Doc 8.8, ver. 8.1 | March 2021

Guide to the European ALMA Regional
Centre

ALMA, an international astronomy facility, is a partnership of Europe, North America and East Asia
in cooperation with the Republic of Chile.

For further information or to comment on this document, please contact your regional Helpdesk through the ALMA Science
Portal at www.almascience.org. Helpdesk tickets will be directed to the appropriate ALMA Regional Centre at ESO,NAOJ or NRAO.

Version

Date

Editors

1.0

25 February 2011

Martin Zwaan

2.0

25 May 2012

Martin Zwaan, Evanthia Hatziminaoglou

3.0

14 October 2013

Martin Zwaan

3.1

23 July 2014

Martin Zwaan, Evanthia Hatziminaoglou

4.0

12 March 2015

Martin Zwaan, Evanthia Hatziminaoglou

4.1

29 November 2015

Martin Zwaan, Evanthia Hatziminaoglou, ARC nodes

5.2

16 March 2016

Martin Zwaan, Evanthia Hatziminaoglou, ARC nodes

6.0

20 March 2017

Martin Zwaan, Evanthia Hatziminaoglou, ARC nodes

7.0

March 2019

Martin Zwaan, Evanthia Hatziminaoglou, ARC nodes

8.0

March 2020

Martin Zwaan, Evanthia Hatziminaoglou, Gergö Popping, ARC nodes

8.1

March 2021

Martin Zwaan, Evanthia Hatziminaoglou, Gergö Popping, ARC nodes

Martin Zwaan, Evanthia Hatziminaoglou, Gergö Popping, the European ARC at ESO and the European ARC nodes.

In publications, please refer to this document as:
Martin Zwaan, Evanthia Hatziminaoglou, Gergö Popping 2021, Guide to the European ARC, ALMA Doc8.8
v8.1

Table of contents
Purpose of this document

2

ALMA in a nutshell

2

The ALMA Regional Centres (ARCs)

2

Organisation of the European ARC structure

2

Role of the central ARC and the ARC nodes

3

How the ARC can help with your ALMA observing project4

The ALMA Science Portal

4

The proposal stage

4

No preparation of Phase 2 Science Goals by the users

5

Tracking your project5

After data have been taken

5

The data reduction pipeline

6

Data reduction support

6

Calibrated measurement sets

6

Additional help from the European ARC

6Archive research support

6

Need training?

7

General questions

7

How to organise a face-to-face visit

7

Funding for visits

8

The ARC nodes

8

The Italian node in Bologna

8

The Dutch node in Leiden: Allegro

8

The German node in Bonn/Cologne

9

The IRAM node in Grenoble

9

The Nordic node in Onsala

10

The UK node in Manchester

10

The Czech node in Ondřejov

10

Historical contribution to the ARC network

11

The Portuguese Centre of Expertise in Lisbon: PACE

11

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Purpose of this document
The purpose of this document is to help users to find their way around the European ALMA Regional Centre(ARC). The European ARC is the 'one stop shop' for all European ALMA users. This document explains how the
ARC structure works and how it can help users at the various stages of their ALMA observing project.

ALMA in a nutshell
The Atacama Large Millimetre/sub-millimetre Array (ALMA) is the leading observatory at millimetre and submillimetre wavelengths and will be for many decades to come. ALMA is a global collaboration involving East Asia,
Europe, North America and the host country Chile. ALMA comprises 66 high-precision antennas equipped withreceiver and digital electronics systems to observe in the frequency range from 30 GHz to 1 THz and at angularresolutions down to 6 milliarcsec. Using a fully dynamic scheduling system and innovative calibration strategies,
the ALMA system allows observers to make the best use of the atmospheric conditions on the Chajnantor
plateau at 5000 m altitude in the Atacama desert. The European contribution to the ALMA project is led by ESO
on behalf of its member states.
ALMA has performed scientific observations since September 2011, in addition to regular commissioning andscience verification. Each observing period offers another opportunity for astronomers to propose science
projects with ALMA. Details on the new capabilities in this cycle are given in the Proposer’s Guide, available atthe ALMA Science Portal at http://almascience.org. More information on the ALMA project can also be found on
the Science Portal.

The ALMA Regional Centres (ARCs)
The interface between ALMA and the astronomical community is provided by the three partners through the
ALMA Regional Centres (ARCs). These are located at NAOJ in Mitaka, Japan, for the East Asian partnership, at
ESO in Garching, Germany, for the European partnership, and at NRAO in Charlottesville, USA, for the North
American partnership. The ARCs are staffed by scientists with expertise in radio astronomy, millimetre and submillimetre astronomy, and interferometry, and their purpose is to work with the community of astronomers tomaximise the scientific productivity of the telescope.

Organisation of the European ARC structure
The ARC structure in Europe supports the scientific use of ALMA by the European user community. The ARC
forms the interface between the ALMA observatory and the user community throughout the lifetime of a project,i.e., from proposal preparation to data analysis. In Europe, the services to the community are provided by a
distributed network of ARC nodes at Bologna, Bonn/Cologne, Grenoble, Leiden, Manchester, Ondřejov, andOnsala, under the coordination of the ESO ARC in Garching.
The primary aim of the European ARC is to maximise ALMA's scientific return for European users. Each ARC
node is staffed with scientists providing a range of experience in interferometry, (sub-)millimetre observing and
ALMA data reduction and interpretation, as well as a range in scientific interests. The staff at the ESO ARC andthe ARC nodes work together to provide optimal support to users during the complete lifetime of a project fromproposal preparation, validation of the Phase 2 material, delivery of the calibrated science products to the users,
and, if required, additional data reduction support, advice regarding observing strategies and they can help with
ALMA archival research. The ARC network organises community days, tutorials and workshops throughout
Europe to reach out to the community and to train users in proposal preparation and data reduction. Several
ARC nodes also supervise Master's and PhD students andgive university lectures on ALMA-related topics.
The central point of contact for current and prospective ALMA
users is the ALMA Helpdesk, which is available to all registeredusers from the ALMA Science Portal. There is one Helpdesk

For all ALMA questions: use the ALMA Helpdesk
to contact the ARC. The Helpdesk is available
through the ALMA Science Portal.

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for all ALMA users, but queries from European users will be primarily addressed by the European ARC, either byscientists in Garching or by staff in one of the ARC nodes. The Helpdesk includes a library of “Knowledgebase”
articles that address a number of common issues and questions. If the answer is not found in the suggested
Knowledgebase articles, the user can submit a ticket. During normal operations, users can expect a response
within two business days. During the week prior to a proposal deadline, extra staff will be assigned to theHelpdesk and every effort will be made to address time-critical questions in a rapid manner.

Role of the central ARC and the ARC nodes
The central ARC in Garching and the ARC nodes distributed throughout Europe work together to provide optimal
support to European ALMA users. It is however important to realise that the roles that the central ARC and thenodes fulfil are very different. For example, all face-to-face support, one of the core functions of the ALMA
project, takes place at the ARC nodes.
The different roles of the ARC and the ARC nodes are outlined below. Note that the typical ALMA user does notneed to know the specifics of how tasks are divided between the central ARC and the ARC network: All initial
contacts between the user and the ARC staff happen through the ALMA Helpdesk. The ARC staff may answer
the user's question immediately, refer to documentation, or forward the query to an expert within the ARC
network. The ARC may advise that face-to-face help is required, or the users may indicate themselves that theyneed to get in touch with their Contact Scientist (CS) or request face-to-face support.
The main tasks of the central ARC, of direct relevance to ALMA users, are:• Phase 1 operations: distribution of the call for proposals to prospective European ALMA users, user support
during proposal preparation as well as assistance in coordinating the proposal reviewing process.
• Manual generation and update of Scheduling Blocks when necessary, inspection of the automaticallygenerated Scheduling Blocks and implementation of changes following successful change requests.
• Data product support: quality assurance (QA2) of science data sets and delivery of the final raw and reduced
data to the PIs.
• Delivery of calibrated measurement sets.
• Staging of proprietary raw data deliveries.
• Archive operations: the ESO ARC node holds a complete synchronised copy of the ALMA archive.
• Running the ALMA Helpdesk.
The relevant tasks of the ARC nodes are:•Quality Assurance (QA2) of science data sets.

•

User support with proposal preparation by means of face-to-face meetings, dedicated workshops andthrough the ALMA Helpdesk.

•

Answering questions on technical details pertaining the scheduling and execution of the proposed
observations.

•Face-to-face help with data reduction, including expert support in data processing for specialised observing
techniques.

•

Help in archival research, including assistance to users of the ALMA archive in identifying and using the data
products suitable for their scientific projects.

•

Facilitate science coordination between ALMA users, i.e. providing space for small meetings, putting people
with similar interests in contact if mutually desired etc.

3•

Close interaction with the community and regular updates on ALMA (Community Days and other events,
newsletter, webpages), as well as community education through lectures, tutorials, and online material.

•

Outreach to the general public.

The following section describes in more detail the kind of support to be expected throughout the lifetime of an
ALMA project.

How the ARC can help with your ALMA observing project
For each scheduling period, a Call for Proposals for ALMA is issued. The ESO ARC distributes this call among
the European user community by email and makes it available on the ALMA Science Portal(http://almascience.org). The call provides information about the available capabilities for each cycle, necessary
information for the electronic submission of proposals as well as links to documentation such as the Proposer’s
Guide, the ALMA Technical Handbook and the Observing Tool (OT) User and Reference Manuals, as well as the
OT Quick Start Guide. For the complete list of documentation, see the relevant section on the ALMA Science
Portal.

The ALMA Science Portal
All ALMA users need to register to the ALMA Science Portal. ThisTo submit a proposal, download ALMA software,
is a single sign-on gateway to the various tools described below,
or gain access to the Helpdesk, you will need toregister with the ALMA Science Portal.
the Helpdesk, the ALMA Science Archive, and other relevant
information. Each astronomer who uses ALMA is assigned asingle ARC for user support at the time they register. ALMA users
should have one ALMA account, that they should update in case any of their profile details changes (e.g. e-mailaddress, affiliation etc). Users are furthermore expected to update their scientific expertise area, as thisinformation is used for the distributed peer review process.

The proposal stage
The Phase 1 material of the proposals must be prepared with the ALMA OT, available from the ALMA Science
Portal, section "Tools". The OT requires the users to provide a scientific and technical justification, target
specification, and sensitivity. The OT provides the users with
time-on-target plus overhead specification, integration time
estimation, transparency and atmospheric conditions, etc.
Use the ALMA Observing Tool to prepare yourproposal. Need help? Use the Helpdesk to

The ALMA Observing Support Tool (OST), hosted at the UK
contact the ARC.
node (http://almaost.jb.man.ac.uk/) provides an easy webbased interface to preparing simulations. The user can uploada FITS image and 'observe' it with ALMA at different frequencies, bandwidths, configurations, integration times
and weather conditions. The results are images as ALMA would produce them, together with point spreadfunctions and maps of the uv-coverage. This information can help users in planning their ALMA observations.
More experienced users may want to use simulation capabilities included in the CASA data reduction package,
which have more flexibility. For more details see http://casaguides.nrao.edu.
Staff at the European ARC network assist users with the
preparation of their Phase 1 material. This assistance covers
help with the OT, the ALMA exposure time calculator and thesimulator. Staff are also available for consultation regarding
observing strategies and the dual anonymous and distributed
peer review procedure.

Need help with proposal submission? Use theHelpdesk. Need face-to-face help for preparing acomplicated proposal? Use the Helpdesk tocoordinate a visit to an ARC node.

Users may also choose to visit an ARC node for face-to-face
support during proposal preparation.

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After the submission deadline, all proposals that request less than 25 hours on the 12-m array and/or less than
150 hours on the Atacama Compact Array (ACA) (corresponding to an ACA large progam) will go through the
distributed peer review process. Proposals requesting for more time on the 12 meter array or the ACA are
ranked by panels. A recommendation on the scheduling of ALMA projects for the coming period is made to the
ALMA director by the ALMA Proposal Review Committee (APRC) based on the outcome of the distributed
peer review process and the ranking by the panels.

No preparation of Phase 2 Science Goals by the users
Starting from Cycle 8 2021, PIs of accepted proposals will no longer have to submit their Phase 2 Science Goals.
In practice this means there is no longer a Phase 2 deadline and PIs are responsible for correctly providing allnecessary information when submitting the proposal to successfully schedule the requested observations. PIs
who are preparing a proposal and are unsure if they have listed all necessary information correctly areencouraged to get in contact with a node for support.
Immediately after the outcome of the proposal review process, the Scheduling Blocks (SBs) of accepted
programs will be automatically generated by the observatory and will be placed in the observing queue forscheduling and eventual execution. The Phase 2 team will make sure all SBs will run smoothly at the telescope(e.g. check calibrator variability, target proper motion). In case alterations to the program are needed, the user
can consult with the CS whether a change request should be submitted or if a small change can be implemented
by the Phase 2 team directly.
The SBs can be executed at any time without further intervention from users, CS or ARC staff. If a problem isfound at run-time, execution of the SB is halted. The Phase 2 team at the ESO ARC will fix the problem and theaffected SBs are put back in the queue for scheduling.

Tracking your project
The Snooping Project Interface (SnooPI) allows PIs, Co-Is andData Delegees to follow the status of their ALMA observing
projects. It allows the PIs to search for their active projects andget an overview of the SBs that have been observed, those in
the queue, those that are under processing, etc.

Follow project progress with SnooPI, which isavailable on the Science Portal under the"Observing’ menu.

After data have been taken
ALMA observing projects are dynamically scheduled, taking into account weather conditions, the configuration of
the array, the proposal ranking and possibly other constraints. Short projects may be observed within one day,whereas others may take several weeks or months to complete. After the observations for a project have been
completed, users are notified by email. Note that B- and C-rated projects will not be carried over to the next
cycle when not completed, while A-rated projects will automatically be carried over, for one cycle. Accepted
proposals under Director's Discretionary Time (DDT) will stay in the queue for the 365 days following theirapproval.
All data pass through a multi-tier quality assurance (QA) scheme before they are released to the user. ALMA data
sets can vary enormously in size depending on correlator settings, averaging times and total integration time.
Data size may range from tens of GB for the shortest observations to many TB for lengthy projects. Users candownload the data from the ALMA archive.
It is important to realise that all ALMA data are kept in the archive. All requests for data of any observing program
are handled through this archive. This ALMA Science Archive is accessible through the Science Portal.
PIs can request via the ALMA Helpdesk that QA0-pass raw data should be staged for download as soon as
they are available (i.e. before the full QA2 products are ready). The proprietary period for the entire Member
Observing Unit Set (MOUS) will start after the raw data from the first Execution Block (EB) in the MOUS havebeen made available to the PI. The release of raw data to the PIs will have no implications on the QA2 process.
The access of QA0-pass raw data replaces the previous stale data and early release of ToO and time critical5

data policies, but with immediate start of the clock for the proprietary time of the respective MOUS the raw
data belongs to.

The data reduction pipeline
When a block of data for a particular program has been
observed, the ALMA data reduction pipeline is activated. This
pipeline runs on dedicated machines in Chile and in the ARCs
and it uses a heuristics system to automatically edit, calibrate,and image data. The pipeline heuristics have captured theknowledge of experienced radio interferometer users andincorporated it into the reduction scheme. The output of thedata reduction pipeline is stored in the ALMA Science Archiveand is subject to a final QA2 before the reduced data aremade available to the user.

Pipeline calibration has been fully commissioned
for most observing modes employed in previous
cycles but about 15% of observing projects will
still be calibrated manually using standard scripts(e.g., high frequency bands, full polarisation). The
data processing will be done using a combinationof the pipeline and manual analysis using CASA.

Data reduction support
The data reduction pipeline produces high quality science products. Expert hands-on help with data reduction
may be required however, especially when more complicated observing techniques are used. The ARC is theprimary contact point for users who need assistance with data reduction. ARC staff provides basic data analysis
support, ranging from simple advice, to providing appropriate data analysis documents and products, to detailed
assistance for users who require it.
The primary responsibility of the ESO ARC is to ensure that
Basic data reduction support: use the Helpdesk.
the reduced data from all ALMA observing modes meet theAdvanced data reduction support: visit an ARC
requirements set by the approved observing proposal. The
node (use the Helpdesk to coordinate a visit).
ARC nodes can provide further assistance to users who
require it. A likely scenario may be the following: the ALMA
data reduction pipeline has processed a user’s data set. If thedata meet the requirements defined in the proposal, the data are delivered to the user. However, the user may
wish to make images with higher spatial resolution or higher sensitivity. The ARC nodes can help to reprocess
the data, using different weighting schemes in the imaging stage. Another user may need higher dynamic range
image cubes and can work with an ARC node to apply self-calibration to the data. For the use of nonstandard
analysis techniques and the utilisation of the advanced algorithms and software developed by a specific ARC
node, ALMA users may also arrange a visit to this ARC node, where the best possible support can be provided.
The ARC nodes provide the latest (or any relevant) version of CASA, installed on high performance workstations
with ample disk space. For any first line CASA support, please visit the CASA Guides website at
http://casaguides.nrao.edu.

Calibrated measurement sets

Calibrated measurement sets can be requested

through the Helpdesk. More information is given
Scientists have the opportunity to request calibrated dataat this link.
products. These requests are done through the ALMA
Helpdesk: select Archive and Data Retrieval department
followed by the "Data request" sub-category. Per ticket,
scientist can request the calibrated data for up to 10 datasets (MOUSs), after which scientists in the ARC willstage the calibrated data products for download for a period of 28 days. The service is open both for ALMA PIs
or Delegees with proprietary ALMA data and for archival users wanting to use datasets for which the proprietary
time has expired. More information is provided at this link.

Additional help from the European ARC
Archive research support
A complete, synchronised mirror of the ALMA archive is kept at ESO and is a valuable resource for data mining.
Assistance for archive research encourages broader approaches to scientific investigations. Therefore, scientists

6

in the ARCs and ARC nodes offer support for astronomers
accessing the ALMA science archive. The ALMA Science
Archive is available through the User Portal.

Basic archive research support: use the Helpdesk.
Advanced archive exploitation support: visit an
ARC node (use the Helpdesk to coordinate a visit).

Prospective ALMA users are likely to want to consult theArchive when planning observations as well as for data mining.
To ensure that the archive (and ALMA) is exploited to its fullpotential, ARC network staff can assist users in using the archive. This includes face-to-face visits. Note that only
PIs and Data Delegees can access projects completed within the last 12 months.
The ARC network can also help users extract information effectively (such as potential calibration source
properties, or whether there are public domain data matching the required criteria) as well as assist with analysisof archive data.
Users can inspect data in the archive directly from their browser using CARTA (Cube Analysis and Rendering
Tool for Astronomy), a next generation image visualization and analysis tool designed among others for ALMA.
CARTA was introduced as a new development in the ALMA science archive in 2020. All image products ingested
into the archive are directly accessible for investigation with CARTA through the ALMA request handler.

Need training?
The European ARC regularly organises workshops,
tutorials and schools related to ALMA. Dedicated CASA
Need information on upcoming ALMA related tutorials
data reduction tutorials are held throughout Europe, as
and workshops? Check the European ARC
well as sessions describing the ALMA OT and moreannouncements or subscribe to the mailing list of yourgeneral workshops explaining the current ALMA
local ARC node.
capabilities. Additionally, the European ARC Network
offers online video tutorials and training sessions suchas the regular series of Interactive Training in Reduction
and Analysis of Interferometric data (I-TRAIN). The European ALMA newsletter and announcements provide a listof all scheduled activities and the mailing lists of the ESO ARC and the local nodes are used to disseminate thisinformation.

General questions
For any general questions related to ALMA capabilities,
availability of observing modes, or other relevant topics, please
use the Helpdesk.

Any questions related to ALMA: use the Helpdesk

How to organise a face-to-face visit
The preferred way to obtaining any type of support is through the ALMA Helpdesk: select “Submit a Ticket”, then“Face to Face Support (EU)”. In the Helpdesk ticket and in order to make the most of the face-to-face visit theuser should give as much information as possible on the purpose of the visit and the proposed node and dates.
Support staff at this node are responsible for arranging the details of the visit. Each visitor is assigned a
dedicated member of staff for support purposes and can expect that this support person will be able to respondas quickly as possible to their requests for help, within reason.
Depending on the exact request for support, users either visit their local ARC node or the node that has the best
specialist knowledge to support the user (to be determined by the user and the ARC (node) staff). Users canrequest a face-to-face visit regardless of the existence of a local node.
ALMA data reduction will normally be performed using dedicatedcomputing facilities such as those provided by the ARC nodes.
The data volumes are too large for laptops in most cases, except

To organise a face-to-face visit: use the Helpdesk

7

for the later stages of image or spectral analysis, possibly using subsets of the data. Please consult ARC staff if
you want to use your laptop.
To ensure data are downloaded locally and ready for the PI, the PI must give explicit permission for processed
and raw data to be downloaded from the ALMA Science Archive by the ARC node staff via the “Projectdelegation” tab in their ALMA Science Portal User Profile. ARC nodes provide facilities for the user to copy data
onto a hard disk drive. Data backup should be discussed prior to the visit, so that the user can bring appropriate
storage devices. Some nodes can also support ftp of data provided the link at the user's home institute is fastenough.
ARC nodes keep a copy of the data the user has been working on for at least a few weeks after the end of theuser's visit. This enables the node staff to address any post-visit questions which may arise.
After a visit, the user is requested to submit a feedback form on the service received, indicating, among otherthings, whether the goals of the visit were met.

Funding for visits
It is foreseen that most users will apply for funding from their local agencies for travel to one of the nodes in the
ARC network. Some ARC nodes have access to funds for visiting scientists. Please check the details in the next
section or visit the ARC node web pages.

The ARC nodes
Each node has its own area(s) of expertise. Users are encouraged to visit the individual ARC node web pages toobtain the most up-to-date information. Most ARC nodes also maintain email lists that are used to inform theirlocal communities about activities and region-specific news items.

The Italian node in Bologna

Visit the Italian ARC node at
http://arc.ia2.inaf.it/

The Italian ARC is hosted by the INAF-Istituto di Radioastronomia in Bologna.
Support is offered with proposal preparation and submission, tracking of
accepted ALMA projects, data reduction with CASA, and with ALMA archive mining, polarimetry and mm-VLBI
with ALMA, our three areas of expertise.

The Italian ARC also investigates new techniques of data reduction and handling and is heavily involved in thedevelopment of the ALMA science data archive. It organizes seminars, tutorials and workshops to inform andtrain the Italian community and to stimulate scientific discussion and collaborations. ARC personnel are involvedin teaching and supervising students.
Multi-wavelength research, especially through the use of archives, is becoming more and more requested. The
Italian ARC therefore also offers assistance with reduction and analysis of data taken with other interferometers.
The Italian ARC researchers are involved in several (sub-)millimetre scientific projects covering different topics(from galactic and local-Universe studies to high-redshift galaxies and cosmology), and offer general scientificsupport on their specific area of expertise for continuum and spectroscopic observations.
At the host institute, the ARC node can accommodate visitors for face-to-face support and visits. Visitors canconnect to a dedicated computer server, to access the data and run the CASA data reduction software.
The ARC node is connected to the outside world through a high-speed optical fibre network, allowing fast datatransfer (10 Gbit/sec). Outside users of ALMA and CASA can access the ARC node cluster facilities for a certain
period of time.
No local funding is available for visitors.

The Dutch node in Leiden: Allegro
Allegro, the ARC node in the Netherlands, is located at Leiden Observatory. The
node employs approximately six postdocs and staff members who coordinate thenode's activities. Allegro provides general user support for the ALMA community

Visit the Dutch ARC node atwww.alma-allegro.nl

8and offers expert help on high-frequency and long-baseline ALMA observations, mm-VLBI observations,and science analysis tools.
The Allegro node supports users in all the steps, from ALMA proposal preparation through data delivery and data
analysis. We offer assistance tailored to the needs of the user and organise activities for our user community.
Allegro has guest desks available for visitors, who can make use of the dedicated high-performance computing
facilities and connected fast-access storage system.
Allegro also contributes to the progress of the field within its own expertise areas. The node hosts expert
knowledge in high-frequency and long-baseline observations with ALMA. By investigating techniques toovercome the impact of atmospheric effects, such as water vapour fluctuations, we drive ALMA towards
reaching its full potential at the highest possible resolution and frequencies. The team has also partnered with the
mm-VLBI group at Radboud University to develop Very Long Baseline Interferometry with ALMA, offered since
Cycle 4 with the Global Millimetre VLBI Array (3mm) and the Event Horizon Telescope (1mm). In addition, Allegro
develops science analysis tools, like ARTIST/LIME, to assist scientists in the analysis and interpretation of theirobservations.

The German node in Bonn/Cologne
The German ARC node is a collaboration between the astronomical institutes at
Visit the German ARC node at
the universities of Bonn and Cologne. The node's main facilities are located at
astro.uni-bonn.de/ARC
the Argelander-Institut für Astronomie in Bonn, right next to the Max-PlanckInstitut für Radioastronomie and a 30-minute commute from the University of
Cologne. A number of staff members and postdocs are associated with the ARC node, working on various
support tasks. Areas of special expertise include the combination of interferometric data with single-dish data as
well as advanced analysis and modelling of spectral line data. The node maintains and continuously extends the
Cologne Database for Molecular Spectroscopy and offers a number of data analysis tools developed in-house. In
close collaboration with the mm-VLBI group of the Max-Planck-Institut für Radioastronomie, the node also
supports the use of ALMA in global mm-VLBI networks.
Visitors to the German ARC node can use the spacious ARC visitors' room equipped with workstations, switches
for laptops and a conference phone, and a parent-child office, located next to the ARC visitors' room. The
workstations offer fast connections to two high-performance servers dedicated to ALMA-related work. The
servers run all the latest ALMA software necessary for the proposal stage, data reduction and analysis and for
ALMA archive searches. Up to two visitors can be accommodated simultaneously.
In addition to user support, development and services to ALMA operations, the German ARC node reaches out
to the local community with annual community meetings, a local newsletter and talks at seminars andconferences. The node's regular training opportunities include (remote) participation in two comprehensive
hands-on lecture series on radio interferometry and radio astronomy in general, a CASA tutorial and ALMA-OT
tutorials. In addition, some members of the ARC node participate actively in general public outreach and teacher
education.

The IRAM node in Grenoble
IRAM (Institut de Radio-Astronomie Millimétrique) is an international institutesupported by the Max Planck Society (Germany), the CNRS (France), and the IGN(Spain). The institute operates the 30-m Pico-Veleta antenna and the NOEMA mminterferometer.

Visit the IRAM ARC node atwww.iram.fr/IRAMFR/ARC

The IRAM ARC node activities are built on the in-house experience with user support and on the involvement of
the institute in the ALMA design and construction phases (e.g. the development of the ALMA real-time Telescope
Calibration software). The face-to-face support for ALMA uses the same procedures and infrastructures as thoseused for the NOEMA support. A computer room dedicated to data reduction is available and each project is
assigned to a local contact. The ARC node involves 4 core members (3 staff and 1 postdoc), with additional help
from other IRAM staff. The IRAM ARC node provides a good opportunity to use synergies between the IRAM
instruments and ALMA, as, e.g. an access to the full sky for interferometric observations or to large-scale surveys
with the 30-m antenna.

9

Funding is available for travel and accommodation, with the usual IRAM rules: one mission/one person per
project. Funding is however limited to astronomers affiliated to one of the IRAM funding agencies.

The Nordic node in Onsala
Visit the Nordic ARC node at
The main mission of the Nordic ARC node is to provide full support for ALMA
www.oso.nordic-alma.seusers in Sweden and other Nordic and Baltic countries. The Nordic node
employs experienced millimetre wave observers and IT support. The node isphysically located at Onsala Space Observatory (OSO) near Gothenburg,
Sweden. OSO is the Swedish National facility for Radio Astronomy and is hosted by Chalmers
University of Technology. OSO has a long history in millimetre/sub-millimetre astronomy and presently runs the
20-m single dish telescope at Onsala and is a partner in the APEX sub- millimetre single dish telescope at the
ALMA site in Chile.

Nordic ARC services include e.g. face-to-face support for ALMA proposal preparation, project follow-up, data
reduction and analysis as well as access to archives. The node has expertise in the areas of astrometry, selfcalibration, multi-frequency synthesis, deconvolution algorithms, visibility fitting and polarisation. The node also
maintains several advanced data analysis packages. In collaboration with academic staff at Chalmers, there isalso extensive scientific expertise on-site in the areas of radiative transfer and astrochemistry. The Nordic node isalso active in community outreach and organises meetings and training events for the whole Nordic community.
The ARC node has high capacity data links for downloading archival data and high performance computer
facilities to support ALMA data reduction. The node offers flexible face-to-face support in any combination of onsite visits and remote support. There is ample dormitory and guest room accommodation on-site to support data
reduction visits and small workshops. No local funding for travel and accommodation is available.

The UK node in Manchester
The UK ARC Node is centrally located at the University of Manchester, Jodrell Bank
Visit the UK ARC node atCentre for Astrophysics, conveniently placed for all national and international
http://www.alma.ac.uk
transport links and high-speed internet connectivity. Five ARC staff (plus IT andadministrative support) divide their time between face-to-face user support andrelated research and development. Facilities for visiting astronomers include a large, dedicated room with ample
desk space and powerful computers, which can also be used for small meetings and tutorials. Absolutebeginners or experts are welcome and resources can be made available by arrangement for teams working on
ALMA projects with demanding computational and skills requirements.
The UK ARC Node draws on local and national expertise to offer specialised assistance in a number of areas:• Interferometry skills, in particular advanced calibration, extended array configurations (high resolution), wideband high-sensitivity continuum imaging (multi-frequency synthesis), mosaicing and wide-field imaging(including combining ALMA configurations to improve image fidelity), and polarimetry.
• Multi-instrument research, in particular comparing data from different telescopes, (e.g. Herschel, JCMT, eMERLIN, EVN) combining ALMA and compatible data, and interoperability between CASA and AIPS. The UK
ARC Node is part of the JBCA Interferometry Centre of Excellence which provides support for these
instruments, others such as LOFAR and prospective SKA users.
• Data management, in particular data mining the ALMA Archive, development of pipelines and scripts for large
projects, standards and documentation for data publication.
• Simulations using the OST (http://almaost.jb.man.ac.uk/) or inside CASA: choosing suitable input images,
estimating the brightness on ALMA scales and so on.
• No local funding for travel and accommodation is available

10The Czech node in Ondřejov
The Czech node is located at Ondřejov observatory near Prague, well accessible
Visit the Czech ARC node atby public transport, hosted by the Astronomical Institute of the Czech Academy
www.asu.cas.cz/almaof Sciences. The node’s mission is to provide support to ALMA users namelyfrom the central and eastern regions of Europe, but due to its exclusive expertisein solar observations to all European users. The node's duties are distributed over two staff members and four
postdocs, plus IT and administrative support.
The team is ready to provide (face-to-face) support with preparation and submission of proposals to ALMA andother (sub-)mm and radio telescopes, with data processing, interpretation of observations and numericalmodelling of some observed processes. A dedicated office equipped with personal workstations and access to a
HPC computer cluster is available for up to three visitors. Accommodation in the guest rooms of the
Astronomical Institute at Ondřejov can be offered. Visits at the Prague department of the Astronomical Institutecan also be managed.
The expertise areas of the Czech node are:
• Solar ALMA observing mode: specifics of proposal preparation, calibration and imaging; solar radio
spectroscopy; non-LTE radiative transfer; physics of the solar chromosphere, prominences and filaments; solar
flare plasma astrophysics.
• Galaxy evolution in clusters and groups, triggered star formation, proto-planetary disks, Galactic Centre and
AGN.
• High-resolution microwave laboratory spectroscopy of small molecules, in collaboration with the University ofChemistry and Technology in Prague.
Visitors can apply for a local support for travel and accommodation.

Historical contribution to the ARC network
The Portuguese Centre of Expertise in Lisbon: PACE
The Portuguese ALMA Centre of Expertise (PACE) was part of the ARC network from 2014 till 2021 and washosted by the Institute of Astrophysics and Space Sciences, located at the Astronomical Observatory of Lisbon.
During the collaboration with the ARC network, a team of astronomers from PACE developed expertise ininterferometry at mm and radio wavelengths. In particular, PACE astronomers are now experts in the calibrationand imaging of ALMA data and exploiting the ALMA archive for science. Building upon this expertise, PACE
astronomers successfully contributed to the quality assurance of ALMA data (12 meter and ACA) and frequently
participated in the testing of ALMA software and in the organisation of international workshops. To further
support the national community with their ALMA science, PACE astronomers organized community events,
provided face-to-face user support, support with the preparation of ALMA proposals, as well as support witharchival research. PACE furthermore supported the creation of new graduate and post-graduate level radioastronomy courses and maintained a strong outreach team through which it educated the national community
on mm-to-radio astronomy.

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