A mid-infrared statistical investigation of clumpy torus model predictions

Abstract

We present new calculations of the CAT3D clumpy torus models, which now include a more physical dust sublimation model as well as AGN anisotropic emission. These new models allow graphite grains to persist at temperatures higher than the silicate dust sublimation temperature. This produces stronger near-infrared emission and bluer mid-infrared (MIR) spectral slopes. We make a statistical comparison of the CAT3D model MIR predictions with a compilation of sub-arcsecond resolution ground-based MIR spectroscopy of 52 nearby Seyfert galaxies (median distance of 36 Mpc) and 10 quasars. We focus on the AGN MIR spectral index ${\alpha }_{MIR}$ and the strength of the 9.7 $\mu$m silicate feature $S_{Sil}$. As with other clumpy torus models, the new CAT3D models do not reproduce the Seyfert galaxies with deep silicate absorption ($S_{Sil}<-1$). Excluding those, we conclude that the new CAT3D models are in better agreement with the observed ${\alpha }_{MIR}$ and $S_{Sil}$ of Seyfert galaxies and quasars. We find that Seyfert 2 are reproduced with models with low photon escape probabilities, while the quasars and the Seyfert 1-1.5 require generally models with higher photon escape probabilities. Quasars and Seyfert 1-1.5 tend to show steeper radial cloud distributions and fewer clouds along an equatorial line-of-sight than Seyfert 2. Introducing AGN anisotropic emission besides the more physical dust sublimation models alleviates the problem of requiring inverted radial cloud distributions (i.e., more clouds towards the outer parts of the torus) to explain the MIR spectral indices of type 2 Seyferts.

23 pages, 17 figures, 5 tables, Accepted for publication in MNRAS

References in corpus (22)

• AGN Dusty Tori: I. Handling of Clumpy Media
• Swift BAT Survey of AGN
• Radiative Transfer Modeling of Three-Dimensional Clumpy AGN Tori and its Application to NGC 1068
• The innermost region of AGN tori: implications from the HST/NICMOS Type 1 point sources and near-IR reverberation
• Three-dimensional radiative transfer models of clumpy tori in Seyfert galaxies
• The Infrared Nuclear Emission of Seyfert Galaxies on Parsec Scales: Testing the Clumpy Torus models
• 9.7 um Silicate Features in AGNs: New Insights into Unification Models
• High-Velocity Bipolar Molecular Emission from an AGN Torus
• Parsec-scale dust distributions in Seyfert galaxies - Results of the MIDI AGN snapshot survey
• Nuclear 11.3$\mu$m PAH emission in local active galactic nuclei
• On the difference of torus geometry between hidden and non-hidden broad line active galactic nuclei
• Silicates in Ultra-Luminous Infrared Galaxies
• Obscuration in AGNs: near-infrared luminosity relations and dust colors
• Resolving the AGN and host emission in the mid-infrared using a model-independent spectral decomposition
• On the LINER nuclear obscuration, Compton-thickness and the existence of the dusty torus; Clues from Spitzer/IRS spectra
• A complete census of silicate features in the mid-infrared spectra of active galaxies
• Silicate absorption in heavily obscured galaxy nuclei
• Probing the Active Galactic Nuclei Unified Model Torus Properties in Seyfert Galaxies
• The nuclear and extended mid-infrared emission of Seyfert galaxies
• The dusty tori of nearby QSOs as constrained by high-resolution mid-IR observations
• The silicate absorption profile in the ISM towards the heavily obscured nucleus of NGC 4418
• The complex evolutionary paths of local infrared bright galaxies: a high angular resolution mid-infrared view

Cited by in corpus (12)

• The Galaxy Activity, Torus and Outflow Survey (GATOS): II. Torus and polar dust emission in nearby Seyfert galaxies
• Torus model properties of an ultra-hard X-ray selected sample of Seyfert galaxies
• Compton-thick AGN in the NuSTAR era III: A systematic study of the torus covering factor
• Infrared Spectral Energy Distribution and Variability of Active Galactic Nuclei: Clues to the Structure of Circumnuclear Material
• Testing the Evolutionary Link between Type 1 and Type 2 Quasars with Measurements of the Interstellar Medium
• Torus and polar dust dependence on AGN properties
• X-ray absorption in INTEGRAL AGN: Host galaxy inclination
• Modelling the strongest silicate emission features of local type 1 AGN
• Blazar Sheath Illumination of the Outer Molecular Torus: A Resolution of the Seed Photon Problem for the far-GeV Blazar flares
• The complex infrared dust continuum emission of NGC1068: ground-based N- and Q-band spectroscopy and new radiative transfer models
• Dynamical model of an obscuring clumpy torus in AGNs: I. Velocity and velocity dispersion maps for interpretation of ALMA observations
• Orientation effects on the near-infrared broad band emission of quasars