What Is Galaxy 'Completeness'?

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Completeness in astronomical surveys refers to the extent to which the detected data accurately represents the actual distribution of celestial sources. It highlights the limitations of a survey based on the brightness threshold of the telescope, meaning that fainter objects may go undetected. When analyzing luminosity functions, it's crucial to account for this completeness to understand the true population of sources. K-correction is another important concept, which adjusts observed data to account for redshift effects in the light from distant objects. Understanding both completeness and K-correction is essential for accurate astronomical analysis.
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Reading through various publications for Luminosity Functions and it mentions completeness a lot without ever explaining what it actually is. Could someone shed light on this please?

Thanks
 
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Also, what is 'K-correction'?

Cheers
 
jl294 said:
Reading through various publications for Luminosity Functions and it mentions completeness a lot without ever explaining what it actually is. Could someone shed light on this please?
'completeness' refers to how accurately collected data reflects the actual distribution of sources. Any astronomical survey will only detect the objects which are above the limiting brightness of the telescope/survey---everything dimmer, will not be seen. Therefore, anytime you're analyzing the statistics of your sample, you have to consider the 'completeness' of the survey---i.e. what types of sources (and how many) were detected, compared to what sources (and how many) weren't detected.
 

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