Title: "Deep L'-band Photometry of Substellar Objects around a Massive Star in S106"
Author(s): Munechika Tanaka, Yumiko Oasa, Yoichi Itoh

Abstract:

Substellar objects may form from a contracting cloud just like low-mass stars, or removal of accretion envelopes from low mass contracting cores due to photo-evaporation due to a nearby O-type star. Otherwise they may be dynamically ejected from an unstable multiple protostellar system. Substellar objects around a massive star are studied only toward the Trapezium cluster, and it is still unknown how young substellar mass objects form, which are exposed to the UV radiation from massive stars. To obtain constraints on their formation process, it is essential to examine the distribution around a massive star.
We executed a deep JHKL photometric survey in S106, which is one of the nearest massive star forming region. A massive star IRS4 (O9V) is located at the center of the S106 region. By this survey more than two hundreds young stellar objects (YSOs), including dozens of substellar YSOs, are identified. The distribution of the YSOs indicates that the central O-star IRS4 does not evaporate the disks around nearby low-mass YSOs. We also found two regions characterized by very high fractions of the Class I sources.