Spatially Resolved Mid-Infrared Spectroscopy of NGC 1068: The Nature and Distribution of the Nuclear Material

摘要: We present spatially resolved, near-diffraction-limited 10 μm spectra of the nucleus Seyfert 2 galaxy NGC 1068, obtained with Michelle, mid-IR imager and spectrometer on 8.1 m Gemini North Telescope. The cover central 60 × 04 ionization cones at a spatial resolution approximately (≈30 pc). extracted in steps along slit reveal striking variations continuum slope, silicate feature profile depth, fine-structure line fluxes subarcsecond scales, illustrating unprecedented detail complexity circumnuclear regions 1068 wavelengths. A comparison photometry various apertures reveals two distinct components: compact (radius < 15 pc), bright source within extended, lower brightness emission. identify AGN-obscuring torus, diffuse component dust cones. While torus emission dominates flux observed near-IR, measured larger than about 1'' is dominated instead by from cones; despite its higher brightness, contributes <30% 11.6 12 region. Many previous attempts to determine spectral energy distribution are thus likely be significantly affected contamination extended spectrum compared clumpy models. models require most clouds located few parsecs engine, agreement recent interferometric observations. also UKIRT/CGS4 5 covering R(0)-R(4) lines fundamental vibration-rotation band 12CO. None these was detected, we discuss nondetections terms filling factor composition nuclear clouds.