The Luminosity-Size and Mass-Size Relations of Galaxies out to z~3

Trujillo, Ignacio; Rudnick, Gregory; Rix, Hans-Walter; Labbe, Ivo; Franx, Marijn; Daddi, Emanuele; Van Dokkum, Pieter G.; Schreiber, Natascha M. Forster; Kuijken, Konrad; Moorwood, Alan; Rottgering, Huub; Van De Wel, Arjen; Van Der Werf, Paul; Van Starkenburg, Lottie

The Luminosity-Size and Mass-Size Relations of Galaxies out to z~3

Authors

Van Dokkum, Pieter G.

Schreiber, Natascha M. Forster

Kuijken, Konrad

Moorwood, Alan

Description

The luminosity-size and stellar mass-size distributions of galaxies out to z~3 is presented. We use very deep near-infrared images of the Hubble Deep Field South in the J_s, H, and K_s bands, taken as part FIRES at the VLT, to follow the evolution of the optical rest-frame sizes of galaxies. For a total of 168 galaxies with K_{s,AB}<23.5, we find that the rest-frame V-band sizes r_{e,V} of luminous galaxies (<L_V>~2x10^{10}h^{-2}L_sun) at 2<z<3 are 3 times smaller than for equally luminous galaxies today. In contrast, the mass-size relation has evolved relatively little: the size at mass <M_*>~2x10^{10}h^{-2}M_sun, has changed by 20(+-20)% since z~2.5. Both results can be reconciled by the fact that the stellar M/L ratio is lower in the luminous high z galaxies than in nearby ones because they have young stellar populations. The lower incidence of large galaxies at z~3 seems to reflect the rarity of galaxies with high stellar mass.
39 pages, 14 figures, ApJ in press, new changes made to match the accepted version