Mid?Infrared Observations of T Tauri Stars: Probing the Star?Disk Connection in Rotational Evolution

We present mid-IR N-band $(\lambda_{eff} = 10.2\micron)$ photometry of acarefully selected sample of T Tauri stars thought to be single from theTaurus-Auriga molecular cloud. Infrared excesses in these stars are generallyattributed to circumstellar dust-disks. Combining observations at 2.16$\micron$(K$_{s}$-band) and 10.2$\micron$ (N-band) we probe a region in thecircumstellar dust-disk from a few stellar radii through the terrestrial planetzone (0.02-1.0AU). By analyzing the distribution of the $(K_{s}-N)$ color indexwith respect to previously measured photometric rotation periods we investigatewhat role circumstellar disks play in the rotational evolution of the centralstar. The resulting positive correlation between these two variables isconsistent with the notion that a star-disk interaction facilitates theregulation of angular momentum during the T Tauri stage. We also demonstrate,how including non-single stars in such an analysis will \textit{weaken} anycorrelation in the relation between $(K_{s}-N)$ color and period. To furtherunderstand disk properties we also present SEDs for a few objects with newground based M-band $(\lambda_{eff} = 4.8\micron)$ and Q-band $(\lambda_{eff} =20\micron)$ data and compare them to a geometrically thin, optically-thick diskmodel.Comment: 9 pages, 4 figure