title: CO(6-5) And C I (2-1) Pointed Observations Of 5 Haebe Disks

authors: A. Hales, S. Casassus, B. Dent, A. Belloche, F. Menard, M. Hughes, D. Wilner

abstract: The short dispersal timescales of the planet-forming gas in disks hampers its detection.  Although ro-vibrational CO is observed in HAeBe disks, CO(3-2) is less frequent, and is often contaminated by diffuse emission in single-dish data. CO(6-5) traces gas at intermediate temperatures between the cold molecular gas that originates CO(3-2), and the hotter inner-rim gas seen in the IR ro-vibrational lines. Neutral carbon, C I (2-1), is a tracer of the atomic phase in disks. No C I (2-1) detections in disks exist in the literature.

As a followup to a CO(3-2) survey in protoplanetary disks, we acquired CHAMP+ maps in CO(6-5) 691.4 GHz and C I(2-1)809 GHz. Our objectives are to identify new gas-rich systems for ALMA observations of sub-mm high-J CO, and search for C I. We obtained interesting upper limits in four targets and one CO(6-5) detection in HD142527.  No neutral carbon was detected. In this poster we present our main results, and discuss their implications.