dc.contributor.author | Hardcastle, M.J. | |
dc.contributor.author | Evans, D.A. | |
dc.contributor.author | Croston, J.H. | |
dc.date.accessioned | 2007-10-29T12:06:47Z | |
dc.date.available | 2007-10-29T12:06:47Z | |
dc.date.issued | 2006 | |
dc.identifier.citation | Hardcastle , M J , Evans , D A & Croston , J H 2006 , ' The X-ray nuclei of intermediate-redshift radio sources ' , Monthly Notices of the Royal Astronomical Society , vol. 370 , no. 4 , pp. 1893-1904 . https://doi.org/10.1111/j.1365-2966.2006.10615.x | |
dc.identifier.issn | 0035-8711 | |
dc.identifier.other | dspace: 2299/1003 | |
dc.identifier.other | ORCID: /0000-0003-4223-1117/work/30391074 | |
dc.identifier.uri | http://hdl.handle.net/2299/1003 | |
dc.description | The definitive version is available at www.blackwell-synergy.com. Copyright Blackwell Publishing DOI : 10.1111/j.1365-2966.2006.10615.x | |
dc.description.abstract | We present a Chandra and XMM-Newton spectral analysis of the nuclei of the radio galaxies and radio-loud quasars from the 3CRR sample in the redshift range 0.1 < z < 0.5. In the range of radio luminosity sampled by these objects, mostly FRIIs, it has been clear for some time that a population of radio galaxies (‘low-excitation radio galaxies’) cannot easily participate in models that unify narrow-line radio galaxies and broad-line objects. We show that low-excitation and narrow-line radio galaxies have systematically different nuclear Xray properties: while narrow-line radio galaxies universally show a heavily absorbed nuclear X-ray component, such a heavily absorbed component is rarely found in sources classed as low-excitation objects. Combining our data with the results of our earlier work on the z < 0.1 3CRR sources, we discuss the implications of this result for unified models, for the origins of mid-infrared emission from radio sources, and for the nature of the apparent FRI/FRII dichotomy in the X-ray. The lack of direct evidence for accretion-relatedX-ray emission in FRII LERGs leads us to argue that there is a strong possibility that some, or most, FRII LERGs accrete in a radiatively inefficient mode. However, our results are also consistent with a model in which the accretion mode is the same for low- and high-excitation FRIIs, with the lower accretion luminosities in FRII LERGs attributed instead to more efficient radio luminosity production in those objects. | en |
dc.format.extent | 263459 | |
dc.language.iso | eng | |
dc.relation.ispartof | Monthly Notices of the Royal Astronomical Society | |
dc.title | The X-ray nuclei of intermediate-redshift radio sources | en |
dc.contributor.institution | School of Physics, Astronomy and Mathematics | |
dc.contributor.institution | SPECS Deans Group | |
dc.contributor.institution | School of Physics, Engineering & Computer Science | |
dc.contributor.institution | Department of Physics, Astronomy and Mathematics | |
dc.contributor.institution | Centre for Astrophysics Research | |
dc.contributor.institution | Science & Technology Research Institute | |
dc.description.status | Peer reviewed | |
rioxxterms.versionofrecord | 10.1111/j.1365-2966.2006.10615.x | |
rioxxterms.type | Journal Article/Review | |
herts.preservation.rarelyaccessed | true | |