Issue |
A&A
Volume 396, Number 1, December II 2002
|
|
---|---|---|
Page(s) | 83 - 89 | |
Section | Cosmology (including clusters of galaxies) | |
DOI | https://doi.org/10.1051/0004-6361:20021382 | |
Published online | 22 November 2002 |
The radio luminosity function of cluster radio halos
1
Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str.1, Postfach 1317, 85741 Garching, Germany
2
Sterrewacht, Oort Gebouw, PO Box 9513, 2300 RA Leiden, The Netherlands
Corresponding author: T. A. Enßlin, ensslin@mpa-garching.mpg.de
Received:
19
April
2002
Accepted:
11
September
2002
A significant fraction of galaxy clusters exhibits
cluster-wide radio halos. We give a simple prediction of the local and
higher redshift radio halo luminosity function (RHLF) on the basis of
(i) an observed and a theoretical X-ray cluster luminosity function
(XCLF) (ii) the observed radio–X-ray luminosity correlation (RXLC) of
galaxy clusters with radio halos (iii) an assumed fraction of galaxy clusters to have radio halos as supported
by observations. We then find 300–700 radio halos with
mJy, and 105–106 radio halos with
Jy should be visible on the sky. 14% of the
mJy and 56% of the
Jy halos are located
at
.
Subsequently, we give more realistic predictions taking into account
(iv) a refined estimate of the radio halo fraction as a function of
redshift and cluster mass, and (v) a decrease in intrinsic radio halo
luminosity with redshift due to increased inverse Compton electron
energy losses on the Cosmic Microwave Background (CMB). We find that
this reduces the radio halo counts from the simple prediction by only
30 % totally, but the high redshift (
) counts are more
strongly reduced by 50–70%.
These calculations show that the new generation of sensitive radio
telescopes, including LOFAR, ATA, EVLA, SKA and the already-operating
GMRT should be able to detect large numbers of radio halos and will
provide unique information for studies of galaxy cluster merger rates
and associated non-thermal processes.
Key words: X-rays: galaxies: clusters / radiation mechanism: non-thermal / radio continuum: general / galaxies: intergalactic medium / galaxies: cluster: general
© ESO, 2002
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.