Line-of-Sight Extinction Toward T Tauri Stars

We present medium resolution (RP ∼2500) spectra for several young T-Tauri stars in the near-IR region between 0.8 and 5 μ m acquired with the SpeX spectrometer at NASA's Infrared Telescope Facility. The spectra are rich in H I recombination lines. We report the fluxes of the emission lines in the Paschen and Brackett series and compare the relative line strengths with predicted theoretical values to estimate line-of-sight extinction. We explore the suppression of fluxes for lower n lines in the series due to opacity and the resulting implications upon extinction calculations.

This work was supported by the Research Experience for Undergraduates Program and NSF grant AST 02-05881.