scholarly journals Evidence for Steep Luminosity Functions in Clusters of Galaxies

1995 ◽  
Vol 450 ◽  
pp. 534 ◽  
Author(s):  
Roberto de Propris ◽  
Christopher J. Pritchet ◽  
William E. Harris ◽  
Robert D. McClure
Keyword(s):  
Clusters Of Galaxies ◽  
Luminosity Functions

Extragalactic X-ray sources and the diffuse X-ray background

1979 ◽  
Vol 366 (1726) ◽  
pp. 391-402 ◽  
Keyword(s):  
Spatial Distribution ◽  
Euclidean Space ◽  
Active Galaxies ◽  
Clusters Of Galaxies ◽  
Optical Identification ◽  
X Ray ◽  
Luminosity Functions ◽  
Sky Survey ◽  
Order Of Magnitude ◽  
X Ray Background

Results from the Ariel 5 sky survey instrument relating to the properties and the spatial distribution of extragalactic X-ray sources are discussed. The lg N -lg S relation for sources in the 2A catalogue is consistent with a uniform distribution of sources in Euclidean space. In addition, measure­ments of fluctuations in the X-ray background suggest that the Euclidean form of the source counts can be extrapolated to flux levels at least an order of magnitude fainter than the 2A catalogue limit. Information is also available from the optical identification of 2A sources which, through redshift measurements, enables the X-ray luminosity functions of the two main classes of source, namely clusters of galaxies and active galaxies, to be determined. The luminosity functions can be used to calculate the contribution of clusters of galaxies and active galaxies to the diffuse X-ray background in the 2-10 keV range. It is found that cosmological evolution of one or both populations is required to account for the diffuse X-ray background entirely in terms of the integrated emission from these sources.

X-ray luminosity functions of clusters of galaxies

1991 ◽  
Vol 366 ◽  
pp. L61 ◽  
Author(s):  
A. Cavaliere ◽  
R. Burg ◽  
R. Giacconi
Keyword(s):  
Clusters Of Galaxies ◽  
X Ray ◽  
Luminosity Functions

The Hα Luminosity Functions of Nearby Clusters of Galaxies

2002 ◽  
pp. 419-420
Author(s):  
J. Iglesias-Páramo ◽  
A. Boselli ◽  
J. M. Vílchez ◽  
L. Cortese ◽  
G. Gavazzi
Keyword(s):  
Clusters Of Galaxies ◽  
Luminosity Functions

Differences in the Luminosity Functions of Faint Early-Type and Faint Late-Type Galaxies in Four Nearby Clusters of Galaxies

1995 ◽  
Vol 452 (2) ◽  
Author(s):  
Nobunari Kashikawa ◽  
Kazuhiro Shimasaku ◽  
Masafumi Yagi ◽  
Naoki Yasuda ◽  
Mamoru Doi ◽  
...  
Keyword(s):  
Clusters Of Galaxies ◽  
Early Type ◽  
Late Type ◽  
Luminosity Functions

Luminosity Functions of 10 Nearby Clusters of Galaxies. II. Analysis of the Luminosity Function

2002 ◽  
Vol 123 (1) ◽  
pp. 87-99 ◽  
Author(s):  
M. Yagi ◽  
N. Kashikawa ◽  
M. Sekiguchi ◽  
M. Doi ◽  
N. Yasuda ◽  
...  
Keyword(s):  
Luminosity Function ◽  
Clusters Of Galaxies ◽  
Luminosity Functions

Luminosity Functions of 10 Nearby Clusters of Galaxies. I. Data

2002 ◽  
Vol 123 (1) ◽  
pp. 66-86 ◽  
Author(s):  
M. Yagi ◽  
N. Kashikawa ◽  
M. Sekiguchi ◽  
M. Doi ◽  
N. Yasuda ◽  
...  
Keyword(s):  
Clusters Of Galaxies ◽  
Luminosity Functions

USING WEAK-LENSING DILUTION TO MEASURE LIGHT PROPERTIES OF A1689

2008 ◽  
Vol 23 (17n20) ◽  
pp. 1521-1528 ◽  
Author(s):  
ELINOR MEDEZINSKI ◽  
TOM BROADHURST ◽  
KEIICHI UMETSU ◽  
DAN COE
Keyword(s):  
Luminosity Function ◽  
Dilution Effect ◽  
Weak Lensing ◽  
Large Radius ◽  
Clusters Of Galaxies ◽  
New Approach ◽  
Luminosity Functions ◽  
Galaxy Populations ◽  
Constant Slope ◽  
Massive Cluster

Weak-lensing induced by clusters of galaxies can probe the total mass distribution out to the virial radius of the cluster, regardless of the nature of the mass or its dynamical state. To make a robust analysis, the cluster and background galaxy populations need to be separated. The E/S0 sequence of a cluster defines a boundary redward of which a reliable weak-lensing signal can be obtained from background galaxies, uncontaminated by the cluster. Below this limit, the signal is diluted by the proportion of unlensed cluster members. Employing deep Subaru and HST/ACS images of the massive cluster A1689, we use this dilution effect to carefully separate between the cluster members and the background, and thus derive the cluster light profile and luminosity functions to large radius. The light profile of A1689 is found to decline steadily to the limit of the data, r < 2 h−1 Mpc , with a constant slope, d log (L)/d log (r) = −1.12 ± 0.06. We derive a cluster luminosity function with a flat faint-end slope of α = −1.05 ± 0.07, nearly independent of radius and with no faint upturn to Mi′ < −12. The major advantage of this new approach is that no subtraction of far-field background counts is required.

scholarly journals The Westerbork Survey of Rich Clusters of Galaxies

1980 ◽  
Vol 5 ◽  
pp. 715-721 ◽  
Author(s):  
Edwin A. Valentijn
Keyword(s):  
Luminosity Function ◽  
Point Of View ◽  
Clusters Of Galaxies ◽  
Radio Luminosity ◽  
General Reference ◽  
Statistical Point ◽  
Cluster Galaxies ◽  
Luminosity Functions ◽  
The Galaxy ◽  
Radio Luminosity Function

In the Westerbork Survey of Rich Clusters of galaxies (WSRC), seven nearby and rich clusters of galaxies have been observed with the Westerbork Synthesis Radio Telescope. The results obtained at different frequencies are published in several papers of a series, and Table 1 serves as a general reference to these publications. In these papers, both discussions on individual radio sources and the presentation of cluster radio luminosity functions (RLF) are given. Here we summarize some of the results of the WSRC which, from a statistical point of view, impose some constraints on the rate of the radio activity of galaxies and on the influence of the galaxy environments on their activity. The rate of radio activity of a sample of galaxies in a cluster can be described by the integral RLF of the cluster, which represents the fraction of galaxies that emit in the radio domain above a certain power. When it is presented as a function of the optical luminosities of the cluster galaxies, it is called the bivariate radio luminosity function (BRLF). The BRLFs are most suitable for representing in an unbiased way the rate of activity of a sample of galaxies, since they are presented in absolute parameters and are normalized to the optical luminosity function (or distribution) of the galaxy samples. This is important since, both inside and outside clusters, it has been shown that the RLF depends strongly on the optical luminosities.

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