Gas distribution in ODISEA sources from ALMA long-baseline observations in 12CO(2-1)

Abstract

ABSTRACT The 12CO rotational lines in protoplanetary discs are good tracers of the total spatial extension of the gas component, and potentially planet–disc interactions. We present ALMA long baseline observations of the 12CO(2-1) line of 10 protoplanetary discs from the Ophiuchus DIsc Survey Employing ALMA (ODISEA) project, aiming to set constraints on the gas distribution of these sources. The position angle of the gaseous disc can be inferred for five sources using high-velocity channels, which trace the gas in the inner part of the disc. We compare the high-velocity PAs to the orientations inferred from the continuum, representative of the orientation over ∼53 to 256 au in these resolved discs. We find a significant difference in orientation for DoAr 44, which is evidence of a tilted inner disc. Eight discs show evidence of gas inside inner dust cavities or gaps, and the disc of ISO-Oph 196 is not detected in 12CO(2-1), except for the compact signal located inside its dust cavity. Our observations also point out a possible outflow in WLY 2-63.