European ARC Newsletter
23 Feb 2023

Welcome to the European ALMA Regional Centre Newsletter!  

This monthly newsletter is a compilation of recent European ALMA Regional Centre news and announcements and showcases an exciting ALMA science result by European colleagues. In the "Meet the ARC" section, the work of ARC personnel and the services and expertise areas of an ARC node are highlighted. Every month, you can learn an incredible ALMA fact in "Did you know" and give your opinion about a particlar ALMA matter in the "Poll of the month". Upcoming ALMA and ALMA-related meetings as well as an entertaining social media post of the past month are highlighted at the end of the newsletter.

News and announcements Science highlight Meet the ARC
Poll of the month Did you know ALMA (related) meetings Social media highlight


EU ARC - ALMA drawing competition! 

In honour of 10 years of ALMA, the EU ARC social media team is organising a drawing/painting competition for the young and the young at heart! For the chance to win one of our prizes, you'll need to get creative: draw or paint an ALMA-related picture and post it in the comments of one of the related posts on our Facebook, Instagram or Twitter accounts! Anything goes, as long as it's in some way related to ALMA (you may want to add a comment to that effect if it is not obvious!). The deadline for submissions is the 13th of March 2023 - ALMA's tenth birthday!

Compilation of ALMA and ALMA-related images

Inspirational compilation of ALMA and ALMA-related images


ALMA science highlight

ALMA resolves the molecular clouds of a strongly lensed Milky Way progenitor observed at z=1

HST image and ALMA CO(4-3) observations of A521-sys1
The left panel shows the HST RGB-colour composite image of the strongly lensed A521-sys1 galaxy at z=1 together with the foreground Abell 521 galaxy cluster members (black crosses). The critical line of the lens model is shown by the red solid line. The entire A521-sys1 galaxy can be seen in the north-east uniformly lensed image, while the 11 arcsec-long arc, where one reaches the higher magnification factors, provides a zoom-in on the western spiral arm of the galaxy. The overlaid white contours correspond to the ALMA CO(4-3) velocity-integrated intensity in levels of 4, 5, 6, 7, 8, 10, 12, and 14σ. The ALMA synthesized beam with a size of 0.19" x 0.16" is represented by the white ellipse. The right panel shows examples of the integrated CO(4-3) emission line spectra, together with their best Gaussian fits in red, of three molecular clouds among the 14 that were detected in A521-sys1.

Star clusters are formed via the condensation of molecular clouds, which are made out of cold and dense gas and are found in all galaxies. While UV-bright and massive star cluster complexes are ubiquitously observed in galaxies at the peak of the cosmic star formation rate density, located more than 8 billion light-years away, the molecular clouds that gave birth to these clusters remained undetected so far. ALMA has recently confirmed the presence of these molecular clouds in a Milky Way in the making, the A521-sys1 galaxy at redshift 1. Galaxy cluster Abell 521 acts as a natural telescope, magnifying and enlarging the size of A521-sys1. Observations with the ALMA interferometer, at an angular resolution of 0.15 arcseconds, made it possible to resolve the molecular clouds in A521-sys1 individually down to 30 parsecs.

These superb ALMA observations of the CO(4-3) spectral line emission, used as the tracer of the cold molecular gas, enabled Dessauges-Zavadsky et al. (2023) to reveal that the molecular clouds of distant galaxies have a mass, density and internal turbulence 10 to 100 times higher than the clouds of nearby galaxies. The authors attributed these differences to the ambient interstellar conditions of distant galaxies, which are too extreme for the survival of the molecular clouds typical of nearby galaxies. Yet this galaxy is "normal" for its epoch and does not host a starburst. They also suggested that these distant molecular clouds appear to form a fairly high fraction (about 30%) of their mass in stars, a particularly high efficiency of star formation with respect to less than 5% observed in nearby galaxies, likely triggered by the highly supersonic internal turbulence of the clouds.

These results highlight the capabilities of ALMA to investigate the small-scale structure of the molecular gas in the interstellar medium of high-redshift galaxies, and hence open the perspective to analyze the star formation process across cosmic time at molecular cloud scale. Specifically, ALMA in synergy with JWST observations will allow to confirm and understand the ability of molecular clouds in distant galaxies to form stars so efficiently. 


Meet the ARC

Photo of Elisabetta Liuzzo

Dr. Elisabetta Liuzzo

Elisabetta joined the Italian ARC Node in 2013 where she is involved in different activities. She provides user support for archive mining, proposal preparation and advanced data analysis. She is co-organizing regular ALMA-related training events for the local community. Recently, she is involved in the EU ARC network effort to improve the user experience in the full scientific exploitation of ALMA data and expertise. In this framework, she is contributing to the organization of workshops, such as MAYA.

Elisabetta's main research interest is the study of the jets in Active Galactic Nuclei at high angular resolution using Very Long Baseline Interferometric observations in the radio and millimeter band. She is member of the Event Horizon Telescope Collaboration with role as European Board guest member and involvement in the Calibration and Errors Working Group for the data calibration and imaging with CASA pipeline. 

Photo of Peter Schilke

Prof. Dr. Peter Schilke

Peter is leading the Cologne branch of the German ARC node since its inception, where he is mostly active in management. His science interests are centered on high-mass star formation and astrochemistry, but he is also studying the diffuse interstellar medium. Since observations of high-mass star forming regions often involve very complex and crowded spectra, he developed the XCLASS package to deal with fitting many-line spectra to derive their physical parameters. During the ARC node period, this package has been ported to python to be interoperable with ALMA data, and its functionality has been significantly extended. This endeavor is helped by the close proximity of the Cologne Database for Molecular Spectroscopy at the University of Cologne. Peter is co-PI of the large ALMA program ALMAGAL, which has gathered experience with processing the large data sets with supercomputers.

Allegro node

Group photo of the Allegro ARC node

Allegro is the European ARC node in the Netherlands based at Leiden Observatory. Allegro supports the ALMA communities in the Netherlands as well as other European users. The Allegro team consists of five postdocs, two staff astronomers and IT support, and their main activities fall into user support and expertise development. User support  includes contact scientist duties, face-to-face visits, workshop preparations (e.g., proposal preparation workshops or CASA trainings) as well as providing computing resources to all Allegro users for the storage and processing of ALMA data. The team organises a yearly ALMA Science Day with the aim of bringing together its community, sharing results and exchanging ideas. Allegro is an active member of the EU ARC node, contributing to the I-TRAIN series (as lecturers and organisers), to the organisation of the MAYA meeting (next meeting is in March!) and many more schools/activities organised by the ARC.

The Allegro expertise areas include high frequency observations, ALMA-VLBI and archival research. A substantial fraction of the efforts of the Allegro team goes into expertise work. Some recent highlights include a phase metrics study (an official ESO study, co-led by Luke Maud and Andres Pérez-Sánchez) to characterise the phase stability at the ALMA observatory over the past observing cycles, the development of a pipeline for ALMA-VLBI QA2 and support of VLBI projects (Katharina Immer, Ciriaco Goddi), a study of the outliers in the ALMA calibrator's database (Alex Hygate), the development of a Python-based code to query, analyse, and visualize the ALMA Archive (ALMiner, Aida Ahmadi, Alvaro Hacar), and the study of a high frequency flux density calibration scheme using the SEFD (Ashley Bemis). This is a non-extensive list of some of the projects that are currently carried out and allow Allegro to be well embedded within the ALMA network and its community.

Last but not least, Allegro is devoted to science communication and outreach. In the frame of the 2022 Leiden City of Science program, Allegro launched a city tour called ALMAxLeiden. The tour was inspired by the notion that Leiden is as big as the longest ALMA configuration (~ 16 km). The tour can be accessed via a website or phone application: and starts at Leiden's Old Observatory. Tour participants explore secret alleys and landmarks of this beautiful medieval city while learning more about the ALMA Observatory and general interferometry. ALMAxLeiden was developed by the Allegro team and won the 2022 Royal Holland Society of Science Outreach Award. So, come and visit us in Leiden -- or stay tuned, because ALMAx... may come to your city soon!

ALMA poll of the month


How do you rate your level of ALMA expertise?




ALMA poll results January 2023





Did you know...

that there are two different ways to display the weblog? You can either use the task h_weblog() within a local CASA session or a python3 call without a CASA session to create an http server in which the weblog can be viewed. Detailed instructions can be found in this knowledge base article.


Upcoming ALMA or ALMA-related Meetings

Supernova 1987A

Special Session at EAS 2023: "The millimeter transient sky: present opportunities and perspectives"

During the European Astronomical Society Annual Meeting that will take place in July 2023, a Special Session will be held with focus on transients and time-variable objects at mm wavelengths. Following the advent of ALMA, with unprecedented sensitivity, and upgrades of existent mm observatories, observations and monitoring of variable objects like X-ray binaries, Gamma-Ray Bursts, Supernovae, Tidal Disruption Events, Protostars or Blazars at the short variability timescales needed for these objects are now a reality. The session will showcase the advancements in the field over the past years and discuss how to overcome the challenges of time-domain observations, in particular in view of upcoming mm facilities like CMB-S4, which will allow daily discoveries of mm transients to be followed up by other facilities, or the ngEHT.

Abstract submission is now open at, with a deadline on the 1st of March 2023.

National Radio Science Conference

40th National Radio Science Conference

We are pleased to invite you to submit your original research papers to the NRSC2023 ( The conference will be held in Smart Village, Giza, Egypt in the Arab Academy of Science and Technology from 30th of May to 1st of June. Accepted papers will be published in the conference proceedings conditionally upon presenting it at the conference venue. Presented papers will be considered for inclusion in IEEE Xplore. Special student sessions will host a limited number of posters presenting their graduation projects or post-graduate theses without registration fees. The award committee will grant awards to the most prestigious papers. Extended versions of awarded papers will be invited to be published in the URSI Radio Science Bulletin. Paper submission deadline is 24th of March 2023.


Social media highlight

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