  Asymmetry in the spatially integrated, 1D HI global profiles of galaxies can
inform us on both internal (e.g. outflows) and external (e.g. mergers, tidal
interactions, ram pressure stripping) processes that shape galaxy evolution.
Understanding which of these primarily drive HI profile asymmetry is of
particular interest. In the lead-up to SKA pathfinder and SKA HI emission
surveys, hydrodynamical simulations have proved to be a useful resource for
such studies. Here we present the methodology behind, as well as first results,
of ASymba: Asymmetries in HI of Simba galaxies, the first time this simulation
suite has been used for this type of study. We generate mock observations of
the HI content of these galaxies and calculate the profile asymmetries using
three different methods. We find that $M_{\rm HI}$ has the strongest
correlation with all asymmetry measures, with weaker correlations also found
with the number of mergers a galaxy has undergone, and gas and galaxy rotation.
We also find good agreement with the xGASS sample, in that galaxies with highly
asymmetric profiles tend to have lower HI gas fractions than galaxies with
symmetric profiles, and additionally find the same holds in sSFR parameter
space. For low HI mass galaxies, it is difficult to distinguish between
asymmetric and symmetric galaxies, but this becomes achievable in the high HI
mass population. These results showcase the potential of ASymba and provide the
groundwork for further studies, including comparison to upcoming large HI
emission surveys.
