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Full-Text Articles in Physics
Dusty Structure Around Type-I Active Galactic Nuclei: Clumpy Torus Narrow-Line Region And Near-Nucleus Hot Dust, Rivay Mor, Hagai Netzer, Moshe Elitzur
Dusty Structure Around Type-I Active Galactic Nuclei: Clumpy Torus Narrow-Line Region And Near-Nucleus Hot Dust, Rivay Mor, Hagai Netzer, Moshe Elitzur
Physics and Astronomy Faculty Publications
We fitted Spitzer/IRS ~ 2-35 μm spectra of 26 luminous quasi-stellar objects in an attempt to define the main emission components. Our model has three major components: a clumpy torus, dusty narrow-line region (NLR) clouds, and a blackbody-like dust. The models utilize the clumpy torus of Nenkova et al. and are the first to allow its consistent check in type-I active galactic nuclei (AGNs). Single torus models and combined torus-NLR models fail to fit the spectra of most sources, but three-component models adequately fit the spectra of all sources. We present torus inclination, cloud distribution, covering factor, and …
Detections Of Water Ice, Hydrocarbons, And 3.3 ΜM Pah In Z ~ 2 Ulirgs, Anna Sajina, Henrik Spoon, Lin Yan, Masatoshi Imanishi, Dario Fadda, Moshe Elitzur
Detections Of Water Ice, Hydrocarbons, And 3.3 ΜM Pah In Z ~ 2 Ulirgs, Anna Sajina, Henrik Spoon, Lin Yan, Masatoshi Imanishi, Dario Fadda, Moshe Elitzur
Physics and Astronomy Faculty Publications
We present the first detections of the 3 μm water ice and 3.4 μm amorphous hydrocarbon (HAC) absorption features in z ~ 2 ULIRGs. These are based on deep rest-frame 2-8 μm Spitzer Infrared Spectrograph spectra of 11 sources selected for their appreciable silicate absorption. The HAC-to-silicate ratio for our z ~ 2 sources is typically higher by a factor of 2-5 than that observed in the Milky Way. This HAC “excess” suggests compact nuclei with steep temperature gradients as opposed to predominantly host obscuration. Beside the above molecular absorption features, we detect the 3.3 μm …
Collisional Heating As The Origin Of Filament Emission In Galaxy Clusters, G. J. Ferland, A. C. Fabian, N. A. Hatch, R. M. Johnstone, R. L. Porter, P. A. M. Vanhoof, R. J. R. Williams
Collisional Heating As The Origin Of Filament Emission In Galaxy Clusters, G. J. Ferland, A. C. Fabian, N. A. Hatch, R. M. Johnstone, R. L. Porter, P. A. M. Vanhoof, R. J. R. Williams
Physics and Astronomy Faculty Publications
It has long been known that photoionization, whether by starlight or other sources, has difficulty in accounting for the observed spectra of the optical filaments that often surround central galaxies in large clusters. This paper builds on the first of this series in which we examined whether heating by energetic particles or dissipative magnetohydrodynamic (MHD) wave can account for the observations. The first paper focused on the molecular regions which produce strong H2 and CO lines. Here we extend the calculations to include atomic and low-ionization regions. Two major improvements to the previous calculations have been made. The model …