ALMA and VLA observations: evidence for ongoing low-mass star formation near Sgr A

Using the Very Large Array (VLA), we recently detected a large number of protoplanetary disc (proplyd) candidates lying within a couple of light years of the massive black hole Sgr A*. The bow-shock appearance of proplyd candidates points towards the young massive stars located near Sgr A*. Similar to Orion proplyds, the strong UV radiation from the cluster of massive stars at the Galactic centre is expected to photoevaporate and photoionize the circumstellar discs around young, low-mass stars, thus allowing detection of the ionized outflows from the photoionized layer surrounding cool and dense gaseous discs. To confirm this picture, ALMA observations detect millimeter emission at 226 GHz from five proplyd candidates that had been detected at 44 and 34 GHz with the VLA. We present the derived disc masses for four sources as a function of the assumed dust temperature. The mass of protoplanetary discs from cool dust emission ranges between 0.03 and 0.05 M-circle dot. These estimates are consistent with the disc masses found in star-forming sites in the Galaxy. These measurements show the presence of ongoing star formation with the implication that gas clouds can survive near Sgr A* and the relative importance of high-versus low-mass star formation in the strong tidal and radiation fields of the Galactic centre.