On the connection between shape and stellar population in early-type galaxies

Authors :: D'Onofrio, M.
Valentinuzzi, T.
Fasano, G.
Moretti, A.
Bettoni, D.
Poggianti, B. M.
Vulcani, B.
Varela, J.
Fritz, J.
Cava, A.
Kjaergaard, P.
Moles, M.
Couch, W. J.
Dreller, A.
Publication Year :: 2010
Abstract: We report on the discovery of a relation between the stellar mass $M^*$ of early-type galaxies (hereafter ETGs), their shape, as parametrized by the Sersic index $n$, and their stellar mass-to-light ratio $M^*/L$. In a 3D log space defined by these variables the ETGs populate a plane surface with small scatter. This relation tells us that galaxy shape and stellar population are not independent physical variables, a result that must be accounted for by theories of galaxy formation and evolution.<br />Comment: 7 pages, 2 figures. Accepted on ApJL