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A search for homogeneous samples of quasars

  • Volker Gericke
V Quasars
Part of the Lecture Notes in Physics book series (LNP, volume 310)

Abstract

An automated search for quasars, based on MRSP software, is applied to low-dispersion objective prism plates. Two criteria are used. The first criterion is the UV excess of low and medium redshift quasars. The second criterion is the presence of emission lines. 25 000 non-overlapping spectra in the ESO/SRC field No. 411 were analyzed; 600 show UV excess, 2 500 spectra have apparent emission lines. Both criteria taken separately lead to a large number of “false” objects. In the combined feature space known quasars occupy a characteristic region. Among the objects from this region in the limited magnitude range 18m – 19m 600 quasar candidates were found. Redshifts were determined from the low-dispersion objective prism spectra for 255 of these objects. The spatial distribution of 158 Ly α quasars is discussed.

Keywords

Emission Line Homogeneous Sample Emission Feature Magnitude Range Objective Prism 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag 1988

Authors and Affiliations

  • Volker Gericke
    • 1
  1. 1.Astronomisches InstitutWestfälische Wilhelms-UniversitätMünsterF.R. Germany

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