Preparing for low surface brightness science with the Vera C. Rubin
  Observatory: characterisation of tidal features from mock images
  Tidal features in the outskirts of galaxies yield unique information about
their past interactions and are a key prediction of the hierarchical structure
formation paradigm. The Vera C. Rubin Observatory is poised to deliver deep
observations for potentially of millions of objects with visible tidal
features, but the inference of galaxy interaction histories from such features
is not straightforward. Utilising automated techniques and human visual
classification in conjunction with realistic mock images produced using the
NEWHORIZON cosmological simulation, we investigate the nature, frequency and
visibility of tidal features and debris across a range of environments and
stellar masses. In our simulated sample, around 80 per cent of the flux in the
tidal features around Milky Way or greater mass galaxies is detected at the
10-year depth of the Legacy Survey of Space and Time (30-31 mag / sq. arcsec),
falling to 60 per cent assuming a shallower final depth of 29.5 mag / sq.
arcsec. The fraction of total flux found in tidal features increases towards
higher masses, rising to 10 per cent for the most massive objects in our sample
(M*~10^{11.5} Msun). When observed at sufficient depth, such objects frequently
exhibit many distinct tidal features with complex shapes. The interpretation
and characterisation of such features varies significantly with image depth and
object orientation, introducing significant biases in their classification.
Assuming the data reduction pipeline is properly optimised, we expect the Rubin
Observatory to be capable of recovering much of the flux found in the outskirts
of Milky Way mass galaxies, even at intermediate redshifts (z<0.2).
