ALMA spectroscopic survey in the Hubble Ultra Deep Field: survey description
- Max-Planck Institut für Astronomie, Königstuhl 17, D-69117, Heidelberg (Germany)
- Núcleo de Astronomía, Facultad de Ingeniería, Universidad Diego Portales, Av. Ejército 441, Santiago (Chile)
- National Radio Astronomy Observatory, Pete V. Domenici Array Science Center, P.O. Box O, Socorro, NM 87801 (United States)
- Leiden Observatory, Leiden University, P.O. Box 9513, NL2300 RA Leiden (Netherlands)
- Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, Victoria 3122 (Australia)
- Laboratoire AIM, CEA/DSM-CNRS-Universite Paris Diderot, Irfu/Service d’Astrophysique, CEA Saclay, Orme des Merisiers, F-91191 Gif-sur-Yvette cedex (France)
- European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748, Garching (Germany)
- Cornell University, 220 Space Sciences Building, Ithaca, NY 14853 (United States)
- 6 Centre for Extragalactic Astronomy, Department of Physics, Durham University, South Road, Durham, DH1 3LE (United Kingdom)
- Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany)
- Departamento de Ciencias Físicas, Universidad Andres Bello, Fernandez Concha 700, Las Condes, Santiago (Chile)
- Université Lyon 1, 9 Avenue Charles André, F-69561 Saint Genis Laval (France)
We present the rationale for and the observational description of ASPECS: the ALMA SPECtroscopic Survey in the Hubble Ultra-Deep Field (UDF), the cosmological deep field that has the deepest multi-wavelength data available. Our overarching goal is to obtain an unbiased census of molecular gas and dust continuum emission in high-redshift (z > 0.5) galaxies. The ∼1′ region covered within the UDF was chosen to overlap with the deepest available imaging from the Hubble Space Telescope. Our ALMA observations consist of full frequency scans in band 3 (84–115 GHz) and band 6 (212–272 GHz) at approximately uniform line sensitivity (L{sub CO}{sup ′} ∼ 2 × 10{sup 9} K km s{sup −1} pc{sup 2}), and continuum noise levels of 3.8 μJy beam{sup −1} and 12.7 μJy beam{sup −1}, respectively. The molecular surveys cover the different rotational transitions of the CO molecule, leading to essentially full redshift coverage. The [C ii] emission line is also covered at redshifts 6.0<8.0. We present a customized algorithm to identify line candidates in the molecular line scans and quantify our ability to recover artificial sources from our data. Based on whether multiple CO lines are detected, and whether optical spectroscopic redshifts as well as optical counterparts exist, we constrain the most likely line identification. We report 10 (11) CO line candidates in the 3 mm (1 mm) band, and our statistical analysis shows that <4 of these (in each band) are likely spurious. Less than one-third of the total CO flux in the low-J CO line candidates are from sources that are not associated with an optical/NIR counterpart. We also present continuum maps of both the band 3 and band 6 observations. The data presented here form the basis of a number of dedicated studies that are presented in subsequent papers.
- OSTI ID:
- 22868348
- Journal Information:
- Astrophysical Journal, Vol. 833, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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