A model for the cosmological evolution of low-frequency radio sources

Massardi, M.; Bonaldi, A.; Negrello, M.; Ricciardi, S.; Raccanelli, Alvise; Zotti, G. de

doi:10.1111/j.1365-2966.2010.16305.x

Cited by 98 publications

(171 citation statements)

References 102 publications

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“…On the other hand, its very simple assumptions on the extrapolation of source spectra at mm wavelengths as well as new data published in the last ten years make it currently not upof-date for more predictions, although it is still very useful for comparisons -even at ν ≥ 100 GHz -after a simple rescaling (see, e.g., Marriage et al 2011). A&A 533, A57 (2011) More recently, the De Zotti et al (2005) and Massardi et al (2010) new cosmological evolution models of radio sources have been able to give successful fits to the wealth of new available data on luminosity functions, multi-frequency source counts and also redshift distributions at frequencies > ∼ 5 GHz and < ∼ 5 GHz, respectively. These two models are based on an accurate determination of the epoch-dependent luminosity functions (l.f.) for different source populations, usually separated by the value of the spectral index, α, of the observed emission spectrum at low radio frequencies (1 < ∼ ν < ∼ 5 GHz) by adopting a simple powerlaw approximation, i.e., S (ν) ∝ ν α .…”

Section: Introductionmentioning

confidence: 99%

High-frequency predictions for number counts and spectral properties of extragalactic radio sources. New evidence of a break at mm wavelengths in spectra of bright blazar sources

Tucci

Toffolatti

Zotti

et al. 2011

A&A

103

201

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We present models to predict high-frequency counts of extragalactic radio sources using physically grounded recipes to describe the complex spectral behaviour of blazars that dominate the mm-wave counts at bright flux densities. We show that simple power-law spectra are ruled out by high-frequency (ν ≥ 100 GHz) data. These data also strongly constrain models featuring the spectral breaks predicted by classical physical models for the synchrotron emission produced in jets of blazars. A model dealing with blazars as a single population is, at best, only marginally consistent with data coming from current surveys at high radio frequencies. Our most successful model assumes different distributions of break frequencies, ν M , for BL Lacs and flat-spectrum radio quasars (FSRQs). The former objects have substantially higher values of ν M , implying that the synchrotron emission comes from more compact regions; therefore, a substantial increase of the BL Lac fraction at high radio frequencies and at bright flux densities is predicted. Remarkably, our best model is able to give a very good fit to all the observed data on number counts and on distributions of spectral indices of extragalactic radio sources at frequencies above 5 and up to 220 GHz. Predictions for the forthcoming sub-mm blazar counts from Planck, at the highest HFI frequencies, and from Herschel surveys are also presented.

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Section: Introductionmentioning

confidence: 99%

High-frequency predictions for number counts and spectral properties of extragalactic radio sources. New evidence of a break at mm wavelengths in spectra of bright blazar sources

Tucci

Toffolatti

Zotti

et al. 2011

A&A

103

201

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“…Based on these data, many works can be found in the literature where the authors aim at making, and subsequectly improving, the measurement of the ISW effect through correlations with tracer catalogues: 2MASS (an infrared catalogue out to low redshifts around 0.1, Afshordi et al 2004;Rassat et al 2007;Francis & Peacock 2010b;Dupé et al 2011), HEAO (an X-ray survey at low redshift, with the first positive claim of detection, Boughn & Crittenden 2004), Sloan Digital Sky Survey (SDSS, an optical survey at intermediate redshifts, Fosalba et al 2003;Scranton et al 2003;Fosalba & Gaztañaga 2004;Padmanabhan et al 2005;Cabré et al 2006;Giannantonio et al 2006;Granett et al 2009;Xia 2009;Bielby et al 2010;López-Corredoira et al 2010;Sawangwit et al 2010), the NRAO VLA Sky Survey (NVSS, a radio catalogue with high-redshift sources, Boughn & Crittenden 2005;Vielva et al 2006;Pietrobon et al 2006a;McEwen et al 2007;Raccanelli et al 2008;Hernández-Monteagudo 2010;Massardi et al 2010;Schiavon et al 2012), and combined measurements with multiple tracers (Nolta et al 2004;Ho et al 2008;Corasaniti et al 2005;Gaztañaga et al 2006;Giannantonio et al 2008Giannantonio et al , 2012. The significance of the ISW detections that can be found in the literature range between 0.9σ and 4.7σ.…”

Section: Introductionmentioning

confidence: 99%

Planck2013 results. XIX. The integrated Sachs-Wolfe effect

Ade¹,

Aghanim²,

Armitage-Caplan³

et al. 2014

A&A

135

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Based on cosmic microwave background (CMB) maps from the 2013 Planck Mission data release, this paper presents the detection of the integrated Sachs-Wolfe (ISW) effect, that is, the correlation between the CMB and large-scale evolving gravitational potentials. The significance of detection ranges from 2 to 4σ, depending on which method is used. We investigated three separate approaches, which essentially cover all previous studies, and also break new ground. (i) We correlated the CMB with the Planck reconstructed gravitational lensing potential (for the first time). This detection was made using the lensing-induced bispectrum between the low-and high-temperature anisotropies; the correlation between lensing and the ISW effect has a significance close to 2.5σ. (ii) We cross-correlated with tracers of large-scale structure, which yielded a significance of about 3σ, based on a combination of radio (NVSS) and optical (SDSS) data. (iii) We used aperture photometry on stacked CMB fields at the locations of known large-scale structures, which yielded and confirms a 4σ signal, over a broader spectral range, when using a previously explored catalogue, but shows strong discrepancies in amplitude and scale when compared with expectations. More recent catalogues give more moderate results that range from negligible to 2.5σ at most, but have a more consistent scale and amplitude, the latter being still slightly higher than what is expected from numerical simulations within ΛCMD. Where they can be compared, these measurements are compatible with previous work using data from WMAP, where these scales have been mapped to the limits of cosmic variance. Planck's broader frequency coverage allows for better foreground cleaning and confirms that the signal is achromatic, which makes it preferable for ISW detection. As a final step we used tracers of large-scale structure to filter the CMB data, from which we present maps of the ISW temperature perturbation. These results provide complementary and independent evidence for the existence of a dark energy component that governs the currently accelerated expansion of the Universe.

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“…The most recent estimates on source number counts up to ∼50−70 GHz, and the optical identifications of the corresponding bright point sources (see, e.g., Massardi et al 2008Massardi et al , 2010, show that these counts are dominated by radio sources whose average spectral index is "flat", i.e., α 0.0 (with the usual convention S ν ∝ ν α ). This result confirms that the underlying source population is essentially made of flat spectrum radio quasars (FSRQ) and BL Lac objects, collectively called blazars 3 , with minor contributions coming from other source populations (Toffolatti et al 1998;de Zotti et al 2005).…”

Section: Introductionmentioning

confidence: 99%

Planckearly results. XIII. Statistical properties of extragalactic radio sources in thePlanckEarly Release Compact Source Catalogue

Ade¹,

Aghanim²,

Argüeso³

et al. 2011

A&A

105

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The data reported in Planck's Early Release Compact Source Catalogue (ERCSC) are exploited to measure the number counts (dN/dS ) of extragalactic radio sources at 30, 44, 70, 100, 143 and 217 GHz. Due to the full-sky nature of the catalogue, this measurement extends to the rarest and brightest sources in the sky. At lower frequencies (30, 44, and 70 GHz) our counts are in very good agreement with estimates based on WMAP data, being somewhat deeper at 30 and 70 GHz, and somewhat shallower at 44 GHz. Planck's source counts at 143 and 217 GHz join smoothly with the fainter ones provided by the SPT and ACT surveys over small fractions of the sky. An analysis of source spectra, exploiting Planck's uniquely broad spectral coverage, finds clear evidence of a steepening of the mean spectral index above about 70 GHz. This implies that, at these frequencies, the contamination of the CMB power spectrum by radio sources below the detection limit is significantly lower than previously estimated.

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A model for the cosmological evolution of low-frequency radio sources

Cited by 98 publications

References 102 publications

High-frequency predictions for number counts and spectral properties of extragalactic radio sources. New evidence of a break at mm wavelengths in spectra of bright blazar sources

High-frequency predictions for number counts and spectral properties of extragalactic radio sources. New evidence of a break at mm wavelengths in spectra of bright blazar sources

Planck2013 results. XIX. The integrated Sachs-Wolfe effect

Planckearly results. XIII. Statistical properties of extragalactic radio sources in thePlanckEarly Release Compact Source Catalogue

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