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".
In preparation for the ALMA Cycle 12 proposal deadline on 24th April 2025, the Italian node of the European ALMA Regional Centre (ARC) is organising a community meeting (in person and online) on Friday 4th April 2025. This meeting is to inform all potential users of new capabilities and the most important changes concerning the proposal preparation and the available tools.
Allegro offers support for ALMA users preparing proposals for Cycle 12. Users can request support via e-mail (alma@strw.leidenuniv.nl) at any time. Turn around time for answers will be especially fast during the Allegro proposal-preparation office hours, from 15:00-17:00 on April 8, 10, 15, 17, 22 and 24; outside these hours, we aim to answer your questions within 1 working day.
The next Call for Proposals for observing time with ALMA (Cycle 12) is anticipated to be issued on 20 March 2025, with a deadline on 25 April 2025. As a focal point during the proposal preparation period, the German ARC node cordially invites its community to gather for the German ALMA Community Day 2025 at the Argelander-Institut für Astronomie in Bonn on Friday, 4 April 2025.
In preparation for the upcoming ALMA proposal deadline (April 24), the Nordic ARC node is preparing a few events to which the community is invited. On April 1 and 10, we meet at Chalmers University, Gothenburg (Sweden), for two in-person proposal preparation events. And for April 8-9 we are preparing and ALMA proposal preparation workshop at the University of Helsinki, Finland. Everyone is welcome to attend.
Lunch session LS6 on "The ALMA 2030 Wideband Sensitivity Upgrade: status update" will take place on the 26th of June, during the European Astronomical Society (EAS) 2025 annual meeting in Cork (Ireland).
We would like to announce the new monthly AtLAST forum series. This forum is open to everyone and it is held every first Thursday of the month on this Zoom link. The format is: two 15-min long talks followed by a plenary discussion session. This online event is scheduled either at 8:00 UTC or at 14:00 UTC, alternating between these two times to be more timezone-friendly.
The upcoming AtLAST fora are on Thursday 6 March (14 UTC) and 3 April (8 UTC). For further details, see this webpage.
140 pc resolution dust and [CII] imaging in the first billion years
Dust continuum emission (left) and [CII] 158 micron emission line (right) maps of J0305-3150. The 0."026 (140 pc) beam is shown in the top left corners, and the position of the quasar is shown with a white star. The emission is resolved over >300-400 resolution elements at SNR>2 spread over ~4 kpc. The different morphologies are immediately clear, highlighting the different origins of dust continuum and [CII] emission.
High redshift quasars are unique tracers of massive galaxies well into the first billion years of the Universe. Sub-mm observations probe their far-infrared spectrum at z>6, with ALMA particularly suited to resolve their ISM. Their FIR luminosities (>10^13 Lsun) rival or surpass that of local ULIRGS and HyLIRGS, with corresponding extreme star-formation rates (SFR~1000-3000 Msun/year). Quasar host galaxies are thus laboratories to study the most massive and rapidly star-forming galaxies in the early Universe, and ALMA can uniquely probe the dust and gas reservoirs supporting the growth of their central SMBH and the associated starbursts.
As part of a continuing effort to resolve the ISM of these early giants, ALMA has observed the z=6.6 quasar J0305-3150 at a resolution of 0."026 (140 pc at z=6.6, Meyer et al. 2025). These observations reveal strikingly different morphologies of dust and [CII] 158 microns emission, a major coolant of the ISM and one of the most studied FIR line with ALMA in extragalactic sources. The dust continuum emission is mostly compact with the detection of several star-forming clumps (r<200 pc), whereas the [CII] image shows a diffuse morphology with extended emission detected up to 10 kpc. Compiling all the ALMA archival data on this object (configurations C43-5 to C43-10) and re-imaging the quasar with different maximum resolvable scales shows that 50% of [CII] is emitted by structures with large physical scales (>10 kpc), not compact clumps located at large galactocentric radii. Furthermore, the small-scale and large-scale [CII] emission show different kinematics, with the latter being aligned with nearby merging companions and an extended Lyman-alpha halo. This lead to the interpretation that unlike the dust continuum, which traces dense clumps of the ISM, [CII] traces diffuse HI gas that can be found both in the ISM as well as in the outskirts of a galaxy when disrupted by a merger. These observations shed a new light of the nature of [CII] at high redshift and show the incredible resolution of ALMA when pushed to its limits (140 pc at z=6.6!).
Contributed by Romain Meyer
ALMA poll of the month
The Cycle 12 call for proposals is anticipated to be released on 20 March 2025 with a deadline on 24 April 2025 (see this link for more information)
Results from January's poll, "Will you be submitting an observing proposal using the forthcoming Band 2?"
Did you know?
Self-calibration could signficantly improve the quality of your ALMA data. The EU ARC Network's I-TRAIN series includes tutorials on self-calibration if you want to learn this technique!
If you would like to contribute an ALMA science highlight, please contact the newsletter editor at Hannah.Stacey@eso.org.
