Mówca
Opis
The 6.7 GHz methanol maser transition is one of the most powerful tracers of high-mass star-forming regions. We present results from an unique, long-term monitoring program carried out with the Toruń 32-m radio telescope, covering a sample of over 250 methanol sources across the Galactic plane. The monitoring campaign has revealed a rich diversity of variability behaviours, including the discovery of a new class of periodic and alternating flares — most notably the simultaneous, anti-correlated variability of methanol and water masers in a single young stellar object, representing a phenomenon with no prior observational counterpart. To investigate the spatial structure and kinematics of selected sources, high-resolution imaging was performed using the European VLBI Network (EVN) at milliarcsecond angular resolution, resolving the maser emission into compact clusters tracing accretion discs and/or outflows. Recent simultaneous observations of 6.035 GHz OH and 6.7 GHz methanol masers using eMERLIN allowed to constrain physical condition in the close environments of forming high-mass stars.