Publications
For Classical T Tauri Stars (CTTSs), the resonance doublets of N v, Si iv, and Civ, as well as the He ii 1640 Å line, trace hot gas flows and act as diagnostics of the accretion process. In this paper we assemble a large high-resolution, high-sensitivity data set of these lines in CTTSs and Weak T Tauri Stars (WTTSs). The sample comprises 35 stars: 1 Herbig Ae star, 28 CTTSs, and 6 WTTSs. We find that the Civ, Si iv, and N v lines in CTTSs all have similar shapes. We decompose the Civ and He ii lines into broad …