Flybys in protoplanetary discs: II. Observational signatures
  Tidal encounters in star clusters perturb discs around young protostars. In
Cuello et al. (2019a, Paper I) we detailed the dynamical signatures of a
stellar flyby in both gas and dust. Flybys produce warped discs, spirals with
evolving pitch angles, increasing accretion rates, and disc truncation. Here we
present the corresponding observational signatures of these features in
optical/near-infrared scattered light and (sub-) millimeter continuum and CO
line emission. Using representative prograde and retrograde encounters for
direct comparison, we post-process hydrodynamical simulations with radiative
transfer methods to generate a catalogue of multi-wavelength observations. This
provides a reference to identify flybys in recent near-infrared and
sub-millimetre observations (e.g., RW Aur, AS 205, HV Tau & DO Tau, FU Ori,
V2775 Ori, and Z CMa).
