The ATLAS 5.5 GHz Survey of the Extended Chandra Deep Field South: The Second Data Release

Abstract

We present a new image of the 5.5 GHz radio emission from the extended Chandra Deep Field South. Deep radio observations at 5.5 GHz were obtained in 2010 and presented in the first data release. A further 76 hours of integration has since been obtained, nearly doubling the integration time. This paper presents a new analysis of all the data. The new image reaches 8.6 microJy rms, an improvement of about 40% in sensitivity. We present a new catalogue of 5.5 GHz sources, identifying 212 source components, roughly 50% more than were detected in the first data release. Source counts derived from this sample are consistent with those reported in the literature for S_{5.5GHz} > 0.1 mJy but significantly lower than published values in the lowest flux density bins (S_{5.5GHz} < 0.1 mJy), where we have more detected sources and improved statistical reliability. The 5.5 GHz radio sources were matched to 1.4 GHz sources in the literature and we find a mean spectral index of -0.35 +- 0.10 for S_{5.5GHz} > 0.5 mJy, consistent with the flattening of the spectral index observed in 5 GHz sub-mJy samples. The median spectral index of the whole sample is α_{med} = -0.58, indicating that these observations may be starting to probe the star forming population. However, even at the faintest levels (0.05 < S_{5.5GHz} < 0.1 mJy), 39% of the 5.5 GHz sources have flat or inverted radio spectra. Four flux density measurements from our data, across the full 4.5 to 6.5 GHz bandwidth, are combined with those from literature and we find 10% of sources (S_{5.5GHz} >~ 0.1 mJy) show significant curvature in their radio spectral energy distribution spanning 1.4 to 9 GHz.

arXiv commentAccepted for publication in MNRAS. 22 pages, including 12 figures and catalogue. Draws upon and extends the work of arXiv:1208.6306 with additional data

References in corpus (46)

• The Demography of Massive Dark Objects in Galaxy Centres
• On the normalisation of the cosmic star formation history
• New Insight on Galaxy Formation and Evolution from Keck Spectroscopy of the Hawaii Deep Fields
• Luminosity-dependent evolution of soft X-ray selected AGN: New Chandra and XMM-Newton surveys
• EMU: Evolutionary Map of the Universe
• The evolution of the hard X-ray luminosity function of AGN
• Cosmic Star Formation History and its Dependence on Galaxy Stellar Mass
• The Australia Telescope Compact Array Broadband Backend (CABB)
• A semi-empirical simulation of the extragalactic radio continuum sky for next generation radio telescopes
• The VLA-COSMOS Survey: II. Source Catalog of the Large Project
• Post-correlation radio frequency interference classification methods
• Compact continuum source-finding for next generation radio surveys
• The VLA-COSMOS Survey. IV. Deep Data and Joint Catalog
• Resolving the Radio Source Background: Deeper Understanding Through Confusion
• The Star Formation History of the Universe as Revealed by Deep Radio Observations
• The Far-Infrared--Radio Correlation at High Redshifts: Physical Considerations and Prospects for the Square Kilometer Array
• Controlling the False Discovery Rate in Astrophysical Data Analysis
• The sub-mJy radio sky in the Extended Chandra Deep Field South: source population
• A new method to separate star forming from AGN galaxies at intermediate redshift: The submillijansky radio population in the VLA-COSMOS survey
• A new source detection algorithm using FDR
• High Resolution Studies of Radio Sources in the Hubble Deep and Flanking Fields
• The VLA Survey of the Chandra Deep Field South. V. Evolution and Luminosity Functions of sub-mJy radio sources and the issue of radio emission in radio-quiet AGN
• Deep multi-frequency radio imaging in the Lockman Hole using the GMRT and VLA: I. The nature of the sub-mJy radio population
• A deep VLA survey at 6 cm in the Lockman Hole
• BLOBCAT: Software to Catalogue Flood-Filled Blobs in Radio Images of Total Intensity and Linear Polarization
• The VLA 1.4GHz Survey of the Extended Chandra Deep Field South: Second Data Release
• Duchamp: a 3D source finder for spectral-line data
• VAST: An ASKAP Survey for Variables and Slow Transients
• The VLA Survey of the Chandra Deep Field South: I. Overview of the Radio Data
• Radio Observations of the Hubble Deep Field South Region II: The 1.4 GHz Catalogue and Source Counts
• A search for distant radio galaxies from SUMSS and NVSS: III. radio spectral energy distributions and the z-alpha correlation
• The VLA Survey of the Chandra Deep Field South. IV. Source Population
• The ATESP radio survey III. Source counts
• The accretion history of the Universe with the SKA
• The ATESP 5 GHz radio survey I. Source counts and spectral index properties of the faint radio population
• An infrared-radio simulation of the extragalactic sky: from the Square Kilometer Array to Herschel
• Sample variance, source clustering and their influence on the counts of faint radio sources
• Spectral index properties of milliJansky radio sources
• Relation Between Stellar Mass and Star Formation Activity in Galaxies
• An unbiased sample of bright southern Compact Steep Spectrum and Gigahertz Peaked Spectrum Sources
• The faint source population at 15.7 GHz - I. The radio properties
• A search for variable and transient radio sources in the extended Chandra Deep Field South at 5.5 GHz
• The ATLAS 5.5 GHz survey of the Extended Chandra Deep Field South: Catalogue, Source Counts and Spectral Indices
• The completeness and reliability of threshold and false-discovery-rate source extraction algorithms for compact continuum sources
• Deep 20-GHz survey of the Chandra Deep Field South and SDSS Stripe 82: source catalogue and spectral properties
• Radio Observations of the Hubble Deep Field South Region IV: Optical Properties of the Faint Radio Population

Cited by in corpus (18)

• Nowhere to Hide: Radio-faint AGN in the GOODS-N field. I. Initial catalogue and radio properties
• A deep / wide 1-2 GHz snapshot survey of SDSS Stripe 82 using the Karl G. Jansky Very Large Array in a compact hybrid configuration
• Completing the Census of AGN in GOODS-S/HUDF: New Ultra-Deep Radio Imaging and Predictions for JWST
• VLA imaging of the XMM-LSS / VIDEO deep field at 1-2 GHz
• Nature of Faint Radio Sources in GOODS-North and GOODS-South Fields - I. Spectral Index and Radio-FIR Correlation
• Remnant Radio Galaxies Discovered in a Multi-frequency Survey
• The XXL Survey XVIII. ATCA 2.1 GHz radio source catalogue and source counts for the XXL-South field
• The AT-LESS CO(1-0) survey of submillimetre galaxies in the Extended Chandra Deep Field South: First results on cold molecular gas in galaxies at z ~ 2
• The XMM deep survey in the CDFS XI. X-ray properties of 185 bright sources
• The MAVERIC Survey: Radio catalogs and source counts from deep Very Large Array imaging of 25 Galactic globular clusters
• High-resolution Observations of Low-luminosity Gigahertz-Peaked Spectrum and Compact Steep Spectrum Sources
• The cosmic radio background from 150 MHz--8.4 GHz, and its division into AGN and star-forming galaxy flux
• The VLA Frontier Fields Survey: Deep, High-resolution Radio Imaging of the MACS Lensing Clusters at 3 and 6 GHz
• PKS 2250$-$351: A Giant Radio Galaxy in Abell 3936
• Selecting and Modelling Remnant AGNs with Limited Spectral Coverage
• Sensitive Radio Survey of Obscured Quasar Candidates
• The ATLAS 9.0 GHz Survey of the Extended Chandra Deep Field South: The Faint 9.0 GHz Radio Population
• Properties of Polarized Radio Sources in the Wide Chandra Deep Field South from 2 to 4GHz