We aim to provide a holistic view on the typical size and kinematic evolution of massive early-type galaxies (ETGs), that encompasses their high-z star-forming progenitors, their high-z quiescent counterparts, and their configurations in the local Universe. Our investigation covers the main processes playing a relevant role in the cosmic evolution of ETGs. Specifically, their early fast evolution comprises: biased collapse of the low angular momentum gaseous baryons located in the inner regions of the host dark matter halo; cooling, fragmentation, and infall of the gas down to the radius set by the centrifugal barrier; further rapid compaction via clump/gas migration toward the galaxy center, where strong heavily dust-enshrouded star-formation takes place and most of the stellar mass is accumulated; ejection of substantial gas amount from the inner regions by feedback processes, which causes a dramatic puffing up of the stellar component. In the late slow evolution, passive aging of stellar populations and mass additions by dry merger events occur. We describe these processes relying on prescriptions inspired by basic physical arguments and by numerical simulations, to derive new analytical estimates of the relevant sizes, timescales, and kinematic properties for individual galaxies along their evolution. Then we obtain quantitative results as a function of galaxy mass and redshift, and compare them to recent observational constraints on half-light size R e , on the ratio v/σ between rotation velocity and velocity dispersion (for gas and stars) and on the specific angular momentum j of the stellar component; we find good consistency with the available multi-band data in average values and dispersion, both for local ETGs and for their z ∼ 1 − 2 star-forming and quiescent progenitors. The outcomes of our analysis can provide hints to gauge sub-grid recipes implemented in simulations, to tune numerical experiments focused on specific processes, and to plan future multi-band, high-resolution observations on high-redshift star-forming and quiescent galaxies with next generation facilities.

We present a panchromatic study of 11 (sub-)millimetre selected DSFGs with spectroscopically confirmed redshift (1.5 < zspec < 3) in the GOODS-S field, with the aim of constraining their astrophysical properties (e.g. age, stellar mass, dust and gas content) and characterizing their role in the context of galaxy evolution. The multi-wavelength coverage of GOODS-S, from X-rays to radio band, allow us to model galaxy SED by using CIGALE with a novel approach, based on a physical motivated modelling of stellar light attenuation by dust. Median stellar mass (≃ 6.5 × 1010 M⊙) and SFR (≃ 241 M⊙ yr−1) are consistent with galaxy main-sequence at z ∼ 2. The galaxies are experiencing an intense and dusty burst of star formation (median LIR ≃ 2 × 1012 L⊙), with a median age of 750 Myr. The high median content of interstellar dust (Mdust ≃ 5 × 108 M⊙) suggests a rapid enrichment of the ISM (on timescales ∼108 yr). We derived galaxy total and molecular gas content from CO spectroscopy and/or Rayleigh-Jeans dust continuum (1010 ≲ Mgas/M⊙ ≲ 1011), depleted over a typical timescale τdepl ∼ 200 Myr. X-ray and radio luminosities (LX = 1042 − 1044 erg s−1, L1.5 GHz = 1030 − 1031 erg s−1, L6 GHz = 1029 − 1030 erg s−1) suggest that most of the galaxies hosts an accreting radio silent/quiet SMBH. This evidence, along with their compact multi-wavelength sizes (median rALMA ∼ rVLA = 1.8 kpc, rHST = 2.3 kpc) measured from high-resolution imaging (θres ≲ 1 arcsec), indicates these objects as the high-z star-forming counterparts of massive quiescent galaxies, as predicted e.g. by the in-situ scenario. Four objects show some signatures of a forthcoming/ongoing AGN feedback, that is thought to trigger the morphological transition from star-forming disks to ETGs.

We present a set of new analytic solutions aimed at self-consistently describing the spatially-averaged time evolution of the gas, stellar, metal, and dust content in an individual starforming galaxy hosted within a dark halo of given mass and formation redshift. Then, as an application, we show that our solutions, when coupled to specific prescriptions for parameter setting (inspired by in-situ galaxy-black hole coevolution scenarios) and merger rates (based on numerical simulations), can be exploited to reproduce the main statistical relationships followed by early-type galaxies and by their high-redshift starforming progenitors. Our analytic solutions allow to easily disentangle the diverse role of the main physical processes regulating galaxy formation, to quickly explore the related parameter space, and to make transparent predictions on spatially-averaged quantities. As such, our analytic solutions may provide a basis for improving the (subgrid) physical recipes presently implemented in theoretical approaches and numerical simulations, and can offer a benchmark for interpreting and forecasting current and future broadband observations of high-redshift starforming galaxies.2 PANTONI ET AL. evolution of the gas, stellar, metal, and dust content in an individual starforming galaxy hosted within a dark halo of given mass and formation redshift. Our basic framework pictures a galaxy as an open, one-zone system comprising three interlinked mass components: a reservoir of warm gas subject to cooling and condensation toward the central regions; cold gas fed by infall and depleted by star formation and stellar feedback (type-II supernovae [SNe] and stellar winds); stellar mass, partially restituted to the cold phase by stars during their evolution. Remarkably, the corresponding analytic solutions for the metal enrichment history of the cold gas and stellar mass are self-consistently derived using as input the solutions for the evolution of the mass components; the metal equations includes effects of feedback, astration, instantaneous production during star formation, and delayed production by type-Ia SNe, possibly following a specified delay time distribution. Finally, the dust mass evolution takes into account the formation of grain cores associated to star formation, and of the grain mantles due to accretion onto pre-existing cores; astration of dust by star formation and stellar feedback, and spallation by SN shockwaves are also included.We then apply our analytic solutions to describe the formation of spheroids/early-type galaxies (ETGs) and the evolution of their starforming progenitors. To this purpose, we couple our solutions to two additional ingredients: (i) specific prescriptions for parameter setting, inspired by in-situ galaxy-black hole coevolution scenarios of ETG formation; (ii) estimates of the halo and stellar mass growth by mergers, computed on the basis of the merger rates from state-of-the-art numerical simulations. We then derive and confront with available data a bunch of fundamental spatially-...