Welcome to the European ALMA Regional Centre Newsletter!
This monthly newsletter is a compilation of recent European ALMA Regional Centre news and announcements, showcasing an exciting ALMA science result by European colleagues. Every month, you can learn an interesting ALMA fact in "Did you know" and give your opinion about a particular ALMA matter in the "Poll of the month".
ALMA Cycle 12 Call for Proposals for scientific observations is now OPEN!
ALMA Cycle 12 is currently scheduled for observations from October 2025 to September 2026. Users of any nationality or affiliation are invited to submit proposals before the deadline of 15:00 UT on Thursday 24 April 2025.
The European ALMA Regional Centre (ARC) network is organizing virtual and in-person proposal preparation events related to the Cycle 12 Call for Proposals across Europe. A complete overview of the activities and information about participating can be found here.
The Czech ALMA Regional Centre node is organising a workshop aimed to prepare the local communities for the upcoming ALMA Cycle 12. The focus will be on the preparation of observations, capabilities of ALMA in Cycle 12, important observation parameters, examples of observing proposals, work with the Observing Tool application for the preparation and submission of proposals, etc.
ALMA is exploring key upgrades to enhance its sensitivity, resolution, and imaging capabilities, focusing on transformative advancements that will unlock its full scientific potential. As part of an ongoing ESO ALMA development study aimed at advancing ALMA's capabilities, the community workshop "Unlocking ALMA's Potential with Focal Plane Arrays" will take place on September 2 - 4, 2025, at MPIfR, Bonn.This event will explore the scientific drivers and technological innovations behind focal plane arrays (FPAs) - a breakthrough that could significantly expand ALMA's field of view and mapping speed
A grand-design spiral galaxy with an ordered magnetic field 11 billion years ago
Left: the image-plane configuration of HERS1 showing the gravitationally lensed dust continuum at 50 milliarcsecond resolution with ALMA (green), Stokes I from the polarised ALMA dataset (blue) and polarisation vectors (black arrows). The background image shows the two foreground lensing galaxies in HST/WFC3 F125W. The beams are shown in the bottom left corner. Right: the recovered source plane dust continuum morphology (colour map) and magnetic field orientation (black arrows).
Magnetic fields are thought to originate from weak seed fields present in the early Universe, but it is unclear how they evolve into the well-ordered structures observed in nearby galaxies today. A favoured scenario is that small-scale fluctuation dynamos efficiently amplify magnetic fields to near equipartition strength, while a mean-field dynamo organises them in to large scale structures. Recently, it has become possible to start testing these models using polarised far-infrared observations of heated dust in gravitationally lensed dusty star-forming galaxies (DSFGs). By combining ALMA's high resolution with the magnifying effect of gravitational lensing, it is possible to resolve magnetic field structures on sub-kiloparsec scales as far back as the Cosmic Dawn, offering a unique opportunity to study their evolution across cosmic time.
De Roo et. al (2024) present the second ever resolved detection of an ordered magnetic field structure beyond the Local Universe. However, this is the first time that the lensing configuration provides a complete view of the source-plane morphology. The authors have used the lens modelling code Pronto to model the (polarised) ALMA data directly in visibility space.
The background galaxy, known as HERS1 or 9io9, is located at redshift 2.6 and features a heated dust continuum morphology that strongly resembles a grand-design spiral, extending over 4 kiloparsecs in size. Due to the strong magnification from the two foreground lensing galaxies at redshift 0.2, the source-plane model reveals structures resolved down to 50 parsec scales, including a bright core and multiple smaller clumps that are likely sites of intense ongoing star formation. A second (full-polarisation) ALMA observation at 350 GHz reveals that the magnetic field structure in HERS1 closely follows the spiral pattern of the heated dust. Remarkably, the morphology of the magnetic field strongly resembles those observed in nearby spiral galaxies. These results demonstrate that large-scale ordered magnetic fields were already present when the Universe was just 2.6 billion years old, despite the expectation that their emergence requires at least several rotations of the disk. Future observations of additional targets will be crucial in determining whether the highly ordered magnetic field observed in HERS1 is the norm or the exception.
