Radio Emission of Cygnus X-2

Abstract

Moffet and Berge¹ recently reported an attempt to detect radio emission from the X-ray source Cygnus X-2. They observed with an interferometer at a wavelength of 3.12 cm and found evidence of a radio source of flux density 0.05 ± 0.03 flux units (1 flux unit = 10⁻²⁶ W m⁻² Hz⁻¹). Although the signal-to-noise ratio was low, the phase of the interferometer output agreed well with that expected. Also, observations at 10.6 cm showed compatible, though inconclusive, results. They therefore suggested that there might be a faint radio source at the position of the X-ray object, although they recognized that the source could be spurious.