Browsing University of Hertfordshire by Author "Kalfountzou, E."

Now showing items 1-3 of 3

    • Herschel-ATLAS: Far-infrared properties of radio-loud and radio-quiet quasars 

      Kalfountzou, E.; Stevens, J.A.; Jarvis, M.J.; Hardcastle, M.J.; Smith, Daniel; Bourne, N.; Dunne, L.; Ibar, E.; Eales, S.; Ivison, R.J.; Maddox, S.; Smith, M. W. L.; Valiante, E.; de Zotti, G. (2014-08-01)
      We have constructed a sample of radio-loud and radio-quiet quasars from the Faint Images Radio Sky at Twenty-one centimetres and the Sloan Digital Sky Survey Data Release 7, over the Herschel-ATLAS Phase 1 area (9h, 12h ...

    • Observational evidence that positive and negative AGN feedback depends on galaxy mass and jet power 

      Kalfountzou, E.; Stevens, J. A.; Jarvis, M. J.; Hardcastle, M. J.; Wilner, D.; Elvis, M.; Page, M. J.; Trichas, M.; Smith, D. J. B. (2017-10-11)
      Several studies support the existence of a link between the AGN and star formation activity. Radio jets have been argued to be an ideal mechanism for direct interaction between the AGN and the host galaxy. A drawback of ...

    • Star formation in high-redshift quasars : Excess [Oii] emission in the radio-loud population 

      Kalfountzou, E.; Jarvis, M.J.; Bonfield, D.G.; Hardcastle, M.J. (2012-12-11)
      We investigate the [O ii] emission-line properties of 18 508 quasars at z < 1.6 drawn from the Sloan Digital Sky Survey (SDSS) quasar sample. The quasar sample has been separated into 1692 radio-loud and 16 816 radio-quiet ...