Rings of C2H in the Molecular Disks Orbiting TW Hya and V4046 Sgr. Issue Volume 10:Issue S314(2015) (November 2015) - Kastner, J. H.
Abstract: We have used the Submillimeter Array (SMA) to image, at ~1″ resolution, C2 H(3−2) emission from the molecule-rich circumstellar disks orbiting the nearby, classical T Tauri star systems TW Hya and V4046 Sgr. The SMA imaging reveals that the C2 H emission exhibits a ring-like morphology within each disk; the radius of the inner hole of the C2 H ring within the V4046 Sgr disk (~70 AU) is somewhat larger than than of its counterpart within the TW Hya disk (~45 AU). We suggest that, in each case, the C2 H emission likely traces irradiation of the tenuous surface layers of the outer disks by high-energy photons from the central stars.