Confirmation of the proto-brown dwarf SSTB213-J041757B and discovery of a nearby new candidate with ALMA and CARMA

Abstract

How Brown Dwarfs (BDs) form is still an unresolved question. In order to shed light into the different possible mechanisms for BD formation, it is essential to identify bona-fide BDs in their earliest evolutionary stages, the so-called proto-BDs, equivalent to objects in the Class 0 and Class I stages of young stellar objects. We conducted CARMA observations at 3 and 1 mm and several transitions, along with ALMA observations at 1 mm and CO(2-1) towards a debated proto-BD candidate in the Taurus molecular cloud. Both ALMA and CARMA observations reveal signs of outflow emission driven by the proto-BD candidate. In addition, CARMA allowed to discover a new proto-BD candidate about 50 arcsec to the northeast, that also seems to drive a molecular outflow. A comparison of the outflow momentum rate of these two proto-BD candidates with those of well-known young stellar objects indicates that this parameter falls at the expected relation according to their lower luminosity. Overall, these observations allow to add two proto-BDs in the short list of proto-BDs known to date, and suggest that BDs seem to form as a scaled-down version of low-mass stars. Funded by the UNAM-PAPIIT IN111421 grant.