• 1 Introduction
• 2 Call for abstract submissions for National Astronomy Meeting 2025
• 3 Call for abstract submissions for EAS Annual Meeting 2025
• 4 Would you like to help set up an LSST:UK Junior Associates network?
• 5 Dwarf galaxies in focus: new MNRAS paper
• 6 4MOST project updates
• 7 Rubin Data Management meeting – report
• 8 Share the story of your journey to LSST:UK
• 9 Forthcoming meetings of interest

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Introduction

Call for abstract submissions for National Astronomy Meeting 2025

The National Astronomy Meeting (NAM) 2025 is being held at Durham University from 7-11 July. The programme includes both parallel and lunch sessions about Rubin/LSST: #62 Enabling early science with Rubin/LSST in 2025, and #93 LSST and LSST:UK for Early Career Researchers.

Submission of talk and poster abstracts for both sessions are very welcome from everyone in the community. The deadline for abstract submission is 30 March, and is via the NAM 2025 web-site linked above.

We envisage members of the newly established LSST:UK Junior Associates Network taking the lead in organising the latter session (#93), as it is focused on the needs of Early Career Researchers. Overall, both sessions aim to encourage and equip the community to engage with the ComCam data and achieve some exciting early science this summer as DP1 is released to data rights holders.

Further details of both sessions, and what to expect, are available from the abstracts linked above, or from the organisers of these sessions, who span a broad range of career stages and science interests. We look forward to seeing you in Durham!

@Graham Smith @Bob Mann

Call for abstract submissions for EAS Annual Meeting 2025

The European Astronomical Society (EAS) has organised a special session on Rubin at its Annual Meeting. The event takes place from 23–27 June 2025 in Cork, Ireland.

The Special Session (SS5), The Vera C. Rubin Observatory Legacy Survey of Space and Time: a European Pathway from First Look to Data Flows, will focus on three areas:

• the Rubin Observatory ecosystem and the role of the Science Collaborations

• early science with public alerts and synergies with other surveys

• doing science with Rubin-LSST, together.

The EAS is inviting all scientists – whether already involved or new to Rubin-LSST – to submit an abstract for a contributed talk, an ePoster or an ePoster with flash talk. The deadline for abstract submission is 3 March. Early career researchers are particularly encouraged to submit a contribution.

The deadline for abstract submissions is 3 March 2025. Read more at https://eas.unige.ch/EAS2025/abstract_submission.jsp
If you have any questions, email Giada Pastorelli (gpastorelli.astro@gmail.com) or Matthew Temple (Matthew.J.Temple@durham.ac.uk)

Matthew Temple

Would you like to help set up an LSST:UK Junior Associates network?

As the start of Rubin LSST survey operations approaches, we are keen to establish a Junior Associates (JAs) network within LSST:UK, to help ensure that the Consortium provides JAs with the information, training and guidance they require to engage to the fullest extent in the wider LSST community, as well as providing a mechanism for having the particular concerns of JAs heard within the LSST:UK leadership, through representation on the Consortium Board and Executive Group.

Evidence from analogous groups in other large consortia – such as the Junior DESC Organisation (JuDO) and UK SKAO Science Committee’s Early Career Researcher Group – suggest they work best when they are self-organising, so we would like to hear from JAs who would be interested in helping set up the new network. We have a lunchtime session at NAM2025 on LSST and LSST:UK for Early-Career Researchers and would like that to include the launch of the network, providing an outline of the kinds of things it might do (and the support that LSST:UK can provide it).

So, please email us (rgm@roe.ac.uk and gps@star.sr.bham.ac.uk) if you are a JA who would like to be involved in setting up the network, and we will arrange a couple of Zoom meetings to discuss it more thoroughly and to prepare for the NAM lunchtime session.

@Bob Mann and @Graham Smith

Dwarf galaxies in focus: new MNRAS paper

Aaron Watkins and co-authors have recently had a paper accepted for publication in MNRAS: 2D light distributions of dwarf galaxies – key tests of the implementation of physical processes in simulations. 

Dwarf galaxies, being low-mass systems, are expected to be sensitive to energetic phenomena such as supernova feedback. @Aaron Watkins and co-authors examined the structures of simulated cluster dwarfs in the high-resolution NewHorizon cosmological zoom simulation, creating realistic mock images of the galaxies and deriving their sizes, surface brightnesses, and other properties using established observational techniques. The group then compared these properties to those of real dwarfs, measured using identical methods, found in the nearby Fornax Cluster.  Per unit stellar mass, the simulated dwarfs are much larger and more diffuse than their real counterparts, with the discrepancy increasing with decreasing stellar mass. To isolate environmental from internal effects, Watkins et al. compared these simulated cluster dwarfs both with simulated dwarfs in more isolated regions, as well as with observed Local Group and field dwarfs. 

While some subtle differences can be found between environments in observed dwarfs, the largest discrepancy is between observed and simulated dwarfs, regardless of environment.  This suggests that the simulated dwarfs' extended sizes are mostly a result of how energetic feedback is implemented in the simulation, possibly coupled to resolution effects at early stages of evolution when galaxies are comprised of only a handful of particles each. 

With the enormously expanded sample of dwarf galaxies expected to be observed with LSST, the subtle population differences hinted at in this study can be further explored, potentially leading to critical refinements of feedback implementations in simulations and the synthesis of more realistic simulated dwarf galaxies.

@Aaron Watkins

Read the paper: 2D light distributions of dwarf galaxies – key tests of the implementation of physical processes in simulations, @Aaron Watkins, @Garreth Martin , @Sugata Kaviraj, @Chris Collins, Y Dubois, K Kraljic, C Pichon, S K Yi

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Above: Comparing effective surface brightness and effective radius vs. stellar mass relations from a variety of different studies. Red triangles show the FDS relation and black points show our NH group dwarf values. Purple crosses show values for Local Volume dwarf satellites from Carlsten et al. (2021). Orange squares denote measurements by Jackson et al. (2021) also of galaxies in the two largest NewHorizon groups, but made using the unattenuated intensity-weighted second moments of the particle distributions. Orange contours underlying these points outline the distributions for all NewHorizon galaxies from Jackson et al. (2021). Blue squares are from Lazar et al. (2024), for z<0.08 dwarfs from the COSMOS2020 catalogue.

4MOST project updates

4MOST (4-Metre Multi-Object Spectroscopic Telescope) is an upcoming facility on ESO’s VISTA at Paranal.

4MOST packs ~2,400 fibre optic cables that can individually be articulated and positioned on a target in the 4.2 square degree field of view. This facility will obtain spectra for tens-of- millions of stars and galaxies over its five-year lifetime. LSST:UK is strongly involved in 4MOST through one of its work packages to enable the spectroscopic follow-up of supernovae and their host galaxies in a sub survey known as TiDES.

TiDES will collect the largest sample of transient events of any spectroscopic survey ever, and use this data to make the most precise measurement of the dark-energy equation of state parameter, w. 4MOST is still being shipped and installed at Paranal, 2025 will be a critical year as we expect to complete construction and start commissioning this summer followed by the start of survey operations in early 2026. Here we report on two major milestones:

First 4MOST Component Installed on VISTA

On 9 June 2024, we celebrated a significant achievement: the installation of the very first 4MOST component, known as the Cassegrain Cable Wrap (CaCW), onto the VISTA telescope. This large and essential part, crafted by the Leibniz Institute for Astrophysics Potsdam (AIP) with help from the Max Planck Institute for Astronomy (MPIA) was shipped to Paranal in two sea containers. A team from AIP Potsdam and ESO Garching worked to unpack, inspect, and install the CaCW. Thanks to their expertise and the excellent support from ESO, the installation was completed ahead of schedule without any major hitches. Roelof de Jong, the Principal Investigator for 4MOST, praised the team's smooth collaboration and expressed optimism for future installations in the coming months.

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The installation team from AIP, ESO Garching, and ESO Paranal in front on CaCW installed on the VISTA.
(Credit: Joar Brynnel)

First Technical Light

Following successful installation campaigns in October and November, 4MOST partnered with ESO to ensure the VISTA telescope was ready for its next phase. On 22 November 2024, we reached a crucial milestone confirming the telescope’s readiness to integrate the new 4MOST hardware, including the Wide Field Corrector and the Acquisition & Guiding and Wave Front Sensing systems.

Recommissioning began on 24 November, marking an exciting return of the VISTA telescope to active observation. The hard work paid off on 5 December, when we captured our first ‘Technical Light’ image – a stunning photo of the galaxy NG2207 (pictured right). This impressive image not only showcases the enhanced capabilities of VISTA with 4MOST, but also boosts our confidence in the system’s performance.

@Christopher Frohmaier

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4MOST First Technical light image: NGC2207 and IC2163, a pair of overlapping and probably interacting spiral galaxies at about 17 Mpc (55 million light year) distance, surrounded by much nearer stars in our own Galaxy. (Credit: 4MOST Consortium and ESO)

Rubin Data Management meeting – report

In mid-February, the French Data Facility team hosted an important Rubin Data Management meeting at their headquarters on the Campus of Claude Bernard University Lyon 1. The focus of the event was to review progress with the computing elements of telescope commissioning and to finalise preparations for the beginning of telescope operations, currently expected to start in late 2025.

 Around 30 staff and in-kind members of the Data Management team – from USA, France, and UK – contributed to the three-day workshop, which was a mix of technical and management discussions, as well as hands-on workshops and breakout sessions.

A key responsibility of Data Management is the preparation of the annual LSST Data Releases, which creates and then delivers the complete set of science-ready data products to the astronomy community via the various Data Access Centres (DAC) and Science Processing Centres (SPC), including the UK IDAC in Edinburgh. Data Release Processing will be jointly undertaken by three facilities: the US Data Facility, hosted at the Stanford University Accelerator Laboratory (SLAC), the French Data Facility, hosted at the Institut National de Physique Nucléaire et de Physique des Particules (IN2P3), and the UK Data Facility which is jointly hosted at the University of Lancaster and at Rutherford Appleton Laboratories in Didcot.

 The meeting was positive and productive, building on what is turning out to be a very impressive first phase of telescope commissioning, and on some recent team achievements in the preparation for multi-site processing, including the first full end-to-end processing run across the three facilities.

The early science programme was a focus of discussions, supported by a new version of the Rubin technical report RTN-011, detailing new stretch goals for the first on-sky dataset (Data Preview 1) to include deep coadded images, forced source catalogues, and difference images (and associated catalogues).

Detailed plans were developed to scale up multi-site operations, completing the move of routine Science Pipeline testing to the French and UK Data Facilities, to free up capacity at the US Data Facility for further commissioning work, and kicking off large-scale processing of precursor data from the HSC telescope aiming to reach and sustain the operational processing rate required for the first LSST Data Release.

The Campaign Management team previewed the next iteration of CM-Service, the software suite that provides the tools that processing scientists need to enact and monitor Data Release Processing and finer details of science validation and incident response were discussed.

The team also looked at technology roadmaps for key DM services, such as PanDA (the workflow manager) and Rucio (the distributed data-management system), and at opportunities to incorporate new technologies, such as tape-based archiving to reduce costs, ARM-based compute to improve energy efficiency, and information-security innovations to help protect DM integrity.

Lyon was a great venue for the meeting, with its vibrant and diverse culture, a chance to sample fine French cuisine, and some time to explore the history and heritage of France’s second-largest city.

Sadly, the weather was typical for February – cold and a bit rainy. However, the plan is to hold the next Joint Data Facility Meeting in Edinburgh, so we probably shouldn’t complain too much about the weather!

@George Beckett

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Attendees of the Rubin Data Management meeting, which took place in Lyon.
(Credit: William O'Mullane)

Share the story of your journey to LSST:UK

We’re launching a series of interviews to highlight people working across all areas of the project in a new series entitled LSST:UK in the Spotlight. Take a look at this webform and answer questions about your passions as well as your pathway into your current role.

You’ll help us show how astronomy is an exciting and rewarding subject that welcomes people with different backgrounds, talents and interests. These interviews will be published in this newsletter and on the LSST:UK website when it relaunches. We will also use snippets on our social media channels.

Everyone is encouraged to participate. I will come back to you to let you know when your interview is planned to go live, to run the text past you for final approval and to request a headshot or other image relating to you and your work. If you have any questions, get in touch with Eleanor O’Kane, LSST:UK Communications Officer: eokane@roe.ac.uk

@Eleanor O'Kane

Forthcoming meetings of interest

Dates, locations and links… The current list of forthcoming meetings is always available on the Relevant Meetings page. You may also wish to check information held on the LSST organisation website LSST-organised events and the LSST Corporation website.