Stokes IQUV magnetic Doppler imaging of Ap stars- III. Next generation chemical abundance mapping of α2 CVn?

In a previous paper we presented an updated magnetic field map for the chemically pe-culiar star α2 CVn using ESPaDOnS and Narval time-resolved high-resolution Stokes IQUV spectra. In this paper we focus on mapping various chemical element distribu-tions on the surface of α2 CVn. With the new magnetic field map and new chemical abundance distributions we can investigate the interplay between the chemical abun-dance structures and the magnetic field topology on the surface of α2 CVn. Previous attempts at chemical abundance mapping of α2 CVn relied on lower resolution data. With our high resolution (R=65,000) dataset we present nine chemical abundance maps for the elements O, Si, Cl, Ti, Cr, Fe, Pr, Nd and Eu. We also derive an updated magnetic field map from Fe and Cr lines in Stokes IQUV and O and Cl in Stokes IV. These new maps are inferred from line profiles in Stokes IV using the magnetic Doppler imaging code invers10. We examine these new chemical maps and investigate correlations with the magnetic topology of α2 CVn. We show that chemical abundance distributions vary between elements, with two distinct groups of elements