Related papers: Constraining properties of dusty environments by i…
ISO provides a key new far-infrared window through which to observe the multi-wavelength spectral energy distributions (SEDs) of quasars and active galactic nuclei (AGN). It allows us, for the first time, to observe a substantial fraction…
We present calculations of AGN winds at ~parsec scales, along with the associated obscuration. We take into account the pressure of infrared radiation on dust grains and the interaction of X-rays from a central black hole with hot and cold…
The advent of high-angular resolution IR and sub-mm interferometry allows for spatially-resolved observations of the parsec-scale environment of active galactic nuclei (AGN), commonly referred to as the "torus." While molecular lines show…
We construct a generic X-ray spectral model for the reflection component from the clumpy torus and dusty gas in the polar region (polar dusty gas) in an active galactic nucleus (AGN), designated as Inclusive spectral energy distribution…
We investigate models for the power supply and broad-band spectral energy distribution (SED) of hyperluminous IR galaxies, recently discovered at high redshifts, in terms of the emission from an active nucleus embedded in a torus-like dusty…
We use mid-infrared spectroscopy of unobscured active galactic nuclei (AGNs) to reveal their native dusty environments. We concentrate on Seyfert 1 galaxies, observing a sample of 31 with the Infrared Spectrograph aboard the Spitzer Space…
It is widely assumed that long-wavelength infrared (IR) emission from cold dust (T~20-40K) is a reliable tracer of star formation even in the presence of a bright active galactic nucleus (AGN). Based on radiative transfer (RT) models of…
Obscured AGNs provide an opportunity to study the material surrounding the central engine. Geometric and physical constraints on the absorber can be deduced from the reprocessed AGN emission. In particular, the obscuring gas may reprocess…
We present spectroscopic results for all galaxies observed with the Spitzer Infrared Spectrograph (IRS) which also have total infrared fluxes f(ir) measured with the Infrared Astronomical Satellite (IRAS), also using AKARI photometry when…
How do active galactic nuclei with low optical luminosities produce powerful radio emission? Recent studies of active galactic nuclei with moderate radio and low optical luminosities (Fanaroff & Riley class I, FR I) searching for broad…
The unified model of active galactic nuclei (AGN) includes a toroidal obscuring structure to explain the differences between Type I and Type II AGN as an effect of inclination angle. This toroidal structure is thought to be 'clumpy' as the…
Substantial evidence points to dusty, geometrically thick tori obscuring the central engines of active galactic nuclei (AGNs), but so far no mechanism satisfactorily explains why cool dust in the torus remains in a puffy geometry.…
Several models of nuclear dust in active galactic nuclei (AGN) have been presented in the literature to determine its physical and geometrical properties, usually assuming the dust density distribution as the main aspect producing…
We use photometric and spectroscopic infrared observations obtained with the Spitzer Space Telescope of 12 radio-loud active galactic nuclei (AGN) to investigate the dust geometry. Our approach is to look at the change of the infrared…
Infrared studies of asymptotic giant branch (AGB) stars are critical to our understanding of the formation of cosmic dust. In this investigation, we explore the mid-to-far-infrared emission of oxygen rich AGB star RT Virginis. This…
We fitted Spitzer/IRS ~2-35 um spectra of 26 luminous QSOs in 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…
A wide range of stellar explosions, including supernovae (SNe), tidal disruption events (TDE), and fast blue optical transients (FBOT), can occur in dusty environments initially opaque to the transient's optical/UV light, becoming visible…
We have performed 23 GHz VLA observations of 7 compact, luminous infrared galaxies, selected to have evidence of starburst activity. New and published multi-frequency data are combined to obtain the spectral energy distributions of all 7…
Using the multi-epoch mid-infrared (MIR) photometry from the Wide-field Infrared Survey Explorer spanning a baseline of $\sim10$ yr, we extensively investigate the MIR variability of nearby active galactic nuclei (AGNs) at $0.15 < z < 0.4$.…
We construct an X-ray spectral model for the clumpy torus in an active galactic nucleus (AGN) using Geant4, which includes the physical processes of the photoelectric effect, Compton scattering, Rayleigh scattering, $\gamma$ conversion,…