The ALMA Survey of Gas Evolution of PROtoplanetary Disks (AGE-PRO). II. Dust and Gas Disk Properties in the Ophiuchus Star-forming Region

Abstract The ALMA survey of Gas Evolution in PROtoplanetary disks (AGE-PRO) Large Program aims to trace the evolution of gas disk mass and size throughout the lifetime of protoplanetary disks by using the Atacama Large Millimeter/submillimeter Array (ALMA). This paper presents Band-6 ALMA observations of 10 embedded (Class I and Flat Spectrum) sources in the Ophiuchus molecular cloud, with spectral types ranging from M3 to K6 stars, which serve as the evolutionary starting point in the AGE-PRO sample. While we find four nearly edge-on disks (≥70°), and three highly inclined disks (≥60 ° ) in our sample, we show that, as a population, embedded disks in Ophiuchus are not significantly contaminated by more-evolved, but highly inclined sources. We derived dust disk masses from the Band-6 continuum and estimated gas disk masses from the C 18 O J = 2−1 and C 17 O J = 2−1 lines. The mass estimates from the C 17 O line are slightly higher, suggesting C 18 O emission might be partially optically thick. While the 12 CO and 13 CO lines are severely contaminated by extended emission and self-absorption, the C 18 O and C 17 O lines are allowed to trace the radial extent of the gaseous disks. From these measurements, we found that the C 18 O J = 2−1 and C 17 O J = 2−1 fluxes correlate well with each other and with the continuum fluxes. Furthermore, the C 18 O and C 17 O lines present a larger radial extension than disk dust sizes by factors ranging from ∼1.5 to ∼2.5, as is found for Class II disks using the radial extension of the 12 CO. In addition, we have detected outflows in three disks from 12 CO observations.