Hard X‐Rays and Fluorescent Iron Emission from the Embedded Infrared Cluster in NGC 2071

We present first results of XMM-Newton X-ray observations of the infraredcluster lying near the NGC 2071 reflection nebula in the Orion B region. Thiscluster is of interest because it is one of the closest regions known to harborembedded high-mass stars. We report the discovery of hard X-ray emission fromthe dense central NGC 2071-IR subgroup which contains at least three high-massyoung stellar objects (NGC 2071 IRS-1, IRS-2, and IRS-3). A prominent X-raysource is detected within 1 arcsecond of the infrared source IRS-1, which isthought to drive a powerful bipolar molecular outflow. The X-ray spectrum ofthis source is quite unusual compared to the optically thin plasma spectranormally observed in young stellar objects (YSOs). The spectrum ischaracterized by a hard broad-band continuum plus an exceptionally broademission line at approximately 6.4 keV from neutral or near-neutral iron. Thefluorescent Fe line likely originates in cold material near the embedded star(i.e. a disk or envelope) that is irradiated by the hard heavily-absorbed X-raysource.Comment: To appear in ApJ (8 pages, 7 figures