Debris disks with CO detections. The disk’s CO mass and inclination are used to determine the ideal candidates (green area); from our simulations, if the disk is too massive (i.e., luminous), the emission in the gap is too big, similar to the protoplanetary disk regime. On the other hand, if the disk is too light, it is not luminous enough to be observed at a high resolution. Moreover, a too inclined disk prevents a clear detection of the gap.