DEMOS. II. What the full Lupus demographics truly tell us about protoplanetary disc evolution
Abstract
Assessing whether disc evolution is driven by viscosity or MHD winds is crucial to determine the conditions in which planets form. The rich statistical information encoded in nearby star-forming regions provides an excellent opportunity to probe disc evolution. In this paper, we apply the Bayesian inference tool DEMOS, designed to exploit the statistical properties of disc populations and infer initial conditions and model parameters, to the Lupus disc population. We consider the observed distributions of stellar mass M⋆, disc mass M (from continuum flux), mass accretion rate Ṁ and CO disc size R90%, CO. We constrain all parameters for both the viscous model, with internal photoevaporation, and the MHD winds model, with unprecedented precision. The inferred initial conditions suggest that positive correlations between initial disc properties and M⋆ must be present. Both models yield a typical R0 of 3−5 au for a disc around a 0.3 M⊙ star, with positive stellar-mass dependence. We infer α (or αDW) of 3−4 × 10−4 for discs around 0.3 M⊙ stars, with an approximately quadratic dependence on M⋆. For the viscous-photoevaporative model, the typical wind mass-loss rate is Ṁw ∼ 10−9 M⊙ yr−1, scaling with M⋆ with an exponent of ∼ 2.5. The inferred mean age is 1.6 Myr for the MHD winds model and 0.9 Myr for the viscous-photoevaporative model. Despite a slight preference for the latter, Bayesian evidence shows that both models reproduce the data comparably well, and neither can be ruled out. However, their best-fit synthetic populations predict substantially different evolutionary pathways. Applying DEMOS to multiple populations, especially evolved ones like Upper Scorpius, will allow to place stronger constraints on disc evolution mechanisms.
Related
- DEMOS I. A Bayesian inference framework to constrain disc evolution from observed demographics
- Population demographics of post-interaction WDMS binaries: From common envelope evolution to stable mass transfer
- The ALMA Survey of Gas Evolution of PROtoplanetary disks (AGE-PRO): Evolution of dust properties from multi-wavelength observations
- The ALMA Survey of Gas Evolution of PROtoplanetary disks (AGE-PRO): Evolution of dust properties from multi-wavelength observations
- Testing Models of Disk Formation and Gravito-Viscous Evolution Against Observations of Young Protoplanetary Disks
BibTeX
@misc{malanga2026demos,
title = {{DEMOS. II. What the full Lupus demographics truly tell us about protoplanetary disc evolution}},
author = {Lorenzo A. Malanga and Giovanni P. Rosotti and Giuseppe Lodato and Alice Somigliana and Benoît Tabone and Rossella Anania and Carlo F. Manara and Leonardo Testi and Claudia Toci and Francesco Zagaria},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.17284},
eprint = {2610.17284},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.17284},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - DEMOS. II. What the full Lupus demographics truly tell us about protoplanetary disc evolution
AU - Lorenzo A. Malanga
AU - Giovanni P. Rosotti
AU - Giuseppe Lodato
AU - Alice Somigliana
AU - Benoît Tabone
AU - Rossella Anania
AU - Carlo F. Manara
AU - Leonardo Testi
AU - Claudia Toci
AU - Francesco Zagaria
PY - 2026
DA - 2026/10/12
PB - arXiv
DO - 10.48550/arxiv.2610.17284
UR - https://arxiv.org/abs/2610.17284
AB - Assessing whether disc evolution is driven by viscosity or MHD winds is crucial to determine the conditions in which planets form. The rich statistical information encoded in nearby star-forming regions provides an excellent opportunity to probe disc evolution. In this paper, we apply the Bayesian inference tool DEMOS, designed to exploit the statistical properties of disc populations and infer initial conditions and model parameters, to the Lupus disc population. We consider the observed distributions of stellar mass M_⋆, disc mass M (from continuum flux), mass accretion rate Ṁ and CO disc size R_90%, CO. We constrain all parameters for both the viscous model, with internal photoevaporation, and the MHD winds model, with unprecedented precision. The inferred initial conditions suggest that positive correlations between initial disc properties and M_⋆ must be present. Both models yield a typical R_0 of 3−5 au for a disc around a 0.3 M_⊙ star, with positive stellar-mass dependence. We infer α (or α_DW) of 3−4 × 10^−4 for discs around 0.3 M_⊙ stars, with an approximately quadratic dependence on M_⋆. For the viscous-photoevaporative model, the typical wind mass-loss rate is Ṁ_w ∼ 10^−9 M_⊙ yr^−1, scaling with M_⋆ with an exponent of ∼ 2.5. The inferred mean age is 1.6 Myr for the MHD winds model and 0.9 Myr for the viscous-photoevaporative model. Despite a slight preference for the latter, Bayesian evidence shows that both models reproduce the data comparably well, and neither can be ruled out. However, their best-fit synthetic populations predict substantially different evolutionary pathways. Applying DEMOS to multiple populations, especially evolved ones like Upper Scorpius, will allow to place stronger constraints on disc evolution mechanisms.
ER -