We present high-resolution, near-infrared NIRSPEC observations of CO absorption toward six class II T Tauri stars: AA Tau, DG Tau, IQ Tau, RY Tau, CW Tau, and Haro 6-5b. 12CO overtone absorption lines originating from the circumstellar disk of each object were used to calculate line-of-sight gas column densities toward each source. We measured the gas/dust ratio as a function of disk inclination, utilizing measured visual extinctions and inclinations for each star. The majority of our sources show further evidence for a correlation between the gas/dust column density ratio and disk inclination similar to that found by Rettig et al.
The Astrophysical Journal
Horne, David; Gibb, Erika; Rettig, Terrence; Brittain, Sean; Tilley, David; and Balsara, Dinshaw, "The Gas/Dust Ratio of Circumstellar Disks: Testing Models of Planetesimal Formation" (2012). Physics Faculty Works. 15.
Available at: https://irl.umsl.edu/physics-faculty/15