H2O maser flares in the source W75 N

We present the results of our study of the H2O maser emission in the intricate complex of active star formationW75 N.Our observations have been carried out at the 22-m radio telescope of the Pushchino Radio AstronomyObservatory. A possible identification of its flares with the sources VLA 1 and VLA 2 has been made. Two cycles of maser activity have been detected: 2006–2012 and 2012–2015. The main H2O maser flares occurred in VLA 1. Analysis of the evolution of the flares has shown that the flare emission is associated with a cluster of maser condensations with close radial velocities up to ~2 AU in extent. The medium in which the maser emission is generated is turbulent with various turbulence scales. Our investigation of the line shape at the epochs of flare maxima has also shown the absence of structures of the simplest form, homogeneous maser condensations. The emission in the velocity range from −10.5 to −12 km s−1 has been identified with a structure like an elongated filament with an extent of ~4 AU.