Welcome to the European ALMA Regional Centre Newsletter!
This Newsletter, which appears on a monthly basis, is a compilation of recent European ALMA Regional Centre announcements. In addition to these, the Newsletter provides an inside look into ALMA operations, showcases some of the exciting science carried out with ALMA by our European colleagues, and informs you about ALMA or ALMA-related meetings.
On October 29, 2022, the Atacama Large Millimeter/submillimeter Array (ALMA) suffered a cyber-attack on its computer systems, forcing the suspension of astronomical observations and the public website. This event is under investigation by local authorities.The Computing team quickly isolated the Antennas and Correlator systems and the Science Archive data systems. However, communication and other operational clusters were affected, forcing ALMA to stop all observations. Since then, email communication has been restored safely, along with new collaboration tools that enable the staff to continue their regular work.
The Crisis Management Team has developed a full-recovery plan in consultation with cyber security officers from ESO/NAOJ/NRAO. Our highest priority is to work hard to resume observations before the end of the year.
CASA is the designated science data analysis package for ALMA. An updated reference paper on this software, which is produced jointly by NRAO, ESO, NAOJ, and JIV-ERIC under the guidance of NRAO, was published this month together with a sister paper on the new VLBI processing capabilities of CASA.
Allegro announces the 6th Netherlands ALMA Science Day, that will take place in person at Leiden Observatory on Thursday, 8 December 2022. At the Science Day, we will highlight the latest scientific results obtained with ALMA by the Netherlands astronomical community. The meeting will also allow ample time to discuss user experiences and other ALMA related topics. Registration for contributed talks is now open (registration form, deadline: 25 November 2022) and we welcome contributions in all science areas.
Following the 6th Netherlands ALMA Science Day, on Friday, 9 December Allegro will host an introductory ALMA Data Reduction Training also at Leiden Observatory. Allegro fellows will introduce CASA and ALMA data reduction techniques, share tips & tricks, and offer extensive hands-on training in data imaging and analysis. Students and postdocs are particularly welcome to attend the training, which will cover both basics and more advanced topics. The registration form will remain open until 2 December 2022.
Pavel joined the Czech ARC Node in 2011 and has been its manager since 2017. He has also been involved in contact scientist support, data quality assurance and testing of software tools. He has co-organized regular workshops for university students and local ALMA community, as well as ALMA-focused meetings (such as a special session at the EWASS 2017 conference). Pavel has been responsible for themodernization and upgrade of the HPC cluster at the Czech ARC nodethat is used for ALMA-related numerical simulations and data processing.
Pavel’s primary research interest is evolution of galaxies in galaxy clusters, especially jellyfish galaxies from which ram pressure of the intra-cluster medium strips cool interstellar matter and quenches their star formation. He has been leading the Cycle 8 Large Programme ALMA JELLY, which focuses on exploring the molecular content of a sample of nearby jellyfish galaxies with extended ionized and multiphase gas-stripped tails.
ALMA science highlight
Detection of the first Silicon- and Sulphur-bearing molecules in the Homunculus
The left panel shows the Eta Car and the Homunculus nebula in the infrared, as seen by the Very Large Telescope (adapted from Mehner et al. 2019). The inset shows the molecular ring in the equator of the Homunculus, as seen by ALMA, traced by CO (red), 13CO (green) and SiO (blue). The bottom panel shows the spectra of the newly detected molecules.
Eta Carinae is a very massive (~100 solar masses) star approaching the end of its life. Part of an eccentric binary system, this star has fascinated astronomers ever since the mid 19th century, when it underwent a gigantic outburst, dubbed the “Great Eruption”, that briefly made it one of the brightest stars in the night sky. This event expelled large amounts of gas and dust into the surrounding medium, forming the well-known Homunculus Nebula. The ejecta, rich in processed elements, is the perfect breeding ground for molecules, as attested by the prolific detection of many nitrogen-, oxygen- and carbon-bearing species in the last decade. Most of this molecular gas arises from a ring-like structure in the Homunculus’ waist, a dusty equatorial region known as “the butterfly” owing to its peculiar shape.
Recently, thanks to high-resolution ALMA observations, Bordiu et al. (2022) have found the first silicon- and sulphur-bearing molecules in the equatorial ring of the Homunculus: silicon monoxide (SiO), silicon monosulfide (SiS) and silicon mononitride (SiN). These molecules are distributed in clumps along the butterfly region, tracing the inner side of the ring (see Figure above). The detection of these species opens an exciting chapter in the study of the molecular ecosystem of Eta Car, providing direct evidence of the crucial role of shock induced chemistry. Molecules like SiO are created when dust grains are destroyed by the cyclical hammering of the stellar winds from the binary. These shocks, modulated by the ~5.5-year orbital period of the system, release the silicon trapped within the grain cores, which eventually adheres to free oxygen, sulphur or nitrogen atoms through diverse chemical networks, producing the aforementioned molecules. These findings thus yield valuable insights to understand the lifecycle of silicate dust in Eta Carinae, which in turn is crucial to explain the survival of molecules under its extreme conditions (high temperatures and intense UV fields). Besides, the observed abundances of SiO and SiS are unexpectedly low, more than ten timeslower than usually found in intermediate-mass stars (much cooler, and therefore more suitable for molecules). On the contrary, SiN, a rare molecule not so frequently found in space, is the most abundant of the three, reflecting the peculiar chemical composition of the Homunculus, rich in nitrogen.
In short, these detections confirm Eta Carinae as a unique laboratory to investigate the interaction between the winds of evolved stars and their surroundings; and shed new light on the role played by these dying massive stars in the productionof dust and molecules, which has important implications for the chemical enrichment of the early Universe.
The workshop will take place at the ESO Headquarters in Garching (Germany) from November 28 to 2 December, 2022
The formation and evolution of exoplanets can now be explored with instrumentation and observational techniques covering multiple physical scales and wavelengths. This workshop aims to provide an overview of the state of the field, to explore the synergies provided by ESO's current and future facilities (ALMA/ELT/VLT/VLTI/La Silla telescopes/CTA), and synergies with other space and ground-based observatories.The programme can be found here.
The third edition of the mm Universe conference series will be held at LPSC in Grenoble from 26th to 30th June 2023.
This international conference will bring together the scientific community working on science related to millimetre observations. It includes both theoretical and observational topics related to the mm Universe, from stellar to cosmological scales. As multi-wavelength analysis is a key approach to understand astrophysical processes and cosmological issues, the conferences series is of course opened to results and observations at other wavelengths.
To commemorate its first decade of science operations, the ALMA partnership is organizing a conference that will take a look back at the observatory accomplishments, highlight its latest results and look forward to future technical developments. The conference will be held in Puerto Varas, Chile on 4-8 December 2023. More information will be posted on the conference web page as it becomes available. Registration for the conference will open in early 2023.
