University of Hertfordshire

From the same journal

From the same journal

GOODS-ALMA: 1.1 mm galaxy survey - I. Source catalogue and optically dark galaxies

Research output: Contribution to journalArticlepeer-review

  • M. Franco
  • D. Elbaz
  • M. Béthermin
  • B. Magnelli
  • C. Schreiber
  • L. Ciesla
  • M. Dickinson
  • N. Nagar
  • J. Silverman
  • E. Daddi
  • D. M. Alexander
  • T. Wang
  • M. Pannella
  • E. Le Floc'h
  • A. Pope
  • M. Giavalisco
  • A. J. Maury
  • F. Bournaud
  • R. Chary
  • R. Demarco
  • And 19 others
  • H. Ferguson
  • S. L. Finkelstein
  • H. Inami
  • D. Iono
  • S. Juneau
  • G. Lagache
  • R. Leiton
  • L. Lin
  • G. Magdis
  • H. Messias
  • K. Motohara
  • J. Mullaney
  • K. Okumura
  • C. Papovich
  • J. Pforr
  • W. Rujopakarn
  • M. Sargent
  • X. Shu
  • L. Zhou
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Original languageEnglish
Article numberA152
Number of pages26
JournalAstronomy & Astrophysics
Volume620
Early online date11 Dec 2018
DOIs
Publication statusE-pub ahead of print - 11 Dec 2018

Abstract

We present a 69 arcmin$^2$ ALMA survey at 1.1mm, GOODS-ALMA, matching the deepest HST-WFC3 H-band part of the GOODS-South field. We taper the 0"24 original image with a homogeneous and circular synthesized beam of 0"60 to reduce the number of independent beams - thus reducing the number of purely statistical spurious detections - and optimize the sensitivity to point sources. We extract a catalogue of galaxies purely selected by ALMA and identify sources with and without HST counterparts down to a 5$\sigma$ limiting depth of H=28.2 AB (HST/WFC3 F160W). ALMA detects 20 sources brighter than 0.7 mJy in the 0"60 tapered mosaic (rms sensitivity =0.18 mJy/beam) with a purity greater than 80%. Among these detections, we identify three sources with no HST nor Spitzer-IRAC counterpart, consistent with the expected number of spurious galaxies from the analysis of the inverted image; their definitive status will require additional investigation. An additional three sources with HST counterparts are detected either at high significance in the higher resolution map, or with different detection-algorithm parameters ensuring a purity greater than 80%. Hence we identify in total 20 robust detections. Our wide contiguous survey allows us to push further in redshift the blind detection of massive galaxies with ALMA with a median redshift of $z$=2.92 and a median stellar mass of M$_{\star}$ = 1.1 $\times 10^{11}$M$_\odot$. Our sample includes 20% HST-dark galaxies (4 out of 20), all detected in the mid-infrared with IRAC. The near-infrared based photometric redshifts of two of them $z\sim$4.3 and 4.8) suggest that these sources have redshifts $z$>4. At least 40% of the ALMA sources host an X-ray AGN, compared to 14% for other galaxies of similar mass and redshift. The wide area of our ALMA survey provides lower values at the bright end of number counts than single-dish telescopes

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