Testing the formation mechanism of sub-stellar objects in Lupus (a SOLA team study) Brown dwarfs (BDs) are substellar objects with masses too low (M≤0.08MSUN) to burn hydrogen in their cores, some of them comparable with the mass of giant planets (M<0.013MSUN). Over the past two decades, a large number of brown dwarfs have been identified in star forming regions, open clusters, and in the field. However, it is still unclear how these objects form. The most widely discussed scenarios for the formation of BDs include turbulent fragmentation (Padoan & Nordlund 2004), disk fragmentation and subsequent ejection (Stamatellos & Whitworth 2009), photo-evaporation of massive pre-stellar cores (Whitworth & Zinnecker 2004), and ejection from multiple protostellar systems (Bate et al. 2002). Since stars and brown dwarfs evolve very rapidly during the first million years, the answer to the formation mechanism (or mechanisms) must be in the study of their properties when they are deeply embedded in the natal cloud, what we call the pre- and proto-BD stage. I. de Gregorio-Monsalvo1,2, C. López1,3; S. Takahashi1,4; A. Santamaría-Miranda2, 10, P. Cortés,1,3; F. Comerón2; A. Hales1,3; L. Knee5; D. Mardones6; K. Muzic7; A. Plunkett2; M. Saito4; K. Tachihara8; T. van Kempen9 , and the rest of the SOLA* collaboration. (1) Joint ALMA Observatory (Chile), (2) ESO (Chile), (3) NRAO (USA), (4) NAOJ (Japan), (5) CNRS (Canada), (6) U. Chile (Chile) , (7) CENTRA, U. of Lisbon (Portugal), (8) Nagoya U. (Japan), (9) SRON Netherlands Institute for Space Research, (10) U. Valparaíso (Chile), (*) Soul of Lupus with ALMA collaboration Submillimeter emission of substellar objects in Lupus I and III Lupus I and III southern molecular clouds are excellent laboratories to study the formation processes of sub-stellar objects. Our group (SOLA team) has identified a set of pre- and proto-stellar candidates of substellar nature using the literature as well as 1.1mm ASTE/AzTEC maps and analyzing its SED using our optical to submillimeter database. We performed ALMA continuum observations at 1.3mm and CO(2-1) using 0.8" spatial resolution towards the most promising pre- and proto-brown dwarfs candidates found in Lupus I and III molecular complexes. Our sample comprises 33 pre-stellar objects, 7 Class 0 and I objects, and 22 Class II objects. Lupus I Lupus III A B C D E F G H A B C D E F a b a b Fig 1 and 2: Central big maps represents Herschel SPIRE emission at 250 microns of Lupus I (left) and Lupus III (right). Smaller maps surrounding SPIRE maps are new ALMA continuum detections (> 6 sigma) at 1.3 mm. I Preliminary Results • Preliminary analysis of our data reveals ALMA continuum emission at 1.3mm in 17 source (see small panels in Figures 1 and 2), with object Lupus I-D being a submillimeter galaxy gravitationally lensed (Tamura et al. 2015) . Assuming the rest of the sources are associated to Lupus, we obtained a detection rate of ~30%. • Assuming emission at 1.3 mm is coming from dust, and adopting a Tdust = 10-15 K, a distance to Lupus d = 150-200 pc, a κν = 0.009 cm2 g-1 , and a gas to dust ratio of 100, we infer a Mass <0.013 Msun for all objects except for Lupus III-G (a known young stellar object surrounded by a protoplanetary disk), which falls into the range of planetary masses. • Using our multiwavelength SOLA catalog we checked for counterparts at other wavelengths and we analyzed the SEDs. LupusI- B, C, Ab, Fa, Fb, and E, and Lupus III – A, B, E, and F are deeply embedded protostars or starless pre-BD candidates, with no known counterpart at shorter wavelengths. Most of them are not resolved spatially and they would need to have a radius between 3 to 42 AU to be gravitationally unstable. Their real nature need to be further investigated. No extragalactic counterparts are found in the NED catalogue at the position of these objects. Lupus I – Aa is a sub-luminous (Lbol = 0.0026 Lsun) Class 0-I source, and Lupus III-C is a sub-luminous (Lbo l= 0.023 Lsun ) C