New Analytic Solutions for Galaxy Evolution: Gas, Stars, Metals, and Dust in Local ETGs and Their High-z Star-forming Progenitors

Abstract

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-...

Cosmology with the submillimetre galaxies magnification bias: Proof of concept

“…Since M are the satellite masses, they are a proxy of the minimum mass (galaxies with no satellites), but it has to be expressed in terms of halo mass in order to be considered a limit on M min . We translate these stellar masses in the corresponding mass of the halo using the recipe by Pantoni et al (2019) to switch from log M (h −1 M ) to log M h . Sifón et al (2015) gives values of log M (h −1 M ) between 9.5 and 11.5, which correspond to the range log M h = 11.6−13.6.…”

“…In particular, we focus on their Table 1; it gives values of log M (h −1 M ) between 10.36 and 10.81, the lowest possible value being in Bin 1 (taking into account the lower error) and the highest possible value in Bin 3 (taking into account the upper error). Such stellar masses translate (using Pantoni et al 2019) into log M h (M ) between 12.3 and 12.5. So, we choose a mean value of µ = 12.4 and a dispersion of σ = 0.1 for the Gaussian priors.…”

“…The results are listed in Table 5. The Gaussian priors are set to the µ and σ values presented by Viola et al (2015), Sifón et al (2015), and Pantoni et al (2019). The contours for these plots are set to 0.393 and 0.865 (see text for details).…”

In pursuit of giants

“…In addition to observational efforts over the last decade, a great deal of attention has been paid to theoretical studies of the formation of DSFGs and their dark matter (DM) halos via the application of different classes of cosmological simulations (Hayward 2013;Narayanan et al 2015;McKinnon et al 2017;Davé et al 2019;Aoyama et al 2019) or semi-analytic and analytic methods (Lacey et al 2016;Popping et al 2017;Imara et al 2018;Cousin et al 2019;Vijayan et al 2019;Lagos et al 2019;Pantoni et al 2019). To investigate the evolution of the dust content of high-z DSFGs, the models have made significant progress by replacing the simplified scaling relations with the physical recipes for self-consistent dust formation, growth, and destruction in evolving galaxies (e.g.…”

Growth of Supermassive Black Hole Seeds in ETG Star-forming Progenitors: Multiple Merging of Stellar Compact Remnants via Gaseous Dynamical Friction and Gravitational-wave Emission

“…However, two occurrences mitigate the effect. First, most of remnants relevant to the growth of the BH seed are formed and migrate to the center within a few 10 7 yr, when the average gas metallicity amounts to Z /10 (e.g., Pantoni et al 2019;Boco et al 2019); in these conditions, most of the remnants are formed by direct collapse without undergoing a SN explosions (e.g., Spera et al 2015;Spera & Mapelli 2017). Second, even if the SN explodes, it can efficiently sweep up material during the energy-conserving expansion phase, out to a radius R SN ∼ 5 t pc where E 51 ≡ E SN /10 51 erg is the energy of a SN explosion, n 2 ≡ n/10 2 cm −3 is the average gas density and t 4 ≡ t/10 4 yr the time since the explosion (e.g., Ostriker & McKee 1988;Mo et al 2010); however, once formed the remnant will move in the gaseous medium at a typical velocity of σ 200 ≡ σ/200 km s −1 and thus will travel a distance R rem ∼ 2 σ 200 t 4 pc, implying that most of the gas mass swept up by the remnant is replaced after 10 5 yr.…”