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2006

University of Kentucky

Physics and Astronomy Faculty Publications

ISM: Dust

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Spatially Resolved Mid-Infrared Spectroscopy Of Ngc 1068: The Nature And Distribution Of The Nuclear Material, R. E. Mason, T. R. Geballe, C. Packham, N. A. Levenson, Moshe Elitzur, R. S. Fisher, E. Perlman Apr 2006

Spatially Resolved Mid-Infrared Spectroscopy Of Ngc 1068: The Nature And Distribution Of The Nuclear Material, R. E. Mason, T. R. Geballe, C. Packham, N. A. Levenson, Moshe Elitzur, R. S. Fisher, E. Perlman

Physics and Astronomy Faculty Publications

We present spatially resolved, near-diffraction-limited 10 μm spectra of the nucleus of the Seyfert 2 galaxy NGC 1068, obtained with Michelle, the mid-IR imager and spectrometer on the 8.1 m Gemini North Telescope. The spectra cover the nucleus and the central 6.0” × 0.4” of the ionization cones at a spatial resolution of approximately 0.4” (≈30 pc). The spectra extracted in 0.4” steps along the slit reveal striking variations in continuum slope, silicate feature profile and depth, and fine-structure line fluxes on subarcsecond scales, illustrating in unprecedented detail the complexity of the circumnuclear regions of NGC 1068 at mid-IR …


Near-Infrared And The Inner Regions Of Protoplanetary Disks, Dejan Vinković, Željko Ivezić, Tomislav Jurkić, Moshe Elitzur Jan 2006

Near-Infrared And The Inner Regions Of Protoplanetary Disks, Dejan Vinković, Željko Ivezić, Tomislav Jurkić, Moshe Elitzur

Physics and Astronomy Faculty Publications

We examine the “puffed-up inner disk” model proposed by Dullemond, Dominik, & Natta for explaining the near-IR excess radiation from Herbig Ae/Be stars. Detailed model computations show that the observed near-IR excess requires more hot dust than is contained in the puffed-up disk rim. The rim can produce the observed near-IR excess only if its dust has perfectly gray opacity, but such dust is in conflict with the observed 10 μm spectral feature. We find that a compact (~10 AU), tenuous (τV ≲ 0.4), dusty halo around the disk inner regions contains enough dust to readily explain …