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Intergalactic Extinction and the Quasar Cut‐off
Author(s) -
Oleak H.,
Schmidt K.H.
Publication year - 1976
Publication title -
astronomische nachrichten
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.394
H-Index - 63
eISSN - 1521-3994
pISSN - 0004-6337
DOI - 10.1002/asna.19762970203
Subject(s) - quasar , intergalactic travel , astrophysics , physics , extinction (optical mineralogy) , redshift , intergalactic dust , intergalactic medium , absolute magnitude , luminosity , lyman alpha forest , astronomy , galaxy , optics
The intergalactic extinction in FRIEDMANN (with A = o) universes homogeneously filled with dust grains is calculated assuming the extinction to be 0.5 mag at z = 1 and a λ −1 wavelength dependence. With the resulting intergalactic extinction the number of quasars which should be observed at different redshifts are estimated assuming two different luminosity functions and a density evolution of the quasars according to M. SCHMIDT (1970, 1972). The expected number of quasars decreases rapidly with increasing redshift between z = 2 and z = 3. The observed number‐magnitude relation by G. A. RICHTER (1975) is well represented.