Demographics of young stars and their protoplanetary disks: lessons learned on disk evolution and its connection to planet formation

Abstract

Since Protostars and Planets VI (PPVI), our knowledge of the global properties of protoplanetary and debris disks, as well as of young stars, has dramatically improved. At the time of PPVI, mm-observations and optical to near-infrared spectroscopic surveys were largely limited to the Taurus star-forming region, especially of its most massive disk and stellar population. Now, near-complete surveys of multiple star-forming regions cover both spectroscopy of young stars and mm interferometry of their protoplanetary disks. This provides an unprecedented statistical sample of stellar masses and mass accretion rates, as well as disk masses and radii, for almost 1000 young stellar objects within 300 pc from us, while also sampling different evolutionary stages, ages, and environments. At the same time, surveys of debris disks are revealing the bulk properties of this class of more evolved objects. This chapter reviews the statistics of these measured global star and disk properties and discusses their constraints on theoretical models describing global disk evolution. Our comparisons of observations to theoretical model predictions extends beyond the traditional viscous evolution framework to include analytical descriptions of magnetic wind effects. Finally, we discuss how recent observational results can provide a framework for models of planet population synthesis and planet formation.

Penellope

“…Of particular relevance is how the material is transported through the disk and how it is accreted onto the central star (Hartmann et al 2016). Accretion regulates the final stellar mass, and it is commonly used in combination with the stellar and disk mass to constrain the models driving the global evolution of disks (Manara et al 2022).…”

Modelling the secular evolution of proto-planetary disc dust sizes -- A comparison between the viscous and magnetic wind case

“…To test the viscous and magnetic evolution model predictions, we compare our synthetic disc sizes with those observationally-inferred from Lupus (Ansdell et al 2016), Chamaeleon I (Pascucci et al 2016;Long et al 2018a) and Upper Sco (Barenfeld et al 2016) ALMA data in Band 7. We mainly refer to the work of Hendler et al (2020), who computed dust disc sizes homogeneously among these regions, and use the the PPVII Chapter table of Manara et al 2022, who adopted Gaia-EDR3 distances (Gaia Collaboration et al 2021. We choose these star-forming regions because they are among the best studied nearby ones, with high levels of completeness and disc detection fractions.…”

“…We compare dust disc sizes inferred from synthetic observations with those homogeneously computed by Hendler et al (2020) and Manara et al (2022). We restrict to the case of 𝛼 = 10 −3 and 10 −4 , because only in these cases purely magnetic wind models retain enough dust by 10 Myr.…”

“…Solid, dashed and dotted lines identify the evolutionary tracks with increasing values of 𝛼. Observations are shown as blue dots for Lupus and green dots for Upper Sco; downward-pointing triangles of the same colours are used for disc size upper limits. The data were taken from Hendler et al (2020) and Manara et al (2022). The observed correlations and their 1𝜎 scatter are displayed as grey dashed-dotted lines and shaded areas.…”

“…The data underlying this paper are available in the ALMA archive as explained in Hendler et al (2020) and Tazzari et al (2021a,b). The PPVII chapter summary table of Manara et al (2022)…”