Calibration of ALMA as a phased array: ALMA observations during the 2017 VLBI campaign

Abstract

We present a detailed description of the special procedures for calibration and quality assurance of Atacama Large Millimeter/submillimeter Array (ALMA) observations in Very Long Baseline Interferometry (VLBI) mode. These procedures are required to turn the phased ALMA array into a fully calibrated VLBI station. As an illustration of these methodologies, we present full-polarization observations carried out with ALMA as a phased array at 3mm (Band 3) and 1.3mm (Band 6) as part of Cycle-4. These are the first VLBI science observations conducted with ALMA and were obtained during a 2017 VLBI campaign in concert with other telescopes worldwide as part of the Global mm-VLBI Array (GMVA, April 1-3) and the Event Horizon Telescope (EHT, April 5-11) in ALMA Bands 3 and 6, respectively.

39 pages, 20 figures, 10 tables, accepted by PASP

References in corpus (8)

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• First M87 Event Horizon Telescope Results. II. Array and Instrumentation
• First M87 Event Horizon Telescope Results. III. Data Processing and Calibration
• Event-horizon-scale structure in the supermassive black hole candidate at the Galactic Centre
• Jet Launching Structure Resolved Near the Supermassive Black Hole in M87
• Radio observations of active galactic nuclei with mm-VLBI
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Cited by in corpus (39)

• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole
• First M87 Event Horizon Telescope Results. II. Array and Instrumentation
• First M87 Event Horizon Telescope Results. III. Data Processing and Calibration
• First Sagittarius A* Event Horizon Telescope Results. III: Imaging of the Galactic Center Supermassive Black Hole
• First Sagittarius A* Event Horizon Telescope Results. II. EHT and Multi-wavelength Observations, Data Processing, and Calibration
• First Sagittarius A* Event Horizon Telescope Results. IV. Variability, Morphology, and Black Hole Mass
• Event Horizon Telescope observations of the jet launching and collimation in Centaurus A
• Millimeter light curves of Sagittarius A* observed during the 2017 Event Horizon Telescope campaign
• Orbital motion near Sagittarius A* -- Constraints from polarimetric ALMA observations
• First M87 Event Horizon Telescope Results. IX. Detection of Near-horizon Circular Polarization
• The ALMA Interferometric Pipeline Heuristics
• Monitoring the Morphology of M87* in 2009-2017 with the Event Horizon Telescope
• Resolving the inner parsec of the blazar J1924-2914 with the Event Horizon Telescope
• Collimation of the relativistic jet in the quasar 3C 273
• Polarization calibration techniques for new-generation VLBI
• Broadband Multi-wavelength Properties of M87 during the 2018 EHT Campaign including a Very High Energy Flaring Episode
• The Galactic Center as a laboratory for theories of gravity and dark matter
• First Very Long Baseline Interferometry Detections at 870μm
• Unravelling the Innermost Jet Structure of OJ 287 with the First GMVA+ALMA Observations
• The Event Horizon Telescope Image of the Quasar NRAO 530
• A D-term Modeling Code (DMC) for simultaneous calibration and full-Stokes imaging of very long baseline interferometric data
• Ordered magnetic fields around the 3C 84 central black hole
• The internal Faraday screen of Sagittarius A*
• A Characterization of the ALMA Phasing System at 345 GHz
• MeqSilhouette v2: Spectrally-resolved polarimetric synthetic data generation for the Event Horizon Telescope
• A multi-frequency study of sub-parsec jets with the Event Horizon Telescope
• A first search of transients in the Galactic Center from 230 GHz ALMA observations
• The putative center in NGC 1052
• Charting Circumstellar Chemistry of Carbon-rich AGB Stars: I. ALMA 3 mm spectral surveys
• First polarization study of the M87 jet and active galactic nuclei at submillimeter wavelengths with ALMA
• Deep learning inference with the Event Horizon Telescope I. Calibration improvements and a comprehensive synthetic data library
• Robust analysis of differential Faraday Rotation based on interferometric closure observables
• Towards an astronomical use of new-generation geodetic observations. I. From the correlator to full-polarization images
• Kilogauss magnetic field and jet dynamics in the quasar NRAO 530
• The science case and challenges of space-borne sub-millimeter interferometry
• Very-Long Baseline Interferometry Imaging with Closure Invariants using Conditional Image Diffusion
• First Very Long Baseline Interferometry Fringe Detection at 690GHz
• Full-polarization millimeter wavelength variability of Sagittarius A* during the 2018 EHT campaign