Unveiling the Circumstellar Envelope and Disk: A Subarcsecond Survey of Circumstellar Structures

Abstract

We present the results of a λ=2.7 mm continuum interferometric survey of 24 young stellar objects in 11 fields. The target objects range from deeply embedded class 0 sources to optical T Tauri sources. This is the first subarcsecond survey of the λ=2.7 mm dust continuum emission from young, embedded stellar systems. These multiarray observations, utilizing the high dynamic u-v range of the BIMA array, fully sample spatial scales ranging from 0.4" to 60", thus allowing the first consistent comparison of dust emission structures in a variety of systems. The images show a diversity of structure and complexity. The optically visible T Tauri stars (DG Tauri, HL Tauri, GG Tauri, and GM Aurigae) have continuum emission dominated by compact ( =85% of the emission at λ=2.7 mm. In many of the deeply embedded systems, it is difficult to uniquely isolate the disk emission component from the envelope extending inward to AU-sized scales. Simple estimates of the circumstellar mass in the optical/infrared and embedded systems are in the ranges 0.01-0.08 Msolar and 0.04-2.88 Msolar, respectively. All of the target embedded objects are in multiple systems with separations on scales of ~30" or less. Based on the system separation, we place the objects in three categories: separate envelope (separation >=6500 AU), common envelope (separation 150-3000 AU), and common disk (separation