Physical Sciences and Mathematics Commons^™

Deciphering The Arrangement Of Dust In The Clumpy Tori Of Active Galactic Nuclei, Grant David Thompson

Theses and Dissertations--Physics and Astronomy

In the framework of active galactic nuclei (AGNs), a galaxy’s supermassive black hole is surrounded by a dusty torus whose clumpy configuration allows for either direct or obscured views toward the central engine. Viewing AGNs from different angles gives rise to a variety of AGN classifications; for example, the generic Type 1 AGN class requires the detection of optically broad emission lines, which arise from quickly moving material within the torus, whereas Type 2 AGNs lack these observations. While these viewing angles are not directly observable, synthetic torus models generated with CLUMPY provide a means to determine them along with …

Obscuration In Active Galactic Nuclei, Robert Nikutta

Theses and Dissertations--Physics and Astronomy

All classes of Active Galactic Nuclei (AGN) are fundamentally powered by accretion of gas onto a supermassive black hole. The process converts the potential energy of the infalling matter to X-ray and ultraviolet (UV) radiation, releasing up to several 10¹² solar luminosities.

Observations show that the accreting "central engines" in AGN are surrounded by dusty matter. The dust occupies a "torus" around the AGN which is comprised of discrete clumps. If the AGN radiation is propagating through the torus on its way to an observer, it will be heavily re-processed by the dust, i.e. converted from UV to infrared …