Deep radio continuum studies with the SKA: evolution of radio AGN populations

Jackson, C. A.

doi:10.1016/j.newar.2004.09.023

Cited by 22 publications

(22 citation statements)

References 23 publications

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“…The relative numbers of extended AGNs found in the SSA 13 field are somewhat sparse, as expected from other surveys at somewhat higher flux densities (Jackson 2004). At about 1 mJy, the density of FR I sources is about 4 times that of FR II sources.…”

supporting

confidence: 75%

The Radio/Optical Catalog of the SSA 13 Field

Fomalont

Kellermann

Cowie

et al. 2006

ASTROPHYS J SUPPL S

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We present a 1.4 GHz catalog of 810 radio sources (560 sources in the complete sample) found in the SSA 13 field (R.A. = 13 h 12 m , decl. = 42 38 0 ). The 1.4 GHz radio image was obtained from a 91 hr VLA integration with an rms noise level of 4.82 Jy beam À1 at the field center. Optical images in the R band (6300 8) and z band (9200 8) with 3 detection magnitudes of 26.1 and 24.9, respectively, were obtained from three observing nights on the 8 m Subaru Telescope. We find that 88% AE 2% of the radio sources are identified with an optical counterpart. There is significantly more reddening for the optical counterparts that are fainter than 24 mag, probably caused by the somewhat larger redshifts of these faint galaxies. The radio and optical parameters are tabulated, and source morphologies are displayed by radio contours overlaid on optical false-color images. The brightness distributions show a wealth of complexity and are classified into a small number of categories. About one-third of the radio sources are larger than 1B2, and their orientation is often similar to that of the associated galaxy or binary galaxy system. Radio emission is sometimes located outside of the nuclear regions of the galaxy. The density of sources in the SSA 13 field above 75 Jy is 0.40 arcmin À2, with a slope of À2.43 in the differential counts. This source density is somewhat higher than that in the Hubble Deep Field North. The radio spectral index may steepen for sources below 75 Jy and is consistent with the difference in the slope of the source counts observed between 1.4 and 8.4 GHz. We estimate that at most 40% of the microjansky radio sources are dominated by AGN processes, while the remainder are mostly the consequence of star formation and associated supernova activity.

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supporting

confidence: 75%

The Radio/Optical Catalog of the SSA 13 Field

Fomalont

Kellermann

Cowie

et al. 2006

ASTROPHYS J SUPPL S

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“…Since future radio detectors such as the square kilometer array (SKA) [60] can reach point flux sensitivities of ∼ 1µJy, we show the power spectra of the background remaining after a corresponding luminosity cut in Fig. 6.…”

Section: Anisotropymentioning

confidence: 99%

Dark matter signatures in the anisotropic radio sky

Zhang

Sigl

2008

J. Cosmol. Astropart. Phys.

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Abstract. We calculate intensity and angular power spectrum of the cosmological background of synchrotron emission from cold dark matter annihilations into electron positron pairs. We compare this background with intensity and anisotropy of astrophysical and cosmological radio backgrounds, such as from normal galaxies, radiogalaxies, galaxy cluster accretion shocks, the cosmic microwave background and with Galactic foregrounds. Under modest assumptions for the dark matter clustering we find that around 2 GHz average intensity and fluctuations of the radio background at sub-degree scales allows to probe dark matter masses > ∼ 100 GeV and annihilation cross sections not far from the natural values σv ∼ 3 × 10 −26 cm 3 s −1 required to reproduce the correct relic density of thermal dark matter. The angular power spectrum of the signal from dark matter annihilation tends to be flatter than that from astrophysical radio backgrounds. Furthermore, radio source counts have comparable constraining power. Such signatures are interesting especially for future radio detectors such as SKA.PACS numbers: 95.35.+d, 95.85.Bh, 98.70.Vc

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“…Confusion by adjacent sources.-Long integrations at low frequencies (20 and 13 cm) are likely to reach the confusion limit at which each source of interest is confused by an adjacent background source. Assuming the log N /log S function taken from Jackson (2004), the confusion level for a 6 00 beam at 20 cm is 0.05 Jy beam À1 (i.e., on average, 1 background 0.05 Jy source will fall within each beam). Thus, this does not currently present a limit to synthesis observations for any realistic amount of observing time.…”

Section: The Limiting Sensitivity Of Synthesis Observationsmentioning

confidence: 99%

“…For the 6 km configuration of ATCA, using the same source statistics measured by Jackson (2004) and assuming a spectral index of À0.7, this gives a practical sensitivity limit of 21, 6, 0.7, and 0.03 Jy at 20, 13, 6, and 3 cm, respectively. The 20 cm observations described here already approach this limit.…”

Section: The Limiting Sensitivity Of Synthesis Observationsmentioning

confidence: 99%

Radio Observations of the Hubble Deep Field-South Region. I. Survey Description and Initial Results

et al. 2005

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This paper is the first of a series describing the results of the Australia Telescope Hubble Deep Field-South radio survey. The survey was conducted at four wavelengths, 20, 11, 6, and 3 cm, over a 4 year period and achieves an rms sensitivity of about 10 Jy at each wavelength. We describe the observations and data reduction processes and present data on radio sources close to the center of the Hubble Deep Field-South. We discuss in detail the properties of a subset of these sources. The sources include both starburst galaxies and galaxies powered by an active galactic nucleus and range in redshift from 0.1 to 2.2. Some of them are characterized by unusually high radio-to-optical luminosities, presumably caused by dust extinction.

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Deep radio continuum studies with the SKA: evolution of radio AGN populations

Cited by 22 publications

References 23 publications

The Radio/Optical Catalog of the SSA 13 Field

The Radio/Optical Catalog of the SSA 13 Field

Dark matter signatures in the anisotropic radio sky

Radio Observations of the Hubble Deep Field-South Region. I. Survey Description and Initial Results

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