Issue |
A&A
Volume 446, Number 1, January IV 2006
|
|
---|---|---|
Page(s) | 97 - 111 | |
Section | Extragalactic astronomy | |
DOI | https://doi.org/10.1051/0004-6361:20053767 | |
Published online | 09 January 2006 |
The radio luminosity function of the NEP distant cluster radio galaxies
1
Dipartimento di Astronomia, Università di Bologna, via Ranzani 1, 40127 Bologna, Italy e-mail: m.branchesi@ira.inaf.it
2
Istituto di Radioastronomia, INAF-CNR, via Gobetti 101, 40129 Bologna, Italy e-mail: gioia@ira.inaf.it
3
Dipartimento di Fisica, Università di Bologna, via Irnerio 46, 40126 Bologna, Italy e-mail: [rfanti;cfanti]@ira.inaf.it
4
National Radio Astronomy Observatory, PO Box O, Socorro, NM 87801, USA e-mail: rperley@nrao.edu
Received:
5
July
2005
Accepted:
8
September
2005
A complete sample of 18 X-ray selected clusters of galaxies
belonging to the ROSAT North Ecliptic Pole (NEP) survey has been
observed with the Very Large Array at 1.4 GHz in B configuration.
These are the most distant clusters in the X-ray survey with redshift in the
range . Seventy-nine radio sources are detected within
half an Abell radius with an observed peak brightness
0.17 mJy beam-1,
except for three sources, belonging to the same cluster,
which have a higher peak brightness limit of 0.26 mJy beam-1. The NEP
field source counts are in good agreement with the source
counts of a comparison survey, the VLA-VIRMOS deep field survey, indicating
that the NEP sample is statistically complete. Thirty-two out of the 79 sources are within
0.2 Abell radii, twenty-two of them are considered cluster
members based on spectroscopic redshifts or their optical magnitude and
morphological classification. The cluster radio galaxies are used to
construct the Radio Luminosity Function (RLF) of distant X-ray selected
clusters. A comparison with two nearby cluster RLFs shows that the NEP RLF
lies above the local ones, has a steeper slope at low radio powers
(≤1024 W Hz-1) and shows no evidence for a break at
W Hz-1 which is observed in the nearby cluster RLFs.
We discuss briefly the origin and possible explanations of the differences
observed in the radio properties of nearby and distant clusters of galaxies.
The main result of this study is that the RLF of the distant X-ray clusters
is very different from that of the local rich Abell clusters.
Key words: galaxies: clusters: general / galaxies: high-redshift / galaxies: evolution / radio continuum: galaxies / cosmology: observations / X-rays: galaxies: clusters
© ESO, 2006
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.