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 monthly 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.
The COVID-19 pandemic continues to impact the global community, including ALMA users and staff. While ALMA operations remain suspended, we have been working actively on plans to restart operations at a time that it is feasible. In these unprecedented circumstances, ALMA’s first priority is the health and safety of all our staff, many of whom travel long distances by bus and plane to reach the remote ALMA telescope site in the Atacama Desert of northern Chile. At this time, and given the current evolution of the COVID-19 outbreak in Chile, it is unclear when a ramp-up to start operations could begin, or when a restart of science operations will be possible. ALMA is working on guidelines and considerations for the restart of operations and will provide a next update to the community in the coming weeks.
In the meantime, Caretaker teams continue to maintain the safety of the ALMA equipment and infrastructure in both Santiago and in San Pedro, while all other staff continue to work remotely from their homes. The Regional ARCs continue to provide support to their communities. If you have any questions, comments or concerns related to the situation at ALMA, please contact the ALMA Helpdesk at https://help.almascience.org. This newsitem is also available on the ALMA Science Portal.
We are pleased to announce that approval has been given for the development of an upgraded ALMA Observing Tool (OT). This comes after the successful completion of a two-year study to investigate the feasibility of converting the OT to a web-based application. The current desktop tool began development nearly twenty years ago and so the upgrade will also bring it up to date in terms of the technologies used, bringing both user enhancements and easier maintainability. However, the core functionality of the OT will not change and it will continue to work with projects made with the current tool. Development will be based at the UK ATC in Edinburgh and is expected to last about three years.
A new development study, led by the Laboratoire d'Astrophysique de Bordeaux, will examine solutions to upgrade the ALMA digitization system. This study follows one of the key recommendations of the ALMA Development Roadmap, which is to increase the instantaneous bandwidth of the observatory by a factor of two or more. Importantly, the precursor study by the Bordeaux group identified a new digitizer that can cover an instantaneous bandwidth of up to 20 GHz per sideband. At the same time, these new devices would increase the quantization efficiency by more than 10%, increasing it to about 96 %, which would directly improve ALMA’s sensitivity. The performance of this digitizer will now be verified aiming at series production of around 100 devices. The study will also look into an upgrade of the optical transmission between antennas and correlator, which might in the future be located at the OSF building, as well as digital signal processing in order to cope with the higher data rates that will result from the upgrade.
The contract has been signed for the production of the final set of receivers to be installed on the Atacama Large Millimeter/submillimeter Array (ALMA). Of the originally foreseen ten receiver bands, eight have already been installed, and the ninth, Band 1, is currently in production in East-Asia. Now, contracts have been signed to start the production of the final band in the original ALMA definition — Band 2, led by ESO. Exceeding the originally defined frequency range for this Band (67-90 GHz), the proposed receiver will operate at the full 67-116 GHz frequency window. The hugely successful Band 3 receiver has already opened up the 84-116 GHz frequency range years ago, but the new Band 2 will allow for observations across the entire 67-116 GHz atmospheric window using a single receiver. The project will involve multiple international partners as detailed below.
ALMA data products have been integrated into the ESO Archive Science Portal along with data products from the La Silla Paranal Observatory (including APEX). Millions of datasets can be browsed jointly through a uniform set of query items, providing a unique integrated panchromatic view of the southern hemisphere extending from the near-ultraviolet to millimetre wavelengths. Queries can be carried out interactively through a web application which presents the results on the celestial sphere and provides aggregate and detailed individual information, or via direct database and Virtual Observatory access for programmatic, recurring and/or massive queries. The selected data can then be downloaded from the respective portals for ALMA and ESO. In this initial phase content from the ALMA Archive Interface is synchronised every two weeks, with the cadence progressively increasing with time.
The EU ARC has implemented a service which permits ALMA users to request the calibrated data for a given dataset (Member Obs Unit Set, MOUS) to be made available for download. 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.
ALMA is releasing data acquired as part of the Extension and Optimisation of Capabilities effort (EOC). These data were taken as part of the High-Frequency Long-Baseline Campaign (HF-LBC-2017) during Cycle 5, which was organised to test the calibration and imaging capability of ALMA at high-frequencies (>284GHz, Band 7) and using long baselines (>8.5km).
ALMA band 6 continuum observation of LkCA 15 from Facchini et al. (2020), accepted for publication in Astronomy & Astrophysics.
Transition disks are a particular class of protoplanetary disks, often hosting large cavities in their millimetre emission, and they are of prime interest to study the imprints of planet-disk interactions. Facchini et al. (2020) present ALMA high angular resolution observations of two of these objects revealing a remarkable level of substructure in the millimetre continuum emission, showing concentring rings and gaps outside the inner cavity. These rings are rather massive, hosting as much as 100 Earth masses in dust, and their physical conditions are ideal to form planetesimals. Hydrodynamical simulations show that these substructures can be induced by a Saturn-mass planet, which sculpts the morphology of the surrounding gas and dust densities. These planets, if confirmed, suggest that the outer regions of transition disks are favorable places for the formation of both planetesimals and planetary cores. These results are accepted for publication in Astronomy & Astrophysics.
The European ALMA Regional Centre (EU ARC) offers support to a large community of researchers hosted by European institutions. The support is offered to the ALMA user community through seven ARC Nodes and a Centre of Expertise which are spread across Europe, as well as the central ARC which is at ESO. The aim of this Special Session during the annual meeting of the European Astronomical Society is to bring together European ALMA users and the researchers providing support at the different EU ARC Nodes. This is a great opportunity for current and future users of ALMA to discuss new scientific results, observation and data reduction strategies, foster collaborations, and brainstorm on development and implementation of software from the user community. Additionally, it offers the opportunity to identify the need for new capabilities, some of which could be implemented in the near future, such as data combination from different array configurations, pipeline products delivery, and archive mining. More information can be found at the splinter session webpage. Registration to attend this special session is still possible.
YERAC 2020 conference postponed
Given the uncertainties due to the COVID-19 pandemic, and to avoid a late cancellation that would penalize the YERAC participants, the YERAC 2020 LOC/SOC has decided to postpone the conference until the summer of 2021. New dates will be announced early in 2021.
ALMA band 6 continuum observation of LkCA 15 from 
