Carnall, A. C.A. C.CarnallMcLure, R. J.R. J.McLureDunlop, J. S.J. S.DunlopCullen, F.F.CullenMcLeod, D. J.D. J.McLeodWild, V.V.WildJohnson, B. D.B. D.JohnsonAppleby, S.S.ApplebyDavé, R.R.DavéAmorin, R.R.AmorinBOLZONELLA, MICOLMICOLBOLZONELLACASTELLANO, MARCOMARCOCASTELLANOCimatti, A.A.CimattiCUCCIATI, OlgaOlgaCUCCIATIGARGIULO, ADRIANAADRIANAGARGIULOGARILLI, BIANCA MARIA ROSABIANCA MARIA ROSAGARILLIMARCHI, FRANCESCAFRANCESCAMARCHIPENTERICCI, LauraLauraPENTERICCIPOZZETTI, LuciaLuciaPOZZETTISchreiber, C.C.SchreiberTalia, M.M.TaliaZamorani, G.G.Zamorani2021-01-212021-01-2120190035-8711http://hdl.handle.net/20.500.12386/29904We present a Bayesian full-spectral-fitting analysis of 75 massive (M_* > 10^{10.3} M_☉ ) UVJ-selected galaxies at redshifts of 1.0 < z < 1.3, combining extremely deep rest-frame ultraviolet spectroscopy from VANDELS with multiwavelength photometry. By the use of a sophisticated physical plus systematic uncertainties model, constructed within the BAGPIPES code, we place strong constraints on the star-formation histories (SFHs) of individual objects. We first constrain the stellar mass versus stellar age relationship, finding a steep trend towards earlier average formation time with increasing stellar mass (downsizing) of 1.48^{+0.34}_{-0.39} Gyr per decade in mass, although this shows signs of flattening at M_* > 10^{11} M_☉ . We show that this is consistent with other spectroscopic studies from 0 < z < 2. This relationship places strong constraints on the AGN-feedback models used in cosmological simulations. We demonstrate that, although the relationships predicted by SIMBA and ILLUSTRISTNG agree well with observations at z = 0.1, they are too shallow at z = 1, predicting an evolution of ≲0.5 Gyr per decade in mass. Secondly, we consider the connections between green-valley, post-starburst, and quiescent galaxies, using our inferred SFH shapes and the distributions of galaxy physical properties on the UVJ diagram. The majority of our lowest-mass galaxies (M_* ∼ 10^{10.5} M_☉ ) are consistent with formation in recent (z < 2), intense starburst events, with time-scales of ≲500 Myr. A second class of objects experience extended star-formation epochs before rapidly quenching, passing through both green-valley and post-starburst phases. The most massive galaxies in our sample are extreme systems: already old by z = 1, they formed at z ∼ 5 and quenched by z = 3. However, we find evidence for their continued evolution through both AGN and rejuvenated star-formation activity.STAMPAenArticle10.1093/mnras/stz25442-s2.0-85075242938000496922300032https://academic.oup.com/mnras/article/490/1/417/5568380https://arxiv.org/abs/1903.110822019MNRAS.490..417CFIS/05 - ASTRONOMIA E ASTROFISICAERC sectors::Physical Sciences and Engineering::PE9 Universe sciences: astro-physics/chemistry/biology; solar systems; stellar, galactic and extragalactic astronomy, planetary systems, cosmology, space science, instrumentation::PE9_6 Stars and stellar systems