The gas disk around DM Tau
We present thermochemical models of the density and temperature struture of the disk around the transition object, DM Tau. DM Tau is an accreting, low mass T Tauri star with a relatively low X-ray luminosity, the disk is inferred to have an inner $\sim 3-15$AU dust hole and a large radial extent($\sim$ 800 AU). The DM Tau disk is believed to be at a late stage of evolution, perhaps with ongoing planet formation. We have compiled gas emission line observations from literature, ranging from optical to sub-millimeter wavelengths, and modeled the line emission to infer the physical and chemical conditions in the disk.