2017/01/28 by Ruobing Dong, Nienke van der Marel, Jun Hashimoto +24 · 1 citation
Chemistry · Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Drop (telecommunication) #Isotopologue #Millimeter #Molecular Spectroscopy and Structure #Physics #RADIUS #Spectral line #Stellar, planetary, and galactic studies #astro-ph.EP #astro-ph.GA #astro-ph.SR
paper · pdf · doi:10.3847/1538-4357/aa5abf
34 pages (single column), 13 figures, ApJ in press
arxiv created 2017/01/28 · openalex publication_date 2017/02/20 · arxiv updated 2017/03/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Abstract We report ALMA Cycle 2 observations of 230 GHz (1.3 mm) dust continuum emission, and 12 CO, 13 CO, and C 18 O J = 2–1 line emission, from the Upper Scorpius transitional disk [PZ99] J160421.7-213028, with an angular resolution of ∼ (35 au). Armed with these data and existing H-band scattered light observations, we measure the size and depth of the disk’s central cavity, and the sharpness of its outer edge, in three components: sub -μ m-sized “small” dust traced by scattered light, millimeter-sized “big” dust traced by the millimeter continuum, and gas traced by line emission. Both dust populations feature a cavity of radius ∼70 au that is depleted by factors of at least 1000 relative to the dust density just outside. The millimeter continuum data are well explained by a cavity with a sharp edge. Scattered light observations can be fitted with a cavity in small dust that has either a sharp edge at 60 au, or an edge that transitions smoothly over an annular width of 10 au near 60 au. In gas, the data are consistent with a cavity that is smaller, about 15 au in radius, and whose surface density at 15 au is times smaller than the surface density at 70 au; the gas density grades smoothly between these two radii. The CO isotopologue observations rule out a sharp drop in gas surface density at 30 au or a double-drop model, as found by previous modeling. Future observations are needed to assess the nature of these gas and dust cavities (e.g., whether they are opened by multiple as-yet-unseen planets or photoevaporation).