Star formation in the Magellanic Clouds - IV. Protostars in the vicinity of 30 Doradus

From a magnitude-limited infrared survey of the 30 Doradus complex we have identified four candidate protostars. These are associated with dense knots in the nebular arcs, and have luminosities of 1-5 x 10⁴ L_o and masses of 15-20 M_o. The results indicate that both the knots and the associated star formation are likely to be caused by the compression of interacting arcs of mass-loss winds from hot massive stars in the central cluster, and other nearby clusters. This mode of star formation differs from the classical star formation scenario within dense molecular clouds, and appears to be highly efficient. Our new data confirm the spatial separation of the young blue and older red stars, and provide further evidence for a multiple-starburst origin for the 30 Doradus region. The qualitative similarity of the structure of the central cluster to the structure of the LMC blue globulars has been noted previously. In this paper we use the brightness distribution and number counts to investigate the structure quantitatively, following the approach of Elson, Fall & Freeman for blue globular clusters.