High-resolution millimeter imaging of the R Coronae Australis IRS 7 region

The R CrA IRS 7 region was observed in the lambda = 6.9 mm continuum with a high angular resolution (similar to1"). The map shows three compact objects located within 4" (700 AU) of IRS 7A. Since the object in the middle of the complex has no known counterpart at centimeter wavelengths, its millimeter emission may mostly come from dust, suggesting that it may be a deeply embedded object. In contrast, IRS 7A is probably not as deeply embedded as the others since it was detected in near-IR and X-ray bands. It is not clear what causes the difference between IRS 7A and the others. If they belong to a coeval triple stellar system, either IRS 7A may have evolved faster and disrupted the parent cloud faster than the others or it may be in the process of being ejected. Alternatively, IRS 7A could be a relatively older object in the process of being captured by the other two objects that constitute a younger binary system. Yet another possibility is that IRS 7A may not be a young stellar object but may be a part of the outflow driven by the central object of the complex. The identity of the hard X-ray flare source previously found in this field needs to be clarified by further observations.