Mid-infrared observations of T Tauri stars: probing the star-disk connection in rotational evolution.
KUNDURTHY P., MEYER M.R., ROBBERTO M., BECKWITH S.V.W. and HERBST T.
Abstract (from CDS):
We present mid-IR N-band (λeff=10.2 µm) photometry of a carefully selected sample of T Tauri stars thought to be single from the Taurus-Auriga molecular cloud. Infrared excesses in these stars are generally attributed to circumstellar dust disks. Combining observations at 2.16 (Ks band) and 10.2 µm (N band) we probe a region in the circumstellar dust disk from a few stellar radii through the terrestrial planet zone (0.02-1.0 AU). By analyzing the distribution of the (Ks-N) color index with respect to previously measured photometric rotation periods we investigate what role circumstellar disks play in the rotational evolution of the central star. The resulting positive correlation between these two variables is consistent with the notion that a star-disk interaction facilitates the regulation of angular momentum during the T Tauri stage. We also demonstrate how including nonsingle stars in such an analysis weakens any correlation in the relation between (Ks-N) color and period. To further understand disk properties we also present spectral energy distributions for a few objects with new ground-based M-band (λeff=4.8 µm) and Q-band (λeff=20 µm) data and compare them to a geometrically thin, optically thick disk model.