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Dating the stellar population in massive early-type galaxies at $z\sim$1.5

M. Longhetti·P. Saracco·P. Severgnini·R. Della Ceca·V. Braito·F. Mannucci·R. Bender·N. Drory·G. Feulner·U. Hopp
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Abstract

We present the analysis of 10 massive early-type galaxies at $z\sim1.5$. They have been identified by means of a near-IR low resolution spectroscopic follow-up of a complete sample of 36 bright (K' $<$ 18.5) Extremely Red Objects (EROs, R-K'$>$ 5) selected from the Munich Near-IR ClusterSurvey (MUNICS; Drory et al. 2001). The low resolution near-IR spectra constrain their redshift at $1.2 2$ for all the galaxies and $z_{f} \geq 4$ for the oldest ones. The comparison of the 4000Åbreak and of the overall spectral shape of the average spectrum of the 10 galaxies at $z\sim1.5$ with those of their local counterpartsconfirms that field massive early-type galaxies formed the bulk of their stellar mass at $2<z<4$, most likely over a short ($<$ 1 Gyr) star formation time scale, consistently with the results derived from the analysis of their individual spectro-photometric properties.

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M. Longhetti, P. Saracco, P. Severgnini, R. Della Ceca, V. Braito, F. Mannucci, R. Bender, N. Drory, G. Feulner, U. Hopp. 2005-05-23. Dating the stellar population in massive early-type galaxies at $z\sim$1.5. https://doi.org/10.1111/j.1365-2966.2005.09215.x

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