Collapse of Magnetized Singular Isothermal Toroids. I. The Nonrotating Case

We present a high-resolution study of NGC 2264 IRS 1 in CS 2 -1 and in the 3 mm continuum using the IRAM Plateau de Bure interferometer. We complement these radio data with images taken at 2.2, 4.6, and 11.9 (mu)m. The combined information allows a new interpretation of the closest environment of NGC 2264 IRS 1. No disk around the B-type star IRS 1 was found. IRS 1 and its low-mass companions are located in a low-density cavity that is surrounded by the remaining dense cloud core that has a clumpy, shell-like structure. Strong evidence for induced ongoing star formation was found in the surroundings of IRS 1. A deeply embedded very young stellar object 20" to the north of IRS 1 is powering a highly collimated bipolar outflow. Object 8 in the closer environment of IRS 1 is a binary surrounded by dusty circumbinary material and powering two bipolar outflows.