An Overview of the 2014 ALMA Long Baseline Campaign

Abstract

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.

11 pages, 7 figures, 2 tables; accepted for publication in the Astrophysical Journal Letters; this version with small changes to affiliations

References in corpus (2)

• First Results from High Angular Resolution ALMA Observations Toward the HL Tau Region
• ALMA Long Baseline Observations of the Strongly Lensed Submillimeter Galaxy HATLAS J090311.6+003906 at z=3.042

Cited by in corpus (62)

• Dust and Gas in the disc of HL Tauri: Surface density, dust settling, and dust-to-gas ratio
• 2018 Census of Interstellar, Circumstellar, Extragalactic, Protoplanetary Disk, and Exoplanetary Molecules
• Detection of lensing substructure using ALMA observations of the dusty galaxy SDP.81
• High-redshift star formation in the ALMA era
• The Radial Distribution of Dust Particles in the HL Tau Disk from ALMA and VLA Observations
• Dynamics of cluster-forming hub-filament systems: The case of the high-mass star-forming complex Monoceros R2
• FIREbox: Simulating galaxies at high dynamic range in a cosmological volume
• The physical and chemical structure of Sagittarius B2. II. Continuum millimeter emission of SgrB2(M) and SgrB2(N) with ALMA
• Candidate Gravitationally Lensed Dusty Star-forming Galaxies in the Herschel Wide Area Surveys
• Opportunities for Fundamental Physics Research with Radioactive Molecules
• The GRAVITY Young Stellar Object survey -- I. Probing the disks of Herbig Ae/Be stars in terrestrial orbits
• STATCONT: A statistical continuum level determination method for line-rich sources
• An observational study of dust nucleation in Mira ($o$ Ceti): I. Variable features of AlO and other Al-bearing species
• ALMA imaging of SDP.81 - II. A pixelated reconstruction of the CO emission lines
• Resolving the extended atmosphere and the inner wind of Mira ($o$ Ceti) with long ALMA baselines
• The Physical and chemical structure of Sagittarius B2 -- IV. Converging filaments in the high-mass cluster forming region Sgr B2(N)
• Planets Around Low-Mass Stars (PALMS). VI. Discovery of a Remarkably Red Planetary-Mass Companion to the AB Dor Moving Group Candidate 2MASS J22362452+4751425
• High-resolution ALMA Observations of SDP.81. II. Molecular Clump Properties of a Lensed Submillimeter Galaxy at z=3.042
• The effect of magnetic field modifications on the modulation of cosmic rays in the heliosphere
• Magnetically Induced Disk Winds and Transport in the HL Tau Disk
• ALMA Long Baseline Campaigns: Phase Characteristics of Atmosphere at Long Baselines in the Millimeter and Submillimeter Wavelengths
• Model-independent constraints on Lorentz invariance violation: implication from updated Gamma-ray burst observations
• An observational study of dust nucleation in Mira ($o$ Ceti): II. Titanium oxides are negligible for nucleation at high temperatures
• ATOMIUM: ALMA tracing the origins of molecules in dust forming oxygen rich M-type stars: Motivation, sample, calibration, and initial results
• ALMA Imprint of Intergalactic Dark Structures in the Gravitational Lens SDP.81
• Toward Precision Black Hole Masses with ALMA: NGC 1332 as a Case Study in Molecular Disk Dynamics
• The effect of non-equilibrium metal cooling on the interstellar medium
• The $\rho$ Oph region revisited with Gaia EDR3
• SALT observations of the Chromospheric Activity of Transiting Planet Hosts: Mass Loss and Star Planet Interactions
• A combined multiwavelength VLA/ALMA/Chandra study unveils the complex magnetosphere of the B-type star HR5907
• Possible Atmospheric Diversity of Low Mass Exoplanets, some Central Aspects
• New Measurements of the Radio Photosphere of Mira based on Data from the JVLA and ALMA
• Phase correction for ALMA - Investigating water vapour radiometer scaling:The long-baseline science verification data case study
• ALMA High-frequency Long Baseline Campaign in 2017: Band-to-band Phase Referencing in Submillimeter Waves
• A Dwarf Protoplanetary Disk around XZ Tau B
• Interferometric Evidence for Quantum Heated Particles in the Inner Region of Protoplanetary Disks around Herbig Stars
• Widespread HCN maser emission in carbon-rich evolved stars
• The physical and chemical structure of Sagittarius B2. III. Radiative transfer simulations of the hot core SgrB2(M) for methyl cyanide
• The radio continuum spectrum of Mira A and Mira B up to submillimeter wavelengths
• Search for sub-millimeter H2O masers in active galaxies - the detection of a 321 GHz H2O maser in NGC4945
• Origin and kinematics of the eruptive flow from XZ Tau revealed by ALMA
• Numerical Simulations of Torsional Alfvén Waves in Axisymmetric Solar Magnetic Flux Tubes
• The GRAVITY Young Stellar Object survey VIII. Gas and dust faint inner rings in the hybrid disk of HD141569
• Analysis of antenna position measurements and weather station network data during the ALMA Long Baseline Campaign of 2015
• The physical and chemical structure of Sagittarius B2 VIIIa. Dust and ionized gas contributions to the full molecular line survey of 47 hot cores
• Can chondrules be produced by the interaction of Jupiter with the protosolar disk?
• Gap formation by inclined massive planets in locally isothermal three-dimensional discs
• Feasibility of detecting shadows in disks induced by infall
• Precipitable water vapour measurement using GNSS data in the Atacama Desert for millimetre and submillimetre astronomical observations
• The physical and chemical structure of Sagittarius B2, VIII. Full molecular line survey of hot cores
• ALMA High-frequency Long-baseline Campaign in 2017: A Comparison of the Band-to-band and In-band Phase Calibration Techniques and Phase-calibrator Separation Angles
• Revealing new features of the millimetre emission of the circumbinary envelope of Mira Ceti
• TEMPus VoLA: the Timed Epstein Multi-pressure Vessel at Low Accelerations
• ALMA Band-to-band Phase Referencing: Imaging Capabilities on Long Baselines and High Frequencies
• Modelling H${}_2$ and its effects on star formation using a joint implementation of GADGET-3 and KROME
• Simulations of Small Solid Accretion onto Planetesimals in the Presence of Gas
• Robust analysis of differential Faraday Rotation based on interferometric closure observables
• Terahertz Atmospheric Windows for High Angular Resolution Terahertz Astronomy from Dome A
• CHARA/MIRC-X -- a high-sensitive six telescope interferometric imager concept, commissioning, and early science
• The asymmetric structure of the inner disc around HD 142527 A with VLTI/MATISSE
• Advanced Gain Calibration Techniques in Radio Interferometry
• How two-dimensional are planet-disc interactions? II. Radiation hydrodynamics and suitable cooling prescriptions