European ARC Newsletter
24 Nov 2020

Welcome to the European ALMA Regional Centre Newsletter!  

This Newsletter is a compilation of recent European ALMA Regional Centre Announcement items. The newsletter appears on a bimonthly basis. In addition to these Announcements the Newsletter provides an inside look into ALMA operations, showcases some of the exciting science carried out with ALMA by our European colleagues, as well as informs you about ALMA or ALMA-related meetings.

European ARC Announcements

2020 November Status of the ALMA recovery process

20 Nov 2020:

Dear colleagues,

With the COVID-19 pandemic continuing to impact our lives around the world, everyone at ALMA hopes that you and your families are staying safe and healthy. The pandemic situation in Chile is remaining stable and over the past few weeks ALMA staff have been moving forward with ALMA’s plan to recover the telescope array in the Atacama, as announced on October 1st, 2020.

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The First 60000 ARI-L Images are Now Available in the ALMA Science Archive

14 Nov 2020:

The first 60000 data cubes and continuum images generated by the Additional Representative Images for Legacy (ARI-L) ALMA development project are now available to download from the ALMA Science Archive (ASA). In addition to the primary-beam-corrected images, the released products also include the primary beams, and mask for all targets and calibrators of more than 1200 Cycle 3 and 4 datasets.

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New Helpdesk system Deskpro

13 Nov 2020:

On December 3 and 4 the ALMA Helpdesk will migrate to a new service provider, Deskpro. The new Helpdesk system will have the same functionality as the current system, but with a refreshed user experience for the ALMA user when creating tickets and interacting with the knowledgebase. We are confident that the new system will further improve the value of the Helpdesk in supporting exciting ALMA science!

Because of the migration to the new service provider the ALMA Helpdesk may be down during parts of December 3 and 4.

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Summary of ALMA 2020 UK Virtual Workshop

13 Nov 2020:

The UK ARC Node hosted its first virtual ALMA workshop for new postgraduate students during a series of half-days from the 9th to the 13th of November 2020.  This workshop covered the same topics that are featured in typical introductory ALMA workshops, including introductions to ALMA and interferometry, hands-on work with the Observing Tool and the ALMA Science Archive, and calibration and imaging in CASA. The difference was that this workshop was conducted entirely virtually, which presented some new challenges in terms of interactions with the participants, particularly in terms of troubleshooting problems. However, by the end, the participants succeeded in making their own ALMA images.

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I-TRAIN with the European ARC Network 

The European ARC Network is initiating I-TRAIN, a regular series of Interactive Training in Reduction and Analysis of INterferometric data. The sessions will cover a wide range of topics of interest to the ALMA user community with the aim to help users gain expertise in working with interferometric data.

The duration of each training session will be about one hour, including a live demo and interactive Q&A. Information on the I-TRAIN sessions and legacy materials will be available in the Science Portal.

I-TRAIN #1: Imaging with the ALMA Pipeline

23 Nov 2020:

The European ARC Network is offering an online training on the ALMA Science Pipeline on December 4, 2020, 11:00 CET [Zoom link]. In this training session participants will learn how to run the ALMA Science Pipeline for their own scientific purposes. They will be guided on how to tweak different parameters of the pipeline tasks to produce cleaned data cubes from publicly available ALMA data. This will allow users to obtain products that are tailored to the specific requirements of their science projects.


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I-TRAIN #2: ALMA Science Archive update and ARI-L

22 Nov 2020:

The European ARC Network is offering a topical training on some recently added functionality of the ALMA Science Archive like access to individual files, the CARTA remote visualization and the new ALMA VO services. The training session will be on December 15, 2020, 11:00 CET [Google link]. An overview over the European ALMA development project ARI-L will follow. ARI-L has already delivered over 74000 science FITS files to the ALMA Science Archive completing the existing ALMA products for Cycles 2-4.

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I-TRAIN #3: UVMultiFit

21 Nov 2020:

The European ARC Network is offering an online training on UVMultiFit on January 15, 2021, 11:00 CET [Zoom link]. The tool UVMultiFit is a versatile library for fitting models directly to visibility data. Visibility fitting can be a powerful method to analyze interferometric data and extract source information without the need to process image deconvolution. During this training session users will learn how to use this tool on real, publicly available ALMA data.

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Meet the ARC


Newcomers in the EU ARC Network

Dr. Violette Impellizzeri 

Violette is involved in ALMA since 2011, when she joined the Joint ALMA Observatory (JAO) in Chile. In 2014, she was hired as an operations astronomer taking on new tasks such as the Phase 2 Group (P2G) Lead, "friend of VLBI" and Proposal Handling Team (PHT) lead. On October 1, 2020 she joined the Allegro ARC Node in Leiden, taking on the role of Program Manager, and is very excited to be returning to Europe and connecting with the Allegro team and the ALMA scientific community in The Netherlands.

Dr. Ashley Bemis

Ashley is a first year postdoc in the Allegro group since November 1, 2020 and has been working with radio data since the beginning of her career. She is interested in the connection between dense gas and star formation in nearby galaxies and in the Milky Way. Her work employs gravoturbulent theories of star formation and the radiative transfer code RADEX to directly compare model predictions to observations of both gas and star formation. 

Dr. Katharina Immer

After her PhD at the University of Bonn, Katharina was a postdoctoral fellow in Karl Menten's group at MPIfR, and from 2014-2017 she was ESO Fellow in Garching. She has joined Allegro on November 15, 2020 as VLBI expert from the Joint Institute for VLBI-ERIC (JIVE), where she worked as support scientist for the past three years. 

Ana Karla Diaz Rodriguez

Ana Karla is a Doctoral Candidate at the Institute of Astrophysics of Andalusia, and the University of Granada, in Spain. She joined the UK ARC Node as support astronomer on October 1, 2020. Ana Karla has been working with radio interferometric data during her PhD, studying disks and jets in multiple young stellar systems. She is interested in how the standard view of isolated star formation changes in the presence of companions. She is currently taking her first steps in Machine Learning, with the goal of including it in her research.


ALMA science highlights

ALMA observations of the lensed quasar PKS1830-211,showing the main bright images A and B, with the third image C in between.

Gravitational lensing is a spectacular phenomenon and a powerful tool for astronomers. In the case of a perfect alignment between a source, a lens, and the observer, the resulting image of the source is a perfect Einstein ring. In less perfect alignments, a gravitational lens always produces an odd number of images, partially or well separated. One of them is always projected close to the center of the lens and, in contrast to other images, is highly de-magnified, by a factor 100 to 10000. Such an elusive weak image is therefore very difficult to detect, but brings important information on the lensing geometry of the system.

Thanks to the high angular resolution, sensitivity, and image dynamic range of ALMA, the third image of the radio quasar PKS1830-211 has now been unambiguously identified (Muller et al. 2020). The quasar, at a redshift of z=2.5, is strongly lensed by a galaxy at z=0.89 in its line of sight. The two bright images of the quasar (A and B on the figure) separated by only 1 arcsecond, have now a little sister in between them (image C), about one hundred times fainter.

These new observations shed light on the structure of the radio jet of the quasar (powered by a supermassive black hole), pinpoint the location and gravitational potential of the lensing galaxy, and tighten the measure of the Hubble constant, the expansion rate of the Universe at the present time.



Upcoming ALMA or ALMA-related Meetings

  • 4th Netherlands ALMA Virtual Science Day


Allegro announces the 4th Netherlands ALMA Science Day, which will be held (online) on Monday January 25, 2021. At this meeting, presentations will be given of the latest scientific results obtained with ALMA by the Netherlands astronomical community. Special guest speakers include Rychard Bouwens (Leiden Observatory, on the REBELS Large Program), Leen Decin (Leuven, on the Atomium Large Program - to be confirmed). The latest updates on the status of ALMA and its return to science operations will be also communicated, and there will be time reserved for discussing user experiences and other ALMA related topics. Registration including signing up for contributed talks is available here.

Following the Science Day, on Tuesday January 26 2021, introductory CASA training will be offered, again online. Throughout the remainder of that same week, Allegro staff will be available to (remotely) work with the users on exploring the capabilities of CASA on the Allegro computing system.

  • ALMA Early 2021 UK Virtual Workshop


By popular demand, the UK ARC Node is planning to offer a new ALMA Virtual Workshop in the Spring of 2021. This workshop, aimed at new ALMA users, will be a comprehensive overview of ALMA. The workshop will include an introduction to the observatory, a review of interferometry, a demonstration of using the Observing Tool for proposal preparation, an overview of using the ALMA Archive, and hands-on work with calibrating and imaging ALMA data.

People who are potentially interested in this workshop can express their interest as well as indicate their preferred dates for the workshop in the pre-registration poll. The workshop will be scheduled for either February or March 2021

  • Five years after HL Tau: a new era in planet formation

Our understanding of planet formation has been significantly challenged by recent observations during the last years. Recent high-resolution observations by ALMA and SPHERE/VLT have found compelling evidence of planet signatures much earlier than what was typically assumed, questioning the time at which planet formation takes place. This ESO/NRAO workshop aims to discuss the emerging new paradigm of planet formation. The program will offer a broad view of the field, covering from the early stages of disks still embedded in their parental envelope to the times when full planetary systems are formed and only a few remnants of the progenitor disk are left. The conference will take place virtually from 7 to 11 December 2020 (more information can be found here).