Towards a population synthesis of discs and planets. II. Confronting disc models and observations at the population level

Abstract

Aims. We want to find the distribution of initial conditions that best reproduces disc observations at the population level. Methods. We first ran a parameter study using a 1D model that includes the viscous evolution of a gas disc, dust, and pebbles, coupled with an emission model to compute the millimetre flux observable with ALMA. This was used to train a machine learning surrogate model that can compute the relevant quantity for comparison with observations in seconds. This surrogate model was used to perform parameter studies and synthetic disc populations.Results. Performing a parameter study, we find that internal photoevaporation leads to a lower dependency of disc lifetime on stellar mass than external photoevaporation. This dependence should be investigated in the future. Performing population synthesis, we find that under the combined losses of internal and external photoevaporation, discs are too short lived. Conclusions. To match observational constraints, future models of disc evolution need to include one or a combination of the following processes: infall of material to replenish the discs, shielding of the disc from internal photoevaporation due to magnetically driven disc winds, and extinction of external high-energy radiation. Nevertheless, disc properties in low-external-photoevaporation regions can be reproduced by having more massive and compact discs. Here, the optimum values of the α viscosity parameter lie between 3 × 10 −4 and 10 −3 and with internal photoevaporation being the main mode of disc dispersal.

Survey of Orion Disks with ALMA (SODA)

“…The median star in the galaxy is formed in a region with a higher surface density of young stars, and -as a result of the stellar mass distribution -will be within a few pc of an O-or B-type young star at some point in its early life (Winter & Haworth 2022). These young, massive stars affect the survival of disks in nearby stars through photo-evaporation, as shown by the presence of proplyds (O'Dell et al 1993) and by theoretical work (e.g., Scally & Clarke 2001;Haworth et al 2018;Concha-Ramírez et al 2019;Emsenhuber et al 2023). In the immediate proximity of O-type stars, EUV photons drive mass loss (for instance, within 0.3 pc of θ 1 Ori C (O6; Störzer & Hollenbach 1999).…”