J/ApJ/694/992 SED of cluster radio galaxies (Lin+, 2009)
Spectral energy distribution of radio sources in nearby clusters of galaxies:
implications for Sunyaev-Zel'Dovich effect surveys.
Lin Y.-T., Partridge B., Pober J.C., El Bouchefry K., Burke S., Klein J.N.,
Coish J.W., Huffenberger K.M.
<Astrophys. J., 694, 992-1009 (2009)>
=2009ApJ...694..992L 2009ApJ...694..992L
ADC_Keywords: Clusters, galaxy ; Radio continuum ; Energy distributions
Keywords: galaxies: active - galaxies: clusters: general - galaxies: elliptical
and lenticular, cD - radio continuum: galaxies
Abstract:
To explore the high-frequency radio spectra of galaxies in clusters,
we used NRAO's Very Large Array at four frequencies, 4.9-43GHz, 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 (1997ApJS..108...41O 1997ApJS..108...41O), who provided redshifts and
1.4GHz 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{proto}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>22GHz, 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).
Description:
Measurements in all four spectral bands were made at default VLA
frequencies, centered at 43.3, 22.4, 8.5, and 4.9GHz (Q, K, X, and C
bands, respectively). The observations discussed here were made in
late 2005 October, with the VLA in a hybrid DnC configuration.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 138 192 Cluster radio sources
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See also:
J/MNRAS/376/1073 : Sunyaev-Zel'dovich effect in galaxy clusters (Zemcov+, 2007)
J/A+A/417/827 : Relativistic corrections to Sunyaev-Zeldovich effect (Itoh+,
2004)
J/A+A/402/37 : UV to radio SED of galaxies in Virgo cluster (Boselli+,
2003)
J/AJ/110/1959 : VLA survey of Abell clusters. V. (Ledlow+ 1995)
J/AJ/109/853 : VLA survey of Abell clusters. IV. (Ledlow+ 1995)
J/AJ/105/853 : Energy distributions of radio galaxies (Impey+ 1993)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- [LO95] Source name (1)
11- 13 F3.1 --- m_[LO95] ? Source component
15- 22 F8.4 deg RAdeg Right ascension in decimal degrees (J2000)
24- 31 F8.4 deg DEdeg Declination in decimal degrees (J2000)
33- 35 A3 --- Type Morphological indication (2)
37- 42 F6.4 --- z Redshift taken from Owen & Ledlow
(1997ApJS..108...41O 1997ApJS..108...41O)
44- 47 I4 mJy FL 1.4GHz flux (L-band) from Owen & Ledlow
(1997ApJS..108...41O 1997ApJS..108...41O)
49 A1 --- l_FC Limit flag on FC
50- 55 F6.2 mJy FC ? VLA C channel flux density (4.9GHz)
56 A1 --- u_FC [:] Uncertainty flag on FC
57- 61 F5.2 mJy e_FC ? FC uncertainty
63 A1 --- l_FX Limit flag on FX
64- 69 F6.2 mJy FX ? VLA X channel flux density (8.5GHz)
70 A1 --- u_FX [:] Uncertainty flag on FX
71- 75 F5.2 mJy e_FX ? FX uncertainty
77 A1 --- l_FK Limit flag on FK
78- 83 F6.2 mJy FK ? VLA K channel flux density (22.4GHz)
84 A1 --- u_FK [:] Uncertainty flag on FK
85- 89 F5.2 mJy e_FK ? FK uncertainty
91 A1 --- l_FQ Limit flag on FQ
92- 97 F6.2 mJy FQ ? VLA Q channel flux density (43.3GHz)
98 A1 --- u_FQ [:] Uncertainty flag on FQ
99-103 F5.2 mJy e_FQ ? FQ uncertainty
105 A1 --- l_aCX Limit flag on aCX
106-110 F5.2 --- aCX ? CX spectral index (αCX)
112 A1 --- l_aXK Limit flag on aXK
113-117 F5.2 --- aXK ? XK spectral index
119 A1 --- l_aKQ Limit flag on aKQ
120-124 F5.2 --- aKQ ? KQ spectral index (αKQ)
126-131 F6.2 mJy FCX ? Predicted flux at 90GHz based on the fluxes
at C and X bands and αCX
133-138 F6.2 mJy FKQ ? Predicted flux at 90GHz based on the fluxes
at K and Q bands and αKQ
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Note (1): Source name from Owen & Ledlow (1997ApJS..108...41O 1997ApJS..108...41O), which is
based on B1950 positions.
Note (2): Morphology of the sources as follows:
-1 = extended source;
C = core
P = point-like
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History:
* 23-Mar-2011: From electronic version of the journal
* 15-May-2012: Fixed the frequencies associated to the VLA fluxes in this
ReadMe file
(End) Emmanuelle Perret [CDS] 23-Mar-2011