1995A&A...296..201S

We present coronal iron line observations of the Cygnus Loop Supernova Remnant (SNR). We describe and analyse the measurements obtained with the new Fabry-Perot spectrophotometer, E.S.O.P., in the [FeX] and [FeXIV] coronal lines. The spectral capability of the instrument allows to study the kinematics of the 10⁶K hot gas. We extensively observed the north X-ray irregularity of the Cygnus Loop, which appears as a large V with a central extended condensation located roughly at (α₁₉₅₀≃20h48min, δ₁₉₅₀≃32deg00'). These results are the first measurements of the X-ray gas velocity along the observed V-shaped feature: the east arm is associated with red shifted gas while the west arm is blue shifted. This structure can thus be simply interpreted as a projection effect without involving a bow shock or intersecting shocks.