ABSTRACT. Using the Submillimeter Array (SMA), we have imaged the 1.3 mm continuum emission at the centers of the massive star-forming regions NGC 6334 I and I(N). In both regions, the SMA observations resolve the emission into multiple millimeter sources, with most of the sources clustered into areas only 10,000 AU in diameter. Toward NGC 6334 I, we find four compact sources: the two brightest (I-SMA1 and I-SMA2) are associated with previously known ammonia cores; I-SMA3 coincides with the peak of the compact H II region (NGC 6334 F), and I-SMA4 is a newly discovered object. While I-SMA3 exhibits a mixture of free-free and dust emission, the rest of the objects are dust cores. Toward NGC 6334 I(N), seven compact dust cores are found, one of which is associated with a faint centimeter source. With the exception of I-SMA3, none of the millimeter sources have infrared counterparts in Spitzer Space Telescope 3-8 μm images. Using a simple physical model for the dust continuum emission, we estimate that the mass of the interstellar material toward each of these compact objects is in the range of 3-66 M. The total mass in the compact objects appears to be similar in I and I(N). The small size of these groups of sources suggest that these objects are proto-Trapezia forming in the centers of clusters of low- to intermediate-mass stars.

Subject headings: infrared: stars; ISM: individual (NGC 6334, NGC 6334 I(N)); stars: formation; submillimeter; techniques: interferometric

Print publication: Issue 2 (2006 October 1)
Received 2006 March 2, accepted for publication 2006 May 17