title: Mid-infrared interferometry of AGN cores
creator: Burtscher, Leonard
subject: ddc-520
subject: 520 Astronomy and allied sciences
description: Active Galactic Nuclei (AGNs) are among the most luminous objects in the universe and are classified into a number of types and subtypes. Unified models of AGNs explain some of this variety as a result of different viewing angles towards their cores instead of intrinsic differences: from some viewing angles, our line of sight would be blocked by a dusty torus. The spatial resolution necessary to resolve these warm dust structures at 10 micron is currently only provided by the Very Large Telescope Interferometer (VLTI) in Chile. First, extensive observations of the radio galaxy Centaurus A are examined that show an extended structure, which is probably connected to the Northern nuclear radio jet, at a distance of about 40 milli arcseconds (0.7 parsec) in front of the nucleus. Secondly, a study of the brightest so-called type 1 Seyfert galaxy, NGC 4151, reveals for the first time a resolved nuclear emitter in such a source. Its properties (size, temperature profile, emissivity) are similar to those of the alternative type 2 galaxies, studied previ- ously. This is consistent with, though not necessarily confirmation of, unified models. Since the previous studies of type 2 source and modern torus models show a wide variety of nuclear dust structures, finally, the so-far most comprehensive study of resolved nuclear dust emission of AGNs is set up to study 13 AGNs of various luminosities L and distances reaching several hundred Mega Parsec. The first full analysis of this study shows in all but one galaxy that tori can be resolved and that their size on parsec scales is not simply proportional to L^0.5.
date: 2011
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/12037/1/burtscher2011_mid_infrared_interferometry_of_agn_cores.pdf
identifier: DOI:10.11588/heidok.00012037
identifier: urn:nbn:de:bsz:16-opus-120370
identifier:   Burtscher, Leonard  (2011) Mid-infrared interferometry of AGN cores.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/12037/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng