HI asymmetries with LVHIS, VIVA, and HALOGAS

With the aim of investigating the impact of the local environment density and stellar mass on the measured HI asymmetries in future large HI surveys, we provide recommendations for the most meaningful measures of asymmetry for use in future analysis.

After controlling for stellar mass, we find signs of statistically significant trends of increasing asymmetries with local density. The most significant trend we measure is for the normalized flipped spectrum residual (A_spec_), with mean LVHIS and VIVA values of 0.204+/-0.011 and 0.615+/-0.068 at average weighted 10th nearest-neighbour galaxy number densities of log({rho}_10_/Mpc^-3^) =-1.64 and 0.88, respectively. Looking ahead to the Widefield ASKAP L-band Legacy All-sky Blind survey on the Australian Square Kilometre Array Pathfinder, we estimate that the number of detections will be sufficient to provide coverage over 5 orders of magnitude in both local density and stellar mass increasing the dynamic range and accuracy with which we can probe the effect of these properties on the asymmetry in the distribution of atomic gas in galaxies.