Seminario DAS // "A chromatic investigation into the cores of active galaxies"

Speaker: Dr. James Leftley
Affiliation: European Southern Observatory (ESO, Chile)

Abstract: "We have long since known that the central parsecs of Active Galactic Nuclei (AGN) contain influential dusty structures which act as the material reservoir for the accreting black hole and contribute to the diversity of AGN spectral types we observe. Despite their key role in AGN physics and spectral unification, these dusty structures have only recently been directly observed as they were impossible to angularly resolve until the advent of long baseline optical interferometry. These breakthrough observations revealed complex parsec scale dusty structures including outflowing dusty winds that could be one way AGN influence the evolution of galaxies. However, these studies were extremely limited in recoverable detail, wavelength range, and most importantly they were limited to just a handful of bright local targets. In the last few years there has been vast improvements in optical interferometric instrumentation.

With this new instrumentation, we can now start to create detailed chromatic images of these structures for a significantly larger sample of AGN. However, this unprecedented detail brings new and unique challenges in interpretation. I will present an overview of how our understanding of the dusty structures in the central parsecs of AGN has changed in recent years followed by our own attempts to build a more complete chromatic model of this region using new instrumentation at the Very Large Telescope Interferometer (VLTI). I will demonstrate and discuss what this means for galaxy evolution and studies of active galaxies with instrumentation such as JWST and the ELT."