|
The properties of the midplanes of planet-forming protostellar disks remain largely unprobed by observations due to the high optical depth of dust and commonly observed molecules. However, rotational emission lines from rare molecules may have optical depths near unity in the vertical direction, so that the lines are strong enough to be detected, yet remain transparent enough to trace the disk midplane. In this talk, I will present a chemical evolution model of an MRI-active T-Tauri disk. The optical depths of low-order rotational lines of C17O are around unity, which suggests it may be possible to see into the disk midplane using C17O. With our computed C17O/H2 abundance ratio, such ALMA observations would provide estimates of the disk masses by measuring the intensity of gas emission. |
|