Galaxies bulge & disk data from SHARDS & HST

Using SHARDS and HST data, we modeled the surface brightness distribution of 91 massive galaxies at redshift 0.14<z<~1 in the wavelength range 0.5-1.6{mu}m, deriving the uncontaminated spectral energy distributions of their bulges and disks separately. This spectrophotometric decomposition allows us to compare the stellar population properties of each component in individual galaxies.

We find that the majority of massive galaxies (~85%) build inside-out, growing their extended stellar disk around the central spheroid. Some bulges and disks could start forming at similar epochs, but these bulges grow more rapidly than their disks, assembling 80% of their mass in ~0.7 and ~3.5Gyr, respectively. Moreover, we infer that both older bulges and older disks are more massive and compact than younger stellar structures.