The ALMA Regional Centres (ARCs) form the interface between the ALMA observatory and the user community from
the proposal preparation stage to the delivery of data and their subsequent analysis. The ARCs provide critical services to
both the ALMA operations in Chile and to the user community. These services were split by the ALMA project into core
and additional services. The core services are financed by the ALMA operations budget and are critical to the successful
operation of ALMA. They are contractual obligations and must be delivered to the ALMA project. The additional
services are not funded by the ALMA project and are not contractual obligations, but are critical to achieve ALMA full
A distributed network of ARC nodes (with ESO being the central ARC) has been set up throughout Europe at the
following seven locations: Bologna, Bonn-Cologne, Grenoble, Leiden, Manchester, Ondrejov, Onsala. These ARC nodes
are working together with the central node at ESO and provide both core and additional services to the ALMA user
This paper presents the European ARC, and how it operates in Europe to support the ALMA community. This model,
although complex in nature, is turning into a very successful one, providing a service to the scientific community that has
been so far highly appreciated. The ARC could become a reference support model in an age where very large
collaborations are required to build large facilities, and support is needed for geographically and culturally diverse
The Atacama Large Millimetre/submillimetre Array (ALMA) is one of the largest and most complicated observatories
ever built. Constructing and operating an observatory at high altitude (5000m) in a cost effective and safe manner, with
minimal effect on the environment creates interesting challenges. Since the array will have to adapt quickly to prevailing
weather conditions, ALMA will be operated exclusively in service mode.
By the time of full science operations, the fundamental ALMA data product shall be calibrated, deconvolved data cubes
and images, but raw data and data reduction software will be made available to users as well. User support is provided by
the ALMA Regional Centres (ARCs) located in Europe, North America and Japan. These ARCs constitute the interface
between the user community and the ALMA observatory in Chile.
For European users the European ARC is being set up as a cluster of nodes located throughout Europe, with the main
centre at the ESO Headquarters in Garching. The main centre serves as the access portal and in synergy with the
distributed network of ARC nodes, the main aim of the ARC is to optimize the ALMA science output and to fully exploit
this unique and powerful facility.
The aim of this article is to introduce the process of proposing for observing time, subsequent execution of the
observations, obtaining and processing of the data in the ALMA epoch. The complete end-to-end process of the ALMA
data flow from the proposal submission to the data delivery is described.