How does the host galaxy morphology influence a central quasar or vice versa? We address this question by measuring the asymmetries of 2424 SDSS quasar hosts at 0.2 < z 45). This then manifests itself into quasar hosts being more asymmetric, on average, when they harbour a more massive and highly accreting black hole. The merger fraction also positively correlates with Lbol and reaches up to 35 per cent for the most luminous. Compared to control galaxies, quasar hosts are marginally more asymmetric (excess of 0.017 in median at 9.4{sigma} level) and the merger fractions are similar (~16.5 per cent). We quantify the dependence of asymmetry on optical band that demonstrates that mergers are more likely to be identified with the bluer bands and the correlation between Lbol and asymmetry is also stronger in such bands. We stress that the band dependence, indicative of a changing stellar population, is an important factor in considering the influence of mergers on AGN activity.

Cone search capability for table J/MNRAS/521/5272/table2 (*Astrometry, photometry, physical properties and asymmetry measurements for quasar hosts)

Cone search capability for table J/MNRAS/521/5272/table3 (*Astrometry, photometry, physical properties and asymmetry measurements for control galaxies)