Lowest accreting protoplanetary discs consistent with X-ray photoevaporation driving their final dispersal

Published in Monthly Notices of the Royal Astronomical Society, 2023

Recommended citation: Ercolano, Picogna & Monsch (2023). "Lowest accreting protoplanetary discs consistent with X-ray photoevaporation driving their final dispersal." Monthly Notices of the Royal Astronomical Society. 526, 1. https://academic.oup.com/mnrasl/article-abstract/526/1/L105/7260862

GitHub repository

Download paper

Abstract


Photoevaporation from high-energy stellar radiation has been thought to drive the dispersal of protoplanetary discs. Different theoretical models have been proposed, but their predictions diverge in terms of the rate and modality at which discs lose their mass, with significant implications for the formation and evolution of planets. In this paper, we use disc population synthesis models to interpret recent observations of the lowest accreting protoplanetary discs, comparing predictions from EUV-driven, FUV-driven, and X-ray-driven photoevaporation models. We show that the recent observational data of stars with low accretion rates (low accretors) point to X-ray photoevaporation as the preferred mechanism driving the final stages of protoplanetary disc dispersal. We also show that the distribution of accretion rates predicted by the X-ray photoevaporation model is consistent with observations, while other dispersal models tested here are clearly ruled out.

accretion rate density distributions
Histogram of the accretion rate density distribution in the EUV (blue), X-ray (orange), and FUV (green) population synthesis. The KDE is overplotted with a solid line for each distribution, and the median values are plotted with dot–dashed lines. For direct comparison, the median accretion rate of the low-accretor population is plotted with a black dot–dashed line. The distribution of accretion rates from the sample of Manara et al. (2023) is added with a black histogram in the full sample for comparison.