THE 2014 ALMA LONG BASELINE CAMPAIGN: AN OVERVIEW

Alma Partnership , E. B. Fomalont (1) , C. Vlahakis , S. Corder , A. Remijan (1) , D. Barkats (2) , R. Lucas , T. R. Hunter , C. L. Brogan , Y. Asaki , S. Matsushita , W. R. F. Dent , R. E. Hills , N. Phillips , A. M. S. Richards , P. Cox (3) , R. Amestica , D. Broguiere , W. Cotton , A. S. Hales , R. Hiriart , A. Hirota , J. A. Hodge (4) , C. M. V. Impellizzeri , J. Kern (5) , R. Kneissl , E. Liuzzo , N. Marcelino (6) , R. Marson , A. Mignano (7) , K. Nakanishi , B. Nikolic , J. E. Perez , L. M. Pérez , I. Toledo , R. Aladro , B. Butler , J. Cortes (1) , P. Cortes (1) , V. Dhawan , J. Di Francesco , D. Espada , F. Galarza , D. Garcia-Appadoo , L. Guzman-Ramirez , E. M. Humphreys , T. Jung , S. Kameno , R. A. Laing , S. Leon (8) , J. Mangum , G. Marconi , H. Nagai , L.-A. Nyman (9) , M. Radiszcz , J. A. Rodón , T. Sawada (10) , S. Takahashi , R. P. J. Tilanus , T. Van Kempen , B. Vila Vilaro , L. C. Watson (11) , T. Wiklind (12) , F. Gueth (13) , K. Tatematsu , A. Wootten , A. Castro-Carrizo , E. Chapillon (14) , G. Dumas (13) , I. de Gregorio-Monsalvo , H. Francke , J. Gallardo (15) , J. Garcia (16) , S. Gonzalez (17) , J. E. Hibbard , T. Hill , T. Kaminski (18) , A. Karim , M. Krips (13) , Y. Kurono , C. Lopez (2) , S. Martin (19) , L. Maud , F. Morales (20) , V. Pietu (13) , K. Plarre , G. Schieven , L. Testi (21, 22) , L. Videla (23) , E. Villard (24, 25) , N. Whyborn , M. A. Zwaan , F. Alves (26) , P. Andreani , A. Avison , M. Barta (27) , F. Bedosti , G. J. Bendo , F. Bertoldi (28) , M. Bethermin , A. Biggs , J. Boissier (13) , J. Brand , S. Burkutean , V. Casasola (7) , J. Conway , L. Cortese (29) , B. Dabrowski (30) , T. A. Davis (31) , M. Diaz Trigo , F. Fontani , R. Franco-Hernandez , G. Fuller (32) , R. Galvan Madrid , A. Giannetti , A. Ginsburg , S. F. Graves , E. Hatziminaoglou , M. Hogerheijde (33) , P. Jachym , I. Jimenez Serra , M. Karlicky (27) , P. Klaasen , M. Kraus (34) , D. Kunneriath , C. Lagos , S. Longmore (35) , S. Leurini (28) , M. Maercker , B. Magnelli , I. Marti Vidal , M. Massardi (7) , A. Maury (36) , S. Muehle , S. Muller (37) , T. Muxlow , E. O’gorman , R. Paladino , D. Petry , J. Pineda (38) , S. Randall , J. S. Richer , A. Rossetti (39) , A. Rushton , K. Rygl , A. Sanchez Monge (40) , R. Schaaf , P. Schilke (41) , T. Stanke , M. Schmalzl , F. Stoehr (29) , S. Urban (42) , E. Van Kampen , W. Vlemmings , K. Wang , W. Wild , Y. Yang , S. Iguchi , T. Hasegawa , M. Saito , J. Inatani , N. Mizuno (2, 43) , S. Asayama , G. Kosugi , K.-I. Morita , K. Chiba , S. Kawashima , S. K. Okumura , N. Ohashi (44) , R. Ogasawara , S. Sakamoto (45) , T. Noguchi , Y.-D. Huang (46) , S.-Y. Liu (47) , F. Kemper , P. M. Koch (48) , M.-T. Chen , Y. Chikada , M. Hiramatsu , D. Iono , M. Shimojo , S. Komugi , J. Kim (49, 50) , A.-R. Lyo , E. Muller (51) , C. Herrera (52) , R. E. Miura (53) , J. Ueda , J. Chibueze , Y.-N. Su , A. Trejo-Cruz , K.-S. Wang , H. Kiuchi , N. Ukita , M. Sugimoto (54) , R. Kawabe , M. Hayashi (55) , S. Miyama , P. T. P. Ho , N. Kaifu , M. Ishiguro (56) , A. J. Beasley , S. Bhatnagar (57) , J. A. Braatz Iii , D. G. Brisbin , N. Brunetti , C. Carilli (58) , J. H. Crossley , L. D’addario , J. L. Donovan Meyer (59) , D. T. Emerson (60) , A. S. Evans (61) , P. Fisher , K. Golap , D. M. Griffith (62) , A. E. Hale (63) , D. Halstead , E. J. Hardy , M. C. Hatz , M. Holdaway , R. Indebetouw , P. R. Jewell , A. A. Kepley , D.-C. Kim , M. D. Lacy , A. K. Leroy (64) , H. S. Liszt (1) , C. J. Lonsdale , B. Matthews , M. Mckinnon , B. S. Mason (65) , G. Moellenbrock , A. Moullet , S. T. Myers , J. Ott (66) , A. B. Peck , J. Pisano , S. J. E. Radford , W. T. Randolph , U. Rao Venkata , M. G. Rawlings , R. Rosen , S. L. Schnee , K. S. Scott , N. K. Sharp , K. Sheth , R. S. Simon (1) , T. Tsutsumi , S. J. Wood (67)

1 NRAO - National Radio Astronomy Observatory
2 JAO - Joint ALMA Observatory
3 Institute for Ethnomedicine
4 MPIA - Max-Planck-Institut für Astronomie
5 CMTC - Chimie des métaux de transition et catalyse
6 IRA - Istituto di Radioastronomia [Bologna]
7 INAF - Istituto Nazionale di Astrofisica
8 IJM (UMR_7592) - Institut Jacques Monod
9 ESO
10 Department of Organic and Polymeric Materials
11 Biogeochemistry Research Centre
12 Onsala Space Observatory
13 IRAM - Institut de RadioAstronomie Millimétrique
14 AMOR 2015
15 Departamento de Analisis Matematico
16 URZF - Unité de recherche Zoologie Forestière
17 IFPEN - IFP Energies nouvelles
18 Fastopt GmbH, D-20357 Hamburg, Germany
19 MAP5 - UMR 8145 - Mathématiques Appliquées Paris 5
20 Departament de Ecologia, Universitat d'Alacant
21 ESO
22 OAA - INAF - Osservatorio Astrofisico di Arcetri
23 Faculty of Medicine
24 UPMC - Université Pierre et Marie Curie - Paris 6
25 ICAN - Unité de Recherche sur les Maladies Cardiovasculaires, du Métabolisme et de la Nutrition = Research Unit on Cardiovascular and Metabolic Diseases
26 LGEP - Laboratoire de génie électrique de Paris
27 ASU / CAS - Astronomical Institute of the Czech Academy of Sciences
28 MPIFR - Max-Planck-Institut für Radioastronomie
29 ESO - European Southern Observatory
30 Northern Illinois University
31 Centre for Astrophysics Research [Hatfield]
32 JBCA - Jodrell Bank Centre for Astrophysics
33 FL - foreign laboratories
34 Departements of Medicine and Microbiology
35 Swinburne University of Technology (Hawthorn campus)
36 SPACE - San Pedro de Atacama Celestial Explorations
37 GE Healthcare - General Electric Medical Systems [Buc]
38 LRP - Laboratoire de Radiopathologie
39 UNIMI - Università degli Studi di Milano = University of Milan
40 Altération génétique des cancers, chimioprévention et réponse thérapeutique
41 Physikalisches Institut [Köln]
42 Ministère de la santé
43 NAOJ - National Astronomical Observatory of Japan
44 NIMS - National Institute for Materials Science
45 EAC - Espaces acoustiques et cognitifs
46 DMA - Département de Mathématiques et Applications - ENS Paris
47 Department of Chemistry and Biochemistry [Bern]
48 Academia Sinica
49 Department of Marine Organic Biogeochemistry
50 Faculty of Geosciences, Utrecht University
51 BMI - EPFL - Brain Mind Institute
52 DIE - Departamento de Ingenieria Eléctrica
53 Laboratório de Bioinformática
54 UTokyo - Graduate School of Engineering [The Univ of Tokyo]
55 Kyushu University
56 Mitsubishi Research Institute, Inc.
57 CSA - Department of Computer Science and Automation [Bangalore]
58 NRAO - National Radio Astronomy Observatory [Socorro]
59 Occupational Physiology Laboratory (Vandœuvre-Les -Nancy, France)
60 STFC - Computational Science and Engineering Department [Daresbury]
61 UCL - University College of London [London]
62 CAC - Centre for Atmospheric Chemistry [Wollongong]
63 Safety science group
64 CIC-IT Grenoble (CIT803) - Centre d'Investigation Clinique - Innovation Technologique - INSERM - CHU de Grenoble
65 Northern Research Station
66 Department of Helsinki Institute for Information Technology Communications and Networking
67 University of Washington [Seattle]

A major goal of the Atacama Large Millimeter/submillimeter Array (ALMA) is to make accurate images with resolutions of tens of milliarcseconds, which at submillimeter (submm) wavelengths requires baselines up to ~15 km. To develop and test this capability, a Long Baseline Campaign (LBC) was carried out from September to late November 2014, culminating in end-to-end observations, calibrations, and imaging of selected Science Verification (SV) targets. This paper presents an overview of the campaign and its main results, including an investigation of the short-term coherence properties and systematic phase errors over the long baselines at the ALMA site, a summary of the SV targets and observations, and recommendations for science observing strategies at long baselines. Deep ALMA images of the quasar 3C138 at 97 and 241 GHz are also compared to VLA 43 GHz results, demonstrating an agreement at a level of a few percent. As a result of the extensive program of LBC testing, the highly successful SV imaging at long baselines achieved angular resolutions as fine as 19 mas at ~350 GHz. Observing with ALMA on baselines of up to 15 km is now possible, and opens up new parameter space for submm astronomy.

Mots clés: instrumentation: interferometers; techniques: high angular resolution; telescopes; techniques: interferometric; submillimeter: general

Domaines: Cosmologie et astrophysique extra-galactique [astro-ph.CO]

Alma Partnership, E. B. Fomalont, C. Vlahakis, S. Corder, A. Remijan, et al.. THE 2014 ALMA LONG BASELINE CAMPAIGN: AN OVERVIEW. The Astrophysical journal letters, 2015, 808 (1), pp.id. L1. ⟨10.1088/2041-8205/808/1/L1⟩. ⟨hal-01144571⟩