ALMAAtacama Large Millimeter/submillimeter Array


Dr. Ronald Stark
Sterrenwachtlaan 11, 2311 GP Leiden
ESO (Europe), NRAO (North America), NAOJ (East Asia)

The Atacama Large Millimeter/submillimeter Array (ALMA) is a single telescope of revolutionary design and is composed of 66 high precision antennas located on the Chajnantor plateau at 5000 meters altitude in northern Chile. It enables transformational research into the physics and chemistry of the cold Universe, the chemistry in star- and planet formation, probes the formation of stars and galaxies out to high redshift, and directly images the formation of planets. ALMA is an international partnership of the European Southern Observatory (ESO), the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. NOVA is involved in ALMA through ESO, is responsible for the construction of heterodyne receivers, and hosts the ALMA Regional Center node Allegro which is the point of contact for any type of NL user support, from first aid with proposal preparation to optimally exploiting ALMA data.

ALMA comprises a giant array of fifty 12-m antennas, which can be configured to achieve baselines up to 16 km. An additional compact array of 16 antennas greatly enhances ALMA's ability to image extended sources. It is equipped with state-of-the-art receivers for continuum observations and spectroscopy of molecular lines that cover all the atmospheric windows from 30 GHz up to 1 THz. The ALMA correlator, a specialised computer that combines the information received by the antennas, can perform 17 Peta operations per second. ALMA produces 200 TB/year in raw data, out of which a similar amount of data products are distilled. The processing of data involves a (temporary) 10x increase in data volume. Central ALMA data processing is carried out on 60-70 blades with 16 cores of 256 GB memory each, and is heavily IO and memory limited.

NOVA is a preferred partner of ESO for the development and construction of ALMA receivers. Together with Onsala Observatory in Sweden and other European partners, it has constructed a total of 73 receivers for Band 5, the 163 – 211 GHz wavelength range, as well as for Band 9 (600 - 720 GHz). Currently NOVA is leading an international consortium for the construction of receivers for Band 2 (67 - 116 GHz).

A scientific data pipeline has been developed by the ALMA Regional Centres, including NOVA/Allegro (see below), and is constantly evolving with the goal of performing automated data processing before delivery to the user. The ALMA Science Portal is the main ALMA web resource for the entire ALMA Science Community. It contains all the information and software necessary to prepare observing proposals, access data through the Science Archive and to reduce ALMA data.

The ALMA Regional Centres (ARCs) provide the interface between ALMA and the Science Communities of the three regions (Europe, North America and East Asia). The scientific communities of the ESO member states are supported by the European ARC. The European ARC consists of a network of nodes distributed throughout Europe that are coordinated by a central node located at ESO. The ARC is the point of contact for any type of user support, from first aid with proposal preparation to optimally exploiting ALMA data. Allegro is the ARC node located in the Netherlands. It provides expert user support across all stages of NL ALMA projects. Allegro hosts advanced computing (150 CPU cores) and data storage (800 TB) to support NL users in data processing. Allegro serves as the NL point of contact to ALMA, and actively contributes to ALMA by developing advanced operational and data-processing methods

The antennas were completed in 2014 and ALMA consistently produces unique and spectacular results. The fields in which it has delivered hitherto its most outstanding results include: Cosmology and the high redshift universe, Galaxies and galactic nuclei (including the first detection of the shadow of a Black Hole), the interstellar medium, star formation and astrochemistry, Planet-forming disks, Stellar evolution; and the Solar system. The total number of astronomical publications based on observations performed with ALMA is at this moment close to 2000.

Aansluiting bij strategische ontwikkelingen
High Tech Systemen en Materialen
Oorsprong van het leven- op aarde en in het heelal
Bouwstenen van materie en fundamenten van ruimte en tijd
Waardecreatie door verantwoorde toegang tot en gebruik van big data