Chandra HRC and HST observations of NGC 6240: Resolving the active galactic nucleus and starburst

Abstract

We present high spatial resolution X-ray Chandra HRC and HST WFPC2 Ha observations of the prototypical infrared-luminous galaxy NGC 6240. The central region of this system shows a remarkably complex morphology, with filaments and loops observed in the optical and X-rays. The total X-ray luminosity is dominated by the extended emission. Both nuclei are clearly detected in the HRC image and both appear to be extended. The energetics of the nuclei imply that the southern nucleus is the more plausible counterpart to the obscured active galactic nucleus. The overall spectral energy distribution of the galaxy is in good agreement with a blend of starburst and AGN components that have similar bolometric luminosities, Lbol ∼ 5 × 1045 erg s-1, with the starburst dominating the observed continuum in the nearinfrared (K band), optical and soft X-ray bands.