I am principal investigator of a Chandra X-ray Observatory legacy project to survey the the Cygnus OB2 Association and use it as a laboratory for understanding massive star formation, the influence of massive stars on lower mass star and planet formation, and the high energy astrophysics of young stellar objects. Studies of our Galaxy's super-cluster candidates is generally hampered by their great distances (Arches at 10 kpc, W49 at 12 kpc, NGC 3603 at 6 kpc. Westerlund 1 at 5.5 kpc). There is just one exception. In the last few years realization has grown that Cygnus OB2 (D = 1.5 kpc), the pre-eminent cluster and central engine of the massive molecular-gas dominated Cygnus X region approaches supercluster dimensions. With an age of 2-5 Myr, it has been estimated to contain about 2000 OB stars, of which as many as 100 may be O-type stars. Cygnus OB2 belongs to the elite club of massive clusters in hosting two O3 stars, of which only ~10 Galactic examples are known. Cygnus OB2 is therefore among the most extreme OB associations in our Galaxy. It is potentially dense and massive enough to stand comparison with globular clusters and the superclusters that characterize starbursts. The Chandra survey - comprising slightly more than 1 million seconds of exposure time - will locate all the "low-mass" (from 2-3 solar masses and below) stars, allowing a comprehensive census of the stellar population, the protoplanetary disk fractions in different UV radiation environments, the cluster dynamics, and the X-ray properties of the cluster stars and diffuse gas. |
Current projects >