Structure and kinematics of the interstellar medium around WR 142a: Searching for traces of the action of stellar wind

Abstract

Based on our Hα interferometric observations and CO data, we analyze the structure and kinematics of the gas in an extended region of the Cygnus arm around the recently discovered star WR 142a. We have established that WR 142a and the ionized hydrogen in its immediate neighborhood are associated with the complex of molecular clouds observed in a region with l ∼ 78°–80°30′, b ∼ 2°–3°20′, and V _LSR ∼ 4–16 km s⁻¹. Traces of the action of the stellar wind from WR 142a on the ambient gas have been found to the northeast of the star in a region devoid of dense absorbing foreground clouds. These include very weak thin gas and dust filaments as well as high-velocity components of the Hα profile, which can be interpreted as a possible expansion of the shell swept up by the wind with a velocity as high as 50–80 km s⁻¹. Giant regions of reduced CO emission dominated by high-velocity motions of ionized hydrogen have been detected. Stars of the Cyg OB2 association and the cluster NGC 6910 can be responsible for these motions.