Primordial circumstellar disks in binary systems

This allows us to construct a sample of 349 targets, including 125 binaries, which we use to to investigate the effect of companions on the evolution of circumstellar disks. We find that the distribution of projected separations of systems with Spitzer excesses is significantly different (P~2.4e-5, according to the K-S test for binaries with separations less than 400AU) from that of systems lacking evidence for a disk.

As expected, systems with projected separations less than 40AU are half as likely to retain at least one disk than are systems with projected separations in the 40-400AU range. These results represent the first statistically significant evidence for a correlation between binary separation and the presence of an inner disk (r~1AU). Several factors (e.g., the incompleteness of the census of close binaries, the use of unresolved disk indicators, and projection effects) have previously masked this correlation in smaller samples.