Massive and evolved galaxies at z≳5

We search for massive and evolved galaxies at z >= 5 in the Great Observatories Origins Deep Survey (GOODS) southern field. Combining HST ACS, VLT ISAAC and Spitzer IRAC broad-band photometric data, we develop a color selection technique to identify candidates for being evolved galaxies at high redshifts. The color selection is primarily based on locating the Balmer-break using the K- and 3.6 mu m hands. Stellar population synthesis models are fitted to the SEDs of these galaxies to identify the final sample. We find 11 candidates with photometric redshifts in the range 4.9 < z < 5.6, dominated by an old stellar population, with ages 0.2-1.0 Gyr, and stellar masses in the range (0.7 - 5) X 10(11) M-circle dot. Most of the candidates have modest amounts of internal dust extinction. The majority of the stars in these galaxies were formed at z > 9 and the current star formation activity is a few percent of the inferred initial star formation rate.