J/ApJ/704/1433 31GHz survey of low-frequency radio sources (Mason+, 2009)
A 31 GHz survey of low-frequency selected radio sources.
Mason B.S., Weintraub L., Sievers J., Bond J.R., Myers S.T., Pearson T.J.,
Readhead A.C.S., Shepherd M.C.
<Astrophys. J., 704, 1433-1447 (2009)>
=2009ApJ...704.1433M 2009ApJ...704.1433M
ADC_Keywords: Radio continuum ; Surveys ; Active gal. nuclei
Keywords: cosmic microwave background - cosmology: observations -
galaxies: active - radio continuum: galaxies
Abstract:
The 100m Robert C. Byrd Green Bank Telescope and the 40m Owens Valley
Radio Observatory telescope have been used to conduct a 31GHz survey
of 3165 known extragalactic radio sources over 143deg2 of the sky.
Target sources were selected from the NRAO VLA Sky Survey in fields
observed by the Cosmic Background Imager (CBI); most are extragalactic
active galactic nuclei (AGNs) with 1.4GHz flux densities of 3-10mJy.
The resulting 31GHz catalogs are presented in full online. Using a
maximum-likelihood analysis to obtain an unbiased estimate of the
distribution of the 1.4-31GHz spectral indices of these sources, we
find a mean 31-1.4GHz flux ratio of 0.110±0.003 corresponding to a
spectral index of α=-0.71±0.01
(Sν∝να); 9.0%±0.8% of sources have
α>-0.5 and 1.2%±0.2% have α>0. By combining this
spectral-index distribution with 1.4GHz source counts, we predict
31GHz source counts in the range 1mJy<S31<4mJy,
N(>S31)=(16.7±1.7)deg-2(S31/1mJy)-0.80±0.07.
Description:
In this paper, we present a detailed characterization of the impact
of the discrete source foreground on arcminute-scale 31GHz anisotropy
measurements based upon two observational campaigns. The first
campaign was carried out with the Owens Valley Radio Observatory
(OVRO) 40m telescope at 31GHz from 2000 September through 2002
December. The second campaign used the Robert C. Byrd Green Bank
Telescope (GBT) from 2006 February to May. A companion paper (Sievers
et al. 2009arXiv0901.4540S 2009arXiv0901.4540S) presents the five-year CBI total intensity
power spectrum incorporating the results of the point-source
measurements discussed here.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 81 1674 OVRO 40-m 31GHz survey results (2002 September
through 2002 December)
table3.dat 79 1490 GBT 100-m 31GHz survey results (2006 February
through 2006 May)
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See also:
VIII/85 : SPECFIND V2.0 Catalog of radio continuum spectra (Vollmer+ 2009)
VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)
J/A+A/501/801 : CBI sample at 4.85GHz and 10.45GHz (Angelakis+, 2009)
Byte-by-byte Description of file: table[23].dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name NVSS source name (HHMMSS+DDMM;
in Simbad)
13- 14 I2 h RAh Hour of Right Ascension (J2000)
16- 17 I2 min RAm Minute of Right Ascension (J2000)
19- 23 F5.2 s RAs Second of Right Ascension (J2000)
25 A1 --- DE- Sign of the Declination (J2000)
26- 27 I2 deg DEd Degree of Declination (J2000)
29- 30 I2 arcmin DEm Arcminute of Declination (J2000)
32- 35 F4.1 arcsec DEs Arcsecond of Declination (J2000)
37- 43 F7.2 mJy S31 The 31GHz flux density
45- 49 F5.2 mJy e_S31 Uncertainty in S31
51- 58 F8.2 mJy S1.4 The 1.4GHz NVSS integrated flux density
60- 65 F6.2 mJy e_S1.4 Uncertainty in S1.4
67- 71 F5.1 arcsec amaj ?=0 The 1.4GHz NVSS major axis
73- 77 F5.1 arcsec bmin ?=0 The 1.4GHz NVSS minor axis
79 A1 --- D [*] *: Indicates detection ≥ 4σ
81 A1 --- C [*] *: Indicates confusion-corrected flux
(see Appendix A)
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 25-Nov-2011