{"id":{"repo_id":"heid-diss","oai_identifier":"oai:archiv.ub.uni-heidelberg.de:2114"},"canonical_url":"https://search.dev.ndltd.org/etd/heid-diss/oai:archiv.ub.uni-heidelberg.de:2114","repository":{"repo_id":"heid-diss","name":"Universität Heidelberg","base_url":"http://archiv.ub.uni-heidelberg.de/volltextserver/cgi/oai2"},"display":{"title":"On the Interaction of Jets with the Dense Medium of the Early Universe","abstract":"In recent years, radio galaxies have been found at redshifts above five. They differ in higher radio power and emission line characteristics from sources nearby. To understand these centers of proto-galaxy-clusters, hydrodynamic jets with cooling were simulated. After validation of the 3D code NIRVANA by comparison with literature simulations, an adiabatic 2D parameter study in the relevant regime (density contrast jet/medium eta=10^{-2}-10^{-5} was performed. Characteristic cocoon shape and broadenings were found. The radial expansion can be analytically approximated by a spherical blast wave with constant energy injection. In a non-equilibrium simulation the bow shock cooled to 10^4 K during jet propagation time (external density 1 ccm. After global cooling and compression, the bow shock turned into a big absorber which fragmented, and should form stars in typically 10^4 globular clusters of 10^6 solar masses. Filamentation and fragmentation was confirmed at high resolution. Absorbers in far-off radio galaxies and globular cluster excesses in nearby CD galaxies can be explained that way. With literature parameters fo Cygnus~A, a 3D simulation, for the first time with counter-jet, was performed. The bow shock shows two clearly separated phases, also evident in observation. Basic jet parameters have been derived. The simulation shows characteristic X-ray features (rings) which were identified and interpreted in two sources (M87).","abstract_html":"In recent years, radio galaxies have been found at redshifts above five. They differ in higher radio power and emission line characteristics from sources nearby. To understand these centers of proto-galaxy-clusters, hydrodynamic jets with cooling were simulated. After validation of the 3D code NIRVANA by comparison with literature simulations, an adiabatic 2D parameter study in the relevant regime (density contrast jet/medium eta=10^{-2}-10^{-5} was performed. Characteristic cocoon shape and broadenings were found. The radial expansion can be analytically approximated by a spherical blast wave with constant energy injection. In a non-equilibrium simulation the bow shock cooled to 10^4 K during jet propagation time (external density 1 ccm. After global cooling and compression, the bow shock turned into a big absorber which fragmented, and should form stars in typically 10^4 globular clusters of 10^6 solar masses. Filamentation and fragmentation was confirmed at high resolution. Absorbers in far-off radio galaxies and globular cluster excesses in nearby CD galaxies can be explained that way. With literature parameters fo Cygnus~A, a 3D simulation, for the first time with counter-jet, was performed. The bow shock shows two clearly separated phases, also evident in observation. Basic jet parameters have been derived. The simulation shows characteristic X-ray features (rings) which were identified and interpreted in two sources (M87).","abstract_has_math":false,"creators":["Krause, Martin"],"institution":"Universität Heidelberg","degree_name":null,"degree_level":"thesis.doctoral","degree_discipline":null,"degree_department":null,"school":null,"contributors":["Camenzind, Max"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2002,"date_issued":"2002-05-15","date_published":"2002-05-15","updated_at":"2026-07-24T02:29:18Z","subjects":[],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://www.ub.uni-heidelberg.de/archiv/2114","outbound_label":"Repository record","outbound_source":"source_url"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Camenzind, Max"]},{"key":"dc:creator","label":"Author","values":["Krause, Martin"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:publisher","label":"Institution","values":["Universitätsbibliothek Heidelberg"]},{"key":"dc:type","label":"Dc Type","values":["doctoralThesis"]},{"key":"thesis:degree_level","label":"Degree Level","values":["thesis.doctoral"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Universität Heidelberg"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["In recent years, radio galaxies have been found at redshifts above five. They differ in higher radio power and emission line characteristics from sources nearby. To understand these centers of proto-galaxy-clusters, hydrodynamic jets with cooling were simulated. After validation of the 3D code NIRVANA by comparison with literature simulations, an adiabatic 2D parameter study in the relevant regime (density contrast jet/medium eta=10^{-2}-10^{-5} was performed. Characteristic cocoon shape and broadenings were found. The radial expansion can be analytically approximated by a spherical blast wave with constant energy injection. In a non-equilibrium simulation the bow shock cooled to 10^4 K during jet propagation time (external density 1 ccm. After global cooling and compression, the bow shock turned into a big absorber which fragmented, and should form stars in typically 10^4 globular clusters of 10^6 solar masses. Filamentation and fragmentation was confirmed at high resolution. Absorbers in far-off radio galaxies and globular cluster excesses in nearby CD galaxies can be explained that way. With literature parameters fo Cygnus~A, a 3D simulation, for the first time with counter-jet, was performed. The bow shock shows two clearly separated phases, also evident in observation. Basic jet parameters have been derived. The simulation shows characteristic X-ray features (rings) which were identified and interpreted in two sources (M87)."]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["On the Interaction of Jets with the Dense Medium of the Early Universe","Ueber die Wechselwirkung von Jets mit dem dichten Medium des fruehen Universums"]}]}],"canonical_facts":{"dc:contributor":["Camenzind, Max"],"dc:creator":["Krause, Martin"],"dc:description.abstract":["In recent years, radio galaxies have been found at redshifts above five. They differ in higher radio power and emission line characteristics from sources nearby. To understand these centers of proto-galaxy-clusters, hydrodynamic jets with cooling were simulated. After validation of the 3D code NIRVANA by comparison with literature simulations, an adiabatic 2D parameter study in the relevant regime (density contrast jet/medium eta=10^{-2}-10^{-5} was performed. Characteristic cocoon shape and broadenings were found. The radial expansion can be analytically approximated by a spherical blast wave with constant energy injection. In a non-equilibrium simulation the bow shock cooled to 10^4 K during jet propagation time (external density 1 ccm. After global cooling and compression, the bow shock turned into a big absorber which fragmented, and should form stars in typically 10^4 globular clusters of 10^6 solar masses. Filamentation and fragmentation was confirmed at high resolution. Absorbers in far-off radio galaxies and globular cluster excesses in nearby CD galaxies can be explained that way. With literature parameters fo Cygnus~A, a 3D simulation, for the first time with counter-jet, was performed. The bow shock shows two clearly separated phases, also evident in observation. Basic jet parameters have been derived. The simulation shows characteristic X-ray features (rings) which were identified and interpreted in two sources (M87)."],"dc:format.medium":["application/pdf"],"dc:publisher":["Universitätsbibliothek Heidelberg"],"dc:title":["On the Interaction of Jets with the Dense Medium of the Early Universe","Ueber die Wechselwirkung von Jets mit dem dichten Medium des fruehen Universums"],"dc:type":["doctoralThesis"],"thesis:degree_level":["thesis.doctoral"],"thesis:institution_name":["Universität Heidelberg"]},"updated_at":"2026-07-24T02:29:18Z"}