1. a Institute of Radio Astronomy, National Academy of Sciences of Ukraine, 4, Krasnoznamennaya St., Kharkiv 61002, Ukraine
2. b Institute of Radio Astronomy, National Academy of Sciences of Ukraine, 4, Krasnoznamennaya St., Kharkiv 61002, Ukraine; School of Radio Physics, Karazin Kharkiv National University, 4, Svobody Square, Kharkiv 61077, Ukraine
3. c Institute of Radio Astronomy, National Academy of Sciences of Ukraine, 4, Krasnoznamennaya St., Kharkiv 61002, Ukraine; School of Radio Physics, Karazin Kharkiv National University, 4, Svobody Square, Kharkiv 61077, Ukraine