Nauchni, Simferopol, Russian Federation
Results of systematic observations of a sample of bright H2O maser sources with fluxes, on average, exceeding 200 Jy in their main spectral feature during April- September 2017 (G25.65+1.05, G25.825-0.178, G27.184-0.082, G34.403+0.233, G35.20-0.74, G43.8-0.13, G107.30+5.64) are presented. These observations were carried out in preparation for Very Long Baseline Interferometry observations with an array including the Crimean Astrophysical Observatory 22-m radio telescope. All these sources display fairly strong variability during the time interval considered, encompassing fluxes from ∼40 to ∼2300 Jy. A flare reaching ∼17 000 Jy was detected at a velocity of 42.8 km/s in G25.65+1.05 on September 7, 2017, which subsequently grew to 60 000 Jy at the end of September 2017. This suggests the presence of compactmaser structures.
radio telescope, radio emission, flare, maser
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