Theoretical Models

There are several types of models involved in the AGE-PRO collaboration in order to compare disk evolution simulations with the AGE-PRO data. This includes: thermochemical models, disk population models, dust evolution and radiative transfer simulations.

✩ Trapman et al. (AGE-PRO V) constrain gas disk masses by comparing observed line fluxes of CO isotopologues and N₂H⁺, CO gas disk sizes, and 1.3 mm continuum fluxes with a large grid of models computed using the thermochemical code DALI (Bruderer et al. 2012). DALI iteratively solves the radiative transfer, time-dependent chemistry, and thermal balance to compute the chemical and thermal structure of the disk. It determines the dust and gas temperatures, as well as molecular level populations and line emission. For the AGE-PRO analysis, the models incorporate CO isotope-selective chemistry and photodissociation to improve accuracy in interpreting CO isotopologue emission. The predicted line fluxes from the model grid, along with the MCMC fitting routine used to compare the models with observations, are available in zenodo.

Figure from Trapman et al. (AGE-PRO V). Comparison between the line luminosities for the AGE-PRO sources in Lupus and Upper Sco and the results from the thermochemical disk models.

✩ Kurtovic et al. (AGE-PRO VI) and Anania et al. (AGE-PRO VIII) use Dustpy, which is a gas and dust evolution code introduced in Stammler & Birnstiel (2022), which includes the dynamics and growth of dust particles simultaneously in protoplanetary disks based on the work of Birnstiel et al. (2010). Dustpy is publicly available at https://stammler.github.io/dustpy/.

In Kurtovic et al. (AGE-PRO VI), both the gas and dust evolution are calculated. For gas evolution, it is assumed viscous evolution, while for the dust evolution different models with dust traps were assumed. In Kurtovic et al. (AGE-PRO VI), radiative transfer models were performed using the publicly available code RADMC-3D, published in Dullemond et al. (2012). For the calculation of the dust opacities, we use optool, published in Dominik et al. (2021). To access the scripts used to run the Dustpy, RADMC-3D, or optool calculations used in the AGE-PRO collaboration, please contact Dr. Nicolas Kurtovic.

Figure from Kurtovic et al. (AGE-PRO VI), showing an example of the radial (left panel) and vertical (middle and right panels) dust density distribution assuming three dust traps in the disk.

In Anania et al. (AGE-PRO VIII) both gas and dust evolution models of smooth discs were performed using the grid-based code DustPy presented in Stammler & Birnstiel (2022). For these models, external photoevaporation is included based on the work by Garate et al. (2024)and Sellek et al. (2020), using the FRIED grid developed by Tom Haworth, recently updated and published in Haworth et al. (2023). A repository with the latest implementation of external photoevaporation in Dustpy is available here.

Figure from Anania et al.(AGE-PRO VIII) showing an example of the gas density evolution when external photoevaporation is included (G₀=10) in the models (color lines) in comparison with only viscous evolution models (grey lines).

✩ In Tabone et al. (AGE-PRO VII) the gas evolution of protoplanetary disks is modelled either using viscous evolution or MHD wind-driven evolution as analytically implemented in in Tabone et al. (2022). The viscous evolution models include photoevaporation from X-ray irradiation from the central star, as explained in Picogna et al. (2021). For the population synthesis models, we use the Diskpop python package developed by Somigliana et al. (2024). To request access to the scripts use in Tabone et al. (AGE-PRO VII), please contact Dr. Benoî Tabone.

Figures from Tabone et al. (AGE-PRO VII) comparing different disk observables to population synthesis MWD wind models (left) to viscous plus internal photoevaporation models (right).