Multi-scale view of star formation in IRAS 21078+5211: from clump fragmentation to disk wind

In the massive star-forming region IRAS 21078+5211, a highly fragmented cluster (0.1~pc in size) of molecular cores is observed, located at density peak an elongated (1~pc cloud. A small (1~km/s per 0.1~pc) LSR velocity (Vlsr) gradient detected across axis Assuming we are observing mass flow from harboring cloud to cluster, derive infall rate about 10^{-4}~M_{sun}~yr^{-1}. The most (labeled 1, 2, and 3) found center these only ones that present signature protostellar activity terms emission high-excitation lines or outflow. We reveal extended (size 0.1~pc), bipolar collimated outflow emerging core 1. believe this powered by (previously discovered) compact <= 1000~au) radio jet, ejected YSO embedded 1 (named YSO-1), since jet almost parallel have comparable momentum rate. By means lines, find large (14~km/s over 500~au) Vlsr position YSO-1, oriented approximately perpendicular jet. edge-on, rotating disk fitting Keplerian rotation pattern, determine YSO-1 be 5.6+/-2.0~M_{sun}. water masers observed with VLBI) emerge within 100-300~au unique tracers kinematics. Their three-dimensional (3D) pattern reveals gas flows along, rotates about, axis. show 3D maser velocities fully consistent magneto-centrifugal disk-wind models predicting cylindrical Under hypothesis, radius 16~au corresponding launching terminal 2.2~au 200~km/s, respectively.