A&A 424, 73-78 (2004)
DOI: 10.1051/0004-6361:20040567
Influence of a generalized Eddington bias on galaxy counts
P. TeerikorpiTuorla Observatory, University of Turku, 21500 Piikkiö, Finland
e-mail: pekkatee@utu.fi
(Received 31 March 2004 / Accepted 11 May 2004)
Abstract
We study the influence of the Eddington bias on measured
distributions, in particular counts of galaxies when the accuracy of
magnitude measurements is variable, e.g. when it changes towards fainter
objects.
Numerical experiments using different error laws illustrate the effect
on the measured slope, helping one to decide if the variable Eddington
bias is important, when the simple analytic correction is no longer valid.
Common views on the origin and appearance of the Eddington bias are
clarified and its relation to the classical Malmquist bias is briefly
discussed. We illustrate the "Eddington shift" approach with the counts
of bright galaxies in the LEDA database.
Key words: galaxies: statistics
© ESO 2004
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