NuSTAR observations of the powerful radio-galaxy Cygnus A
We present NuSTAR observations of the powerful radio galaxy Cygnus A, focusing on the central absorbed active galactic nucleus (AGN). Cygnus A is embedded in a cool-core galaxy cluster, and hence we also examine archival XMM-Newton data to facilitate the decomposition of the spectrum into the AGN and intracluster medium components. NuSTAR gives a source-dominated spectrum of the AGN out to >70 keV. In gross terms, the NuSTAR spectrum of the AGN has the form of a power law (Γ∼1.6−1.7) absorbed by a neutral column density of N{sub H}∼1.6×10{sup 23} cm{sup −2}. However, we also detect curvature in the hard (>10 keV) spectrum resulting from reflection by Compton-thick matter out of our line of sight to the X-ray source. Compton reflection, possibly from the outer accretion disk or obscuring torus, is required even permitting a high-energy cut off in the continuum source; the limit on the cut-off energy is E{sub cut}>111 keV(90% confidence). Interestingly, the absorbed power law plus reflection model leaves residuals suggesting the absorption/emission from a fast (15,000−26,000 km s{sup −1} ), high column-density (N{sub W}>3×10{sup 23} cm{sup −2}), highly ionized (ξ∼2500 erg cm s{sup −1}) wind. A second, even faster ionized wind component is also suggested by these data. We show that the ionized wind likely carries a significant mass and momentum flux, and may carry sufficient kinetic energy to exercise feedback on the host galaxy. If confirmed, the simultaneous presence of a strong wind and powerful jets in Cygnus A demonstrates that feedback from radio-jets and sub-relativistic winds are not mutually exclusive phases of AGN activity but can occur simultaneously.