The 12 CO gas structures of protoplanetary disks in the Upper Scorpius region
Year: 2025
Type: article
Abstract: We present measurements of key protoplanetary disk properties inferred from parametric models of ALMA 12 CO spectral line visibilities. We derived gas-disk radii, integrated fluxes, optically thick emission layers, and brightness temperature profiles for the disk population of the old (4–14 Myr) Upper Scorpius star-forming region. We measured CO emission sizes for 37 disks with bright CO J = 3–2 emission (S/N > 10 on the integrated flux; out of the 83 disks with CO detections), finding that the median radius containing 90% of the flux is ∼82 au, with radii spanning from 22 up to 247 au. We report a correlation between the 12 CO brightness temperatures and stellar luminosities, with a Pearson coefficient of 0.6, which we used to prove that the 12 CO optically thick emission layer primarily emanates from a region below the superheated dust, which is optically thin to the stellar irradiation. Moreover, we derive 33 CO emission-surface height profiles, finding a median aspect ratio of ⟨ z/r ⟩ ∼ 0.16 in a range from ∼0.01 up to ∼0.45 over the sample. Finally, we comment on the multiple systems in our sample, of which only some were already known. These results confirm that it is possible to derive bulk disk properties by modeling moderate-angular-resolution ALMA visibilities.
Source: Astronomy and Astrophysics
Institutions: European Southern Observatory, University of Milan, European Southern Observatory, Center for Astrophysics Harvard & Smithsonian, Atacama Large Millimeter Submillimeter Array, University College Dublin, Max Planck Society, Max Planck Institute for Extraterrestrial Physics, Max Planck Institute for Astronomy, University of Virginia, University of Cambridge, University of Michigan, Massachusetts Institute of Technology, Centre National de la Recherche Scientifique, Institut de Planétologie et d'Astrophysique de Grenoble, Université Grenoble Alpes, Institute of Astronomy and Astrophysics, Academia Sinica, Academia Sinica
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,865
OpenAlex ID: W4417417059