SIMBAD references

We present a bispectrum speckle interferometry study of the embedded young stellar objects in Mon R2 IRS3 in the near-infrared H and K bands. Our images with a resolution of 75mas (=62AU) show a close triple system surrounded by strong diffuse nebulosity and three additional infrared sources (K magnitudes ∼11.8-13.7) within 3'' of the brightest object IRS3 A (K∼7.9). We use HST/NICMOS archive images to derive near-infrared photometry for the sources and estimate the stellar masses of the three brightest objects IRS3 A, B, and C to be in the range ∼5-15M_☉. IRS3 A is surrounded by a bipolar nebula (position angle ∼30°), suggesting it to be embedded in a thick circumstellar disk or a torus with polar cavities. IRS3 B shows a remarkable jet-like emission feature pointing towards the north-east (position angle 50°). This feature consists of at least three individual knots with projected separations of 130, 230, and 290mas (110, 190, and 240 AU) from IRS3 B, which are much brighter in the K band than in the H band. This strongly indicates outflow activity from IRS3 B, which is therefore probably the source of the compact high velocity molecular outflow reported from Mon R2 IRS3. We also analyze Chandra X-ray archive data for the Mon R2 region and find IRS3 A and IRS3 C to be sources of hard (3-10keV) and variable X-ray emission, suggesting plasma temperatures of at least 50x10⁶K. The similarity of the X-ray properties to those of Class I protostars suggests magnetic interaction between the protostars and their circumstellar disks to be the origin of the X-ray emission; this provides indirect evidence for the presence of circumstellar disks in the intermediate- to high-mass young stellar objects IRS3 A and IRS3 C.