The Progenitors of Local Ultra-Massive Galaxies Across Cosmic Time: From Dusty Star-Bursting to Quiescent Stellar Populations

Abstract

Using the UltraVISTA catalogs, we investigate the evolution in the 11.4 Gyr since z = 3 of the progenitors of local ultra-massive galaxies (log (M star /M ⊙ ) ≈ 11.8; UMGs), providing a complete and consistent picture of how the most massive galaxies at z = 0 have assembled. By selecting the progenitors with a semi-empirical approach using abundance matching, we infer a growth in stellar mass of 0.56 +0.35 −0.25 dex, 0.45 +0.16 −0.20 dex, and 0.27 +0.08 −0.12 dex from z = 3, z = 2, and z = 1, respectively, to z = 0. At z < 1, the progenitors of UMGs constitute a homogeneous population of only quiescent galaxies with old stellar populations. At z > 1, the contribution from star-forming galaxies progressively increases, with the progenitors at 2 < z < 3 being dominated by massive (M star ≈ 2 × 10 11 M ⊙ ), dusty (A V ∼1-2.2 mag), star-forming (SFR∼100-400 M ⊙ yr −1 ) galaxies with a large range in stellar ages. At z = 2.75, ∼15% of the progenitors are quiescent, with properties typical of post-starburst galaxies with little dust extinction and strong Balmer break, and showing a large scatter in color. Our findings indicate that at least half of the stellar content of local UMGs was assembled at z > 1, whereas the remaining was assembled via merging from z ∼ 1 to the present. Most of the quenching of the star-forming progenitors happened between z = 2.75 and z = 1.25, in good agreement with the typical formation redshift and scatter in age of z = 0 UMGs as derived from their fossil records. The progenitors of local UMGs, including the star-forming ones, never lived on the blue cloud since z = 3. We propose an alternative path for the formation of local UMGs that refines previously proposed pictures and that is fully consistent with our findings.

CONFIRMING THE EXISTENCE OF A QUIESCENT GALAXY POPULATION OUT TO z = 3: A STACKING ANALYSIS OF MID-, FAR-INFRARED, AND RADIO DATA

“…A redshift-dependent 24 μm flux density (S 24 ) cut-off 17 is then applied to separate the IR-bright QG candidates with SFR M 100 24   yr −1 , where SFR 24 is the SFR inferred from their 24 μm flux density (S 24 ; see Section 4.4 for derivation). The fraction of QG candidates with SFR M 100 24   yr −1 ( f QG,24 ) increases with z and peaks at 15% for the most massive ones at z  2 (see Table 1), qualitatively similar to the trend found in Marchesini et al (2014). This suggests a higher fraction of misclassified QG candidates at z  2, which results from a higher fraction of dusty galaxies at higher z (e.g., Greve et al 2010), and more uncertain rest-frame colors (Williams et al 2009).…”

The massive end of the luminosity and stellar mass functions and clustering from CMASS to SDSS: evidence for and against passive evolution

“…There also exists a large body of work which suggests -primarily on the basis of number counts alone -that there must have been of order 0.1 to 0.2 dex mass growth via mergers over the redshifts and masses of interest here (see e.g. Marchesini et al 2014;Ownsworth et al 2014 and references therein). Although we outlined a simple toy model for how abundance and clustering measurements constrain merger models (Appendix B), the exquisitely passive nature of φ(M * ) which we have found is a puzzle which we hope will spur further work.…”

The Next Generation Virgo Cluster Survey (NGVS). XXIV. The Red Sequence to ∼106 L⊙ and Comparisons with Galaxy Formation Models

“…10 M ] begin to appear as early as z = 4 (Fontana et al 2009;Muzzin et al 2013;Marchesini et al 2014) and finish assembling by z = 1-2 (Ilbert et al 2010;Brammer et al 2011). Growth in the stellar mass density of quiescent galaxies since z = 1, on the other hand, has occured at mass scales of M * and lower , consistent with downsizing.…”