Cold gas & mergers: fundamental difference in HI properties of different types of radio galaxies?

dc.creatorEmonts, Bjorn
dc.creatorMorganti, Raffaella
dc.creatorOosterloo, Tom
dc.creatorvan Gorkom, Jacqueline
dc.date2008-01-30
dc.date.accessioned2026-07-07T08:57:25Z
dc.date.available2026-07-07T08:57:25Z
dc.descriptionWe present results of a study of large-scale neutral hydrogen (HI) gas in nearby radio galaxies. We find that the early-type host galaxies of different types of radio sources (compact, FR-I and FR-II) appear to contain fundamentally different large-scale HI properties: enormous regular rotating disks and rings are present around the host galaxies of a significant fraction of low power compact radio sources, while no large-scale HI is detected in low power, edge-darkened FR-I radio galaxies. Preliminary results of a study of nearby powerful, edge-brightened FR-II radio galaxies show that these systems generally contain significant amounts of large-scale HI, often distributed in tail- or bridge-like structures, indicative of a recent galaxy merger or collision. Our results suggest that different types of radio galaxies may have a different formation history, which could be related to a difference in the triggering mechanism of the radio source. If confirmed by larger studies with the next generation radio telescopes, this would be in agreement with previous optical studies that suggest that powerful FR-II radio sources are likely triggered by galaxy mergers and collisions, while the lower power FR-I sources are fed in other ways (e.g. through the accretion of hot IGM). The giant HI disks/rings associated with some compact sources could - at least in some cases - be the relics of much more advanced mergers.
dc.description5 pages, 3 figures - to appear in PoS, "The Modern Radio Universe: From Planets to Dark Energy Conference", Manchester UK, eds: Beswick, Diamond & Schilizzi
dc.identifierhttps://arxiv.org/abs/0801.4769
dc.identifierhttp://arxiv.org/abs/0801.4769
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/146964
dc.subjectAstrophysics
dc.titleCold gas & mergers: fundamental difference in HI properties of different types of radio galaxies?
dc.typetext

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