The e-MERLIN Galaxy Evolution Survey (e-MERGE): Overview and Survey Description

Abstract

We present an overview and description of the eMERLIN Galaxy Evolution survey (eMERGE) Data Release 1 (DR1), a large program of high-resolution 1.5 GHz radio observations of the GOODS-N field comprising $\sim 140$ hours of observations with eMERLIN and $\sim 40$ hours with the Very Large Array (VLA). We combine the long baselines of eMERLIN (providing high angular resolution) with the relatively closely-packed antennas of the VLA (providing excellent surface brightness sensitivity) to produce a deep 1.5 GHz radio survey with the sensitivity ($\sim 1.5\mu$Jy beam${}^{-1}$), angular resolution ($0.2"$--$0.7"$) and field-of-view ($\sim 15^{\prime }\times 15^{\prime }$) to detect and spatially resolve star-forming galaxies and AGN at $z\gtrsim 1$. The goal of eMERGE is to provide new constraints on the deep, sub-arcsecond radio sky which will be surveyed by SKA1-mid. In this initial publication, we discuss our data analysis techniques, including steps taken to model in-beam source variability over a $\sim 20$ year baseline and the development of new point spread function/primary beam models to seamlessly merge eMERLIN and VLA data in the $uv$ plane. We present early science results, including measurements of the luminosities and/or linear sizes of $\sim 500$ galaxes selected at 1.5 GHz. In combination with deep Hubble Space Telescope observations, we measure a mean radio-to-optical size ratio of $r_{\mathrm{eMERGE}}/r_{\mathrm{HST}}\sim 1.02\pm 0.03$, suggesting that in most high-redshift galaxies, the $\sim$GHz continuum emission traces the stellar light seen in optical imaging. This is the first in a series of papers which will explore the $\sim$kpc-scale radio properties of star-forming galaxies and AGN in the GOODS-N field observed by eMERGE DR1.

21 pages, 12 colour figures, 3 tables -- accepted for publication in MNRAS

References in corpus (27)

• The EAGLE project: Simulating the evolution and assembly of galaxies and their environments
• The Cosmic Evolution Survey (COSMOS) -- Overview
• 3D-HST+CANDELS: The Evolution of the Galaxy Size-Mass Distribution since $z=3$
• 3D-HST WFC3-selected Photometric Catalogs in the Five CANDELS/3D-HST Fields: Photometry, Photometric Redshifts and Stellar Masses
• WSClean: an implementation of a fast, generic wide-field imager for radio astronomy
• Multi-Scale CLEAN deconvolution of radio synthesis images
• An optimized algorithm for multi-scale wideband deconvolution of radio astronomical images
• AGN-controlled cooling in elliptical galaxies
• The Star Formation History of the Universe as Revealed by Deep Radio Observations
• The far-infrared/radio correlation and radio spectral index of galaxies in the SFR-M* plane up to z 2
• Prevalence of radio jets associated with galactic outflows and feedback from quasars
• The kiloparsec-scale star formation law at redshift 4: wide-spread, highly efficient star formation in the dust-obscured starburst galaxy GN20
• VLA and ALMA Imaging of Intense, Galaxy-Wide Star Formation in z ~ 2 Galaxies
• The VLA-COSMOS Survey: III. Further Catalog Analysis and the Radio Source Counts
• An ALMA survey of the SCUBA-2 Cosmology Legacy Survey UKIDSS/UDS field: Source catalogue and properties
• High-resolution radio observations of submillimetre galaxies
• The dust un-biased cosmic star formation history from the 20 cm VLA-COSMOS survey
• The MeerKAT International GHz Tiered Extragalactic Exploration (MIGHTEE) Survey
• An ALMA survey of submillimetre galaxies in the Extended Chandra Deep Field South: radio properties and the far-infrared/radio correlation
• The Spectral Energy Distribution of Powerful Starburst Galaxies I: Modelling the Radio Continuum
• Radio continuum size evolution of star-forming galaxies over 0.35 < z < 2.25
• An evolution of the IR-Radio correlation at very low flux densities?
• The eMERGE Survey I: Very Large Array 5.5 GHz observations of the GOODS-North Field
• Tracing cool molecular gas and star formation on $\sim 100$pc scales within a $z=2.3$ galaxy
• An insight into the extragalactic transient and variable microJy radio sky across multiple decades
• Using VO tools to investigate distant radio starbursts hosting obscured AGN in the HDF(N) region
• A Submillimeter Perspective on the GOODS Fields (SUPER GOODS) - II. The High Radio Power Population in the GOODS-N

Cited by in corpus (2)

• The MOSDEF Survey: Calibrating the relationship between H$\alpha$ star-formation rate and radio continuum luminosity at $1.4<z<2.6$
• Searching for obscured AGN in z $\sim$ 2 submillimetre galaxies