THE DISKS OF T-TAURI STARS WITH FLAT INFRARED-SPECTRA

[[abstract]]The authors model the energy distributions of T Tauri stars with flat infrared spectra by assuming that they have spatially thin disks with unorthodox radial gradients of temperature. These sources differ from more common T Tauri stars in that the extreme shallowness of their spectral slope cannot be plausibly explained by conventinal ideas (e.g., Keplerian accretion or reprocessing of starlight by a slightly flared disk). Derived model parameters show that the disks associated with the flat-spectrum sources must contain intrinsic luminosity in addition to the energy intercepted and reprocessed from the central star; i.e., the disks must be active. Self-gravity may provide one possible source for this activity - the spectral limits and estimates of the disk masses derived for three systems (T Tau, DG Tau, and HL Tau) are close to the theoretical values that would make the self-gravity of the disks dynamically important. --------------------------------------------------------------------------------[[fileno]]2010118010083[[department]]物理