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Author
dc.contributor.author
Dobos, L 
Author
dc.contributor.author
Csabai, I 
Availability Date
dc.date.accessioned
2020-08-11T09:38:14Z
Availability Date
dc.date.available
2020-08-11T09:38:14Z
Release
dc.date.issued
2011
uri
dc.identifier.uri
http://hdl.handle.net/10831/48152
Abstract
dc.description.abstract
We apply order statistics (OS) to the bright end (M(r) < -22) of the luminosity distribution of early-type galaxies spectroscopically identified in the SDSS DR7 catalogue. We show that an overall normalized luminosity function can be derived from the data that describes the distribution of red elliptical galaxies sufficiently for the purposes of OS in a broad redshift range of 0.1 <= z <= 0.5. We calculate the typical OS quantities of this distribution numerically, measuring the expectation value and variance of the kth most luminous galaxy in a sample with cardinality N over a large ensemble of such samples. From these statistical quantities, we explain why and in what limit the kth most luminous galaxies can be used as standard candles for cosmological studies. As a sample application of OS, we show that galaxy counts in different redshift ranges can be easily estimated if the absolute magnitude of the few most luminous galaxies and the overall shape of the luminosity function is known (and does not change significantly with z). First, we demonstrate that the absolutemagnitude of the kth most luminous early-type galaxies can be estimated from galaxy number counts in the investigated redshift range. By reversing the method, galaxy counts can also be very easily calculated, for example, in redshift ranges where spectroscopic data are available only for the brightest sources. Since our sample contains all bright galaxies including the brightest cluster galaxies (BCGs), based on OS we argue that BCGs can be considered as statistical extremes of a well-established Schechter luminosity distribution when galaxies are binned by redshift and not cluster-by-cluster. We presume that the reason behind this might be that luminous red ellipticals in galaxy clusters are not random samples of an overall luminosity distribution but biased by the fact that they are in a cluster containing the BCG. We show that a simple statistical toy model can reproduce the well-known magnitude gap between the BCG and the second brightest galaxy of the clusters.
Language
dc.language
Angol
Title
dc.title
Order statistics of the early-type galaxy luminosity function
Type
dc.type
folyóiratcikk
Date Change
dc.date.updated
2020-05-22T11:13:40Z
Scope
dc.format.page
1862-1874
Doi ID
dc.identifier.doi
10.1111/j.1365-2966.2011.18494.x
Wos ID
dc.identifier.wos
000292977600006
ID Scopus
dc.identifier.scopus
79959386945
MTMT ID
dc.identifier.mtmt
1690819
Issue Number
dc.identifier.issue
3
abbreviated journal
dc.identifier.jabbrev
MON NOT R ASTRON SOC
Journal
dc.identifier.jtitle
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
Volume Number
dc.identifier.volume
414
Release Date
dc.description.issuedate
2011
department of Author
dc.contributor.institution
Fizika Doktori Iskola
department of Author
dc.contributor.institution
Komplex Rendszerek Fizikája Tanszék
Author institution
dc.contributor.department
Komplex Rendszerek Fizikája Tanszék
Author institution
dc.contributor.department
Komplex Rendszerek Fizikája Tanszék


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Order statistics of the early-type galaxy luminosity function
 

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