A sample of 669 ultra steep spectrum radio sources to find high redshift radio galaxies
نویسندگان
چکیده
منابع مشابه
A Sample of 669 Ultra Steep Spectrum Radio Sources to Find High Redshift Radio Galaxies ⋆
Since radio sources with Ultra Steep Spectra (USS; α ∼ < −1.30;S ∝ ν) are efficient tracers of high redshift radio galaxies (HzRGs), we have defined three samples of such USS sources using the recently completed WENSS, TEXAS, MRC, NVSS and PMN radiosurveys. Our combined sample contains 669 sources with S1400 > 10 mJy and covers virtually the entire sky outside the Galactic plane (|b| > 15). For...
متن کاملMultiwavelength characterization of faint ultra steep spectrum radio sources: A search for high-redshift radio galaxies ⋆
Context. Ultra steep spectrum (USS) radio sources are one of the efficient tracers of powerful high-z radio galaxies (HzRGs). In contrast to searches for powerful HzRGs from radio surveys of moderate depths, fainter USS samples derived from deeper radio surveys can be useful in finding HzRGs at even higher redshifts and in unveiling a population of obscured weaker radio-loud AGN at moderate red...
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We use the 6C** sample to investigate the co-moving space density of powerful, steepspectrum radio sources. This sample, consisting of 68 objects, has virtually complete K-band photometry and spectroscopic redshifts for 32 per cent of the sources. In order to find its complete redshift distribution, we develop a method of redshift estimation based on the K − z diagram of the 3CRR, 6CE, 6C* and ...
متن کاملSpectroscopy of Ultra Steep Spectrum Radio Sources
We present optical spectroscopy of 62 objects selected from several samples of ultra steep spectrum (USS) radio sources. 46 of these are from our primary catalog, consisting of 669 sources with radio spectral indices α < −1.30 (Sν ∝ ν); this first spectroscopic sub-sample was selected on the basis of their faint optical and near-IR identifications. Most are identified as narrow-lined radio gala...
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We use three samples (3CRR, 6CE and 6C*) selected at low radio frequency to constrain the cosmic evolution in the radio luminosity function (RLF) for the ‘most luminous’ steep-spectrum radio sources. Although intrinsically rare, such sources give the largest possible baseline in redshift for the complete flux-density-limited samples currently available. Using parametric models to describe the R...
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ژورنال
عنوان ژورنال: Astronomy and Astrophysics Supplement Series
سال: 2000
ISSN: 0365-0138,1286-4846
DOI: 10.1051/aas:2000181