THE CIRCUMSTELLAR DISK MASS DISTRIBUTION IN THE ORION TRAPEZIUM CLUSTER

We present the results of a submillimeter interferometric survey of circumstellar disks in the Trapezium cluster of Orion. We observed the 880 μm continuum emission from 55 disks using the Submillimeter Array,1The Submillimeter Array is a joint project between the Submillimeter Astrophysical Observatory and the Academica Sinica Institute of Astronomy and Astrophysics and is funded by the Smithsonian Institution and the Academica Sinica. and detected 28 disks above 3σ significance with fluxes between 6 and 70 mJy and rms noise between 0.7 and 5.3 mJy. Dust masses and upper limits are derived from the submillimeter excess above free-free emission extrapolated from longer wavelength observations. Above our completeness limit of 0.0084 M sun, the disk mass distribution is similar to that of Class II disks in Taurus-Auriga and ρ Ophiuchus but is truncated at 0.04 M sun. We show that the disk mass and radius distributions are consistent with the formation of Trapezium cluster disks ∼1 Myr ago and subsequent photoevaporation by the ultraviolet radiation field from θ1 Ori C. The fraction of disks that contain a minimum mass solar nebula within 60 AU radius is estimated to be 11%-13% in both Taurus and the Trapezium cluster, which suggests the potential for forming Solar Systems is not compromised in this massive star-forming region.