The e-MERGE Survey (e-MERLIN Galaxy Evolution Survey): overview and survey description

Venturi, T.; Varenius, E.; Swinbank, A.M.; Simpson, J.M.; Simpson, C.; Serjeant, S.; Sargent, M.T.; Röttgering, H.J.A.; Richards, A.M.S.; Pérez-Torres, M.A.; Pearson, C.; Njeri, A.; Murphy, E.J.; Morabito, L.K.; Koopmans, L.V.E.; Knudsen, K.K.; Kneib, J-P.; Ibar, E.; Garrett, M.A.; Garratt, T.K.; Chen, H.; Coppin, K.; Chapman, S.C.; Biggs, A.D.; Best, P.N.; Bacon, D.; Argo, M.K.; Guidetti, D.; Bondi, M.; Prandoni, I.; Jarvis, M.J.; Ivison, R.J.; Garrington, S.T.; McHardy, I.M.; Smail, I.; Beswick, R.J.; Wrigley, N.H.; Radcliffe, J.F.; Thomson, A.P.; Muxlow, T.W.B.

Abstract

We present an overview and description of the e-MERGE Survey (e-MERLIN Galaxy Evolution Survey) Data Release 1 (DR1), a large program of high-resolution 1.5-GHz radio observations of the GOODS-N field comprising ∼140 h of observations with enhanced-Multi-Element Remotely Linked Interferometer Network (e-MERLIN) and ∼40 h with the Very Large Array (VLA). We combine the long baselines of e-MERLIN (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 (⁠∼1.5μ Jy beam−1), angular resolution (0.2–0.7 arcsec) and field-of-view (∼15 × 15 arcmin2) to detect and spatially resolve star-forming galaxies and active galactic nucleus (AGN) at z ≳ 1. The goal of e-MERGE 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 an ∼20-yr baseline and the development of new point spread function/primary beam models to seamlessly merge e-MERLIN and VLA data in the uv plane. We present early science results, including measurements of the luminosities and/or linear sizes of ∼500 galaxies selected at 1.5 GHz. In combination with deep Hubble Space Telescope observations, we measure a mean radio-to-optical size ratio of re-MERGE/rHST ∼ 1.02 ± 0.03, suggesting that in most high-redshift galaxies, the ∼GHz continuum emission traces the stellar light seen in optical imaging. This is the first in a series of papers that will explore the ∼kpc-scale radio properties of star-forming galaxies and AGN in the GOODS-N field observed by e-MERGE DR1.

Citation

Venturi, T., Varenius, E., Swinbank, A., Simpson, J., Simpson, C., Serjeant, S., Sargent, M., Röttgering, H., Richards, A., Pérez-Torres, M., Pearson, C., Njeri, A., Murphy, E., Morabito, L., Koopmans, L., Knudsen, K., Kneib, J.-P., Ibar, E., Garrett, M., Garratt, T., …Muxlow, T. (2020). The e-MERGE Survey (e-MERLIN Galaxy Evolution Survey): overview and survey description. Monthly Notices of the Royal Astronomical Society, 495(1), 1188-1208. https://doi.org/10.1093/mnras/staa1279

• Journal Article Type: Article
• Acceptance Date: May 5, 2020
• Online Publication Date: May 8, 2020
• Publication Date: 2020-06
• Deposit Date: Jun 24, 2020
• Publicly Available Date: Jun 24, 2020
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Royal Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 495
• Issue: 1
• Pages: 1188-1208
• DOI: https://doi.org/10.1093/mnras/staa1279
• Public URL: https://durham-repository.worktribe.com/output/1299164