Definition of Volume Limited Sample for Sky Surveys

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A volume limited sample in sky surveys refers to a selection of galaxies within a specific redshift range, ensuring that only those meeting certain brightness criteria are included. This approach is necessary because surveys often miss fainter galaxies as redshift increases due to limited precision. The discussion highlights the distinction between absolute and apparent brightness, clarifying that a volume limited sample typically involves absolute brightness. The need for a precise definition of this concept is emphasized, as it is crucial for accurately cataloging galaxies in astronomical surveys. Understanding these parameters is essential for effective data interpretation in galaxy surveys.
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Does anybody have a link to a precise definition of a "volume limited sample." This pertains especially to sky surveys that catalog galaxies. Due to limited precision, surveys tend to miss fainter galaxies as redshift increases. Thus, very loosely, I think, a volume limited sample filters out certain galaxies so that only galaxies of a finite brightness range are considered at all pertinent redshifts. However, I am looking for a precise definition, but can't seem to find one.
 
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A volume limited sample just takes galaxies within a certain redshift range.

Zaphodx57x said:
Thus, very loosely, I think, a volume limited sample filters out certain galaxies so that only galaxies of a finite brightness range are considered at all pertinent redshifts.

Do you mean absolute or apparent brightness? If the latter, this is not a volume limited sample.
 

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