Investigating the nature of the extended structure around the Herbig
  star RCrA using integral field and high-resolution spectroscopy
  We present a detailed analysis of the extended structure detected around the
young and close-by Herbig Ae/Be star RCrA. This is a young triple system with
an intermediate mass central binary whose separation is of the order of a few
tens of the radii of the individual components, and an M-star companion at
about 30 au. Our aim is to understand the nature of the extended structure by
means of combining integral-field and high-resolution spectroscopy. We
conducted the analysis based on FEROS archival optical spectroscopy data and
adaptive optics images and integral-field spectra obtained with SINFONI and
SPHERE at the VLT. The observations reveal a complex extended structure that is
composed of at least two components: a non-uniform wide cavity whose walls are
detected in continuum emission up to 400~au, and a collimated wiggling-jet
detected in the emission lines of Helium and Hydrogen. Moreover, the presence
of [FeII] emission projected close to the cavity walls suggests the presence of
a slower moving wind, most likely a disk wind. The multiple components of the
optical forbidden lines also indicate the presence of a high-velocity jet
co-existing with a slow wind. We constructed a geometrical model of the
collimated jet flowing within the cavity using intensity and velocity maps,
finding that its wiggling is consistent with the orbital period of the central
binary. The cavity and the jet do not share the same position angle, suggesting
that the jet is itself experiencing a precession motion possibly due to the
wide M-dwarf companion. We propose a scenario that closely agrees with the
general expectation of a magneto-centrifugal-launched jet. These results build
upon the extensive studies already conducted on RCrA.
