Disks in CO at near-infrared

seeing gas at the disk inner rim

The picture in the left hand side is a 2D spectra of HD 141569, a Herbig Ae star, at 4.6 um. The CO v=2-1 lines are seen in the overlap with the stellar continuum emission (second column). After subtracting the stellar continuum, the CO line emission looks exteded up to 50 AU to the both of the sidde, with unmistakable signature of disk rotation. The sixe of the central clearing is measured to be 11 AU, which is consistent with the photo-evaporation of the gas in the inner disk, that creates a hole of the size of about the gravitational radius of a star.