1999/04/19 by Xue-Bing Wu, Wu, Xue-Bing, N. Bade +3
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics (astro-ph) #Astrophysics and Star Formation Studies #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena
paper · pdf · doi:10.48550/arxiv.astro-ph/9904233
openalex publication_date 1999/04/19 · openalex created_date 2019/06/27 · openalex updated_date 2026/07/28
X-ray luminous radio-quiet high redshift QSOs are rare and can be used for\nthe investigation of several important astronomical questions. We have\nconducted a large area survey for radio-quiet high redshift QSOs in the ROSAT\nAll-Sky Survey, from which QSO candidates are selected using the digitized\nobjective prism spectra from the Hamburg Quasar Survey. The 22 candidates with\nGalactic latitudes larger than 35o were observed with the 2.16m telescope at\nXinglong station of Beijing Astronomical Observatory. Among the 19 new QSOs in\nour sample, six are radio-quiet QSOs with redshifts larger than 1.3 and three\nof them have redshifts larger than 2. Thus we have doubled the number of known\nX-ray luminous, radio-quiet high redshift QSOs in the surveyed sky area. The\ndistribution of f1.4GHz/f1keV of radio-loud and radio-quiet QSOs in\nthis area shows two well separated peaks. This can be taken as an evidence for\ndifferent emission mechanisms of the observed X-rays in the two subgroups.\n