Searches for the shell swept up by the stellar wind from Cyg OB2

We investigated the kinematics of ionized gas in an extended (20°×15°) region containing the X-ray Superbubble in Cygnus with the aim of finding the shell swept up by a strong wind from Cyg OB2. Hα observations were carried out with high angular and spectral resolutions using a Fabry-Perot interferometer attached to the 125-cm telescope at the Crimean Observatory of the Sternberg Astronomical Institute. We detected high-velocity gas motions, which could result from the expansion of the hypothetical shell at a velocity of 25–50 km s−1. Given the number of OB stars increased by Knödlseder (2000) by an order of magnitude, Cyg OB2 is shown to possess a wind that is strong enough [Lw ≃ (1–2) × 1039 erg s−1] to produce a shell comparable in size to the X-ray Superbubble and to a giant system of optical filaments. Based on our measurements and on X-ray and infrared observations, we discuss possible observational manifestations of the shell swept up by the wind.