Fernando Olguin (NTHU), Patricio Sanhueza (NAOJ), Vivien Chen (NTHU), Andres Guzman (NAOJ), Xing Lu (NAOJ)
Characterising the kinematics of massive cores is key to understand how high-mass stars in single or multiple systems form. These systems play an important role in galaxy evolution, but they can form by different mechanisms. Since high-resolution observations are needed to resolve individual cores, we are carrying a survey to look for binary/multiple systems in high-mass star forming regions with ALMA. One of the youngest and most massive star forming region in the Galaxy is located within the IRDC SDC335.579-0.272. Large scale infall motions have been observed in this region (Peretto et al. 2013), whilst ALMA and ATCA observations have started to resolve individual cores (Avison et al. 2015). In this presentation we will show the latest results from our analysis of 1.3 mm ALMA observations probing scales of 1000 au. These reveal a small clump of sources. We studied the kinematics of 2 sources which are likely forming high-mass stars: ALMA 1 and 3. The former is the most massive core in the region and its line emission shows rotation, infall and expanding motions in the circumstellar gas. The latter shows clear signs of rotation of an envelope and/or disc-like structure.