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ALMA Spectroscopic Survey in the Hubble Ultra Deep Field: Survey Description

Walter, Fabian (2016) ALMA Spectroscopic Survey in the Hubble Ultra Deep Field: Survey Description. Astrophysical Journal, 833 (1). Art. No. 67. ISSN 0004-637X. doi:10.3847/1538-4357/833/1/67.

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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’_(CO) ~ 2 × 10^9 K km s^(−1) pc^2), and continuum noise levels of 3.8 μJy beam^(−1) and 12.7 μJy beam^(−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 < z < 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.

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URLURL TypeDescription Paper
Walter, Fabian0000-0003-4793-7880
Additional Information:© 2016 The American Astronomical Society. Received 2016 May 3; revised 2016 July 22; accepted 2016 July 26; published 2016 December 8. We thank the referee for a constructive report that helped improve the presentation of the data. F.W., I.R.S., and R.J.I. acknowledge support through ERC grants COSMIC-DAWN, DUSTYGAL, and COSMICISM, respectively. M.A. acknowledges partial support from FONDECYT through grant 1140099. D.R. acknowledges support from the National Science Foundation under grant number AST-#1614213 to Cornell University. F.E.B. and L.I. acknowledge Conicyt grants Basal-CATA PFB-06/2007 and Anilo ACT1417. F.E.B. also acknowledges support from FONDECYT Regular 1141218 (FEB), and the Ministry of Economy, Development, and Tourism's Millennium Science Initiative through grant IC120009, awarded to The Millennium Institute of Astrophysics, MAS. I.R.S. also acknowledges support from STFC (ST/L00075X/1) and a Royal Society/Wolfson Merit award. Support for R.D. and B.M. was provided by the DFG priority program 1573 "The physics of the interstellar medium." A.K. and F.B. acknowledge support by the Collaborative Research Council 956, sub-project A1, funded by the Deutsche Forschungsgemeinschaft (DFG). L.I. acknowledges Conict grants Basal-CATA PFB-06/2007 and Anilo ACT1417. R.J.A. was supported by FONDECYT grant number 1151408. This paper makes use of the following ALMA data: 2013.1.00146.S and 2013.1.00718.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), NSC and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO, and NAOJ. The 3 mm-part of ALMA project had been supported by the German ARC.
Funding AgencyGrant Number
European Research Council (ERC)UNSPECIFIED
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)1140099
Comisión Nacional de Investigación Científica y Tecnológica (CONICYT)Anilo ACT1417
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)1141218
Iniciativa Científica Milenio del Ministerio de Economía, Fomento y TurismoIC120009
Science and Technology Facilities Council (STFC)ST/L00075X/1
Deutsche Forschungsgemeinschaft (DFG)1573
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)1151408
Subject Keywords:galaxies: evolution – galaxies: ISM – galaxies: high-redshift – galaxies: formation – surveys
Issue or Number:1
Record Number:CaltechAUTHORS:20161212-100621401
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Official Citation:Fabian Walter et al 2016 ApJ 833 67
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:72717
Deposited By: Tony Diaz
Deposited On:12 Dec 2016 18:18
Last Modified:11 Nov 2021 05:05

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