Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/51991

Title

Spectral energy distribution of radio sources in nearby clusters of galaxies: implications for Sunyaev-Zel'dovich effect surveys

Author(s)

Lin, Yen-Ting;  Partridge, Bruce;  Pober, J. C.;  El Bouchefry, Khadija;  Burke, Sarah;  Klein, Jonathan N.;  Coish, Joseph W.;  Huffenberger, Kevin M.

Abstract

To explore the high-frequency radio spectra of galaxies in clusters, we used NRAO's Very Large Array at four frequencies, 4.9-43 GHz, to observe 139 galaxies in low redshift (z < 0.25), X-ray detected, clusters. The clusters were selected from the survey conducted by Ledlow and Owen, who provided redshifts and 1.4 GHz flux densities for all the radio sources. We find that more than half of the observed sources have steep microwave spectra as generally expected (α < –0.5, in the convention S vprop να). However, 60%-70% of the unresolved or barely resolved sources have flat or inverted spectra. Most of these show an upward turn in flux at ν>22 GHz, implying a higher flux than would be expected from an extrapolation of the lower-frequency flux measurements. Our results quantify the need for careful source subtraction in increasingly sensitive measurements of the Sunyaev-Zel'dovich effect in clusters of galaxies (as currently being conducted by, for instance, the Atacama Cosmology Telescope and South Pole Telescope groups).

Publication type

Journal article

Source

Astrophysical Journal, Vol. 694, no. 2 (Apr 2009), pp. 992-1009

Publication year

2009

FOR Code(s)

0201 Astronomical and Space Sciences;  020103 Cosmology and Extragalactic Astronomy

Keyword(s)

Active galaxies;  Cluster galaxies;  Elliptical galaxies;  Lenticular;  Radio continuum galaxies

Publisher

Institute of Physics Publishing

ISSN

0004-637X

Publisher URL

http://dx.doi.org/10.1088/0004-637x/694/2/992

Copyright

Copyright © 2009 The American Astronomical Society. All rights reserved.

Peer reviewed