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Antilen, J., Casassus, S., Cieza, L. A., & Gonzalez-Ruilova, C. (2023). Gas distribution in ODISEA sources from ALMA long-baseline observations in (CO)-C-12(2-1). Mon. Not. Roy. Astron. Soc., 522(2), 2611–2627.
Abstract: The (CO)-C-12 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 (CO)-C-12(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 similar to 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 (CO)-C-12(2-1), except for the compact signal located inside its dust cavity. Our observations also point out a possible outflow in WLY 2-63.
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Ruiz-Rodriguez, D. A., Cieza, L. A., Casassus, S., Almendros-Abad, V., Jofre, P., Muzic, K., et al. (2022). Discovery of a Brown Dwarf with Quasi-spherical Mass Loss. Astrophys. J., 938(1), 54.
Abstract: We report the serendipitous discovery of an elliptical shell of CO associated with the faint stellar object SSTc2d J163134.1-240060 as part of the “Ophiuchus Disk Survey Employing ALMA” (ODISEA), a project aiming to study the entire population of protoplanetary disks in the Ophiuchus Molecular Cloud from 230 GHz continuum emission and (CO)-C-12 (J = 2-1), (CO)-C-13 (J = 2-1) and (CCO)-C-18 (J = 2-1) lines readable in Band 6. Remarkably, we detect a bright (CO)-C-12 elliptical shape emission of similar to 3 '' x 4 '' toward SSTc2d J163134.1-240060 without a 230 GHz continuum detection. Based on the observed near-IR spectrum taken with the Very Large Telescope (KMOS), the brightness of the source, its three-dimensional motion, and Galactic dynamic arguments, we conclude that the source is not a giant star in the distant background (>5-10 kpc) and is most likely to be a young brown dwarf in the Ophiuchus cloud, at a distance of just similar to 139 pc. This is the first report of quasi-spherical mass loss in a young brown dwarf. We suggest that the observed shell could be associated with a thermal pulse produced by the fusion of deuterium, which is not yet well understood, but for a substellar object is expected to occur during a short period of time at an age of a few Myr, in agreement with the ages of the objects in the region. Other more exotic scenarios, such as a merger with planetary companions, cannot be ruled out from the current observations.
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