Tracing molecular gas in protoplanetary disks: measuring 12CO and 13CO emission from disks around nearby young stars

Coordinator: A. Carmona, M.E. van der Ancker

We propose to search for 12CO(J=3-2) emission at 345.86 GHz and 13CO(J=3-2) emission at 330.59 GHz in a sample of well known nearby Herbig Ae/Be and T Tauri stars using APEX. The measurement of these emission lines will allow us to determine the amount of CO in the outer disk (R>50AU). Models of typical passive flared disks will be used to fit the shape of the CO emission lines and to constrain basic parameters as size, inclination and rotational dynamics. These observations, combined with H2 measurments in the mid-IR, will also permit us to test how well CO traces the H2 in the studied disks.

Program is available and data products can be downloaded

Scientific Rationale

Giant planets in our solar system and the extrasolar planets detected so far are mostly composed of gas. They are believed to hove formed from a vast reservoir of molecular hydrogen in the circumstellar disk that surrounded their host star during the pre-main sequenece phase. Two key questions regarding the gas in these protoplanetarydisks remain largely unanswered: (1) how long does the gageous disk last?, and (2) how massive is the initial disk?.