So here I am at the Institut de Ciencies de L’Espai (ICE-CSIC) which is on the campus of the Universidad Autónoma de Barcelona (UAB) for the first ever Euclid Spain Meeting. This involved a 40-minute trip on the S2 train from Plaça de Catalunya, which is a short walk from my apartment, then a short walk from the railway station at UAB through the campus to the Institute.
I was able to speak at this meeting because I happen to be in Barcelona right now. I mean that I was able to attend because I was in Barcelona anyway, not that the meeting was held because I am in Barcelona!
Anyway, I gave my talk early on this morning, so have been able to enjoy the rest of the day having got that out of the way. There are about 50 people here. It’s great to see the sizable Euclid community in Spain getting together and sharing their work.
I thought it would be appropriate to add a little update about the European Space Agency’s Euclid mission. I’ll keep it brief here because you can read the full story on the official website here.
You may have seen in the news that the Euclid telescope has been having an issue with ice forming on surfaces in its optical systems, especially the VIS instrument. This is a common problem with telescopes in space, but the extent of it is not something that can be predicted very accurately in advance so a detailed strategy for dealing with it had to be developed on the go.
The layers of ice that form are very thin – just tens of nanometres thick – but that is enough to blur the images and also reduce the throughput of the instruments. Given that the objects we want Euclid to see are faint, and we need very sharp images then this is an issue that must be dealt with.
Soon after launch, the telescope was heated up for a while in order to evaporate as much ice as possible, but it was not known how quickly the ice would return and to what parts of the optical system. After months in the cold of space the instrument scientists now understand the behaviour of the pesky ice a lot better, and have devised a strategy for dealing with it.
The approach is fairly simple in principle: heat the affected instruments up every now and again, and then let them cool down again so they operate; repeat as necessary as ice forms again. This involves an interruption in observations, it is known to work pretty well, but exactly how frequently this de-icing cycle should be implemented and what parts of the optical system require this treatment are questions that need to be answered in practical experimentation. The hope is that after a number of operations of this kind, the amount of ice returning each time will gradually reduce. I am not an expert in these things but I gather from colleagues that the signs are encouraging.
Since it’s been a couple of weeks since Euclid commenced its routine survey operations, I thought I would share this little video from the European Space Agency that shows how the surveying will proceed over the next six years with explanatory text adapted from here:
This animation shows the location of the fields on the sky that will be covered by Euclid’s wide (blue) and deep (yellow) surveys. The sky is shown in the Galactic coordinate system, with the bright horizontal band corresponding to the plane of our Milky Way.
The wide survey will cover more than one third of the sky as shown in blue. Other regions are avoided because they are dominated by Milky Way stars and interstellar matter, or by diffuse dust in the Solar System – the so-called zodiacal light. The wide survey is complemented by a deep survey, taking about 10% of the total observing time and repeatedly observing just three patches of the sky called the Euclid Deep Fields, highlighted in yellow.
The Euclid Deep Field North – towards the top left – has an area of 20 square degrees and is located very close to the Northern Ecliptic Pole. The proximity to the ecliptic pole ensures maximum coverage throughout the year; the exact position was chosen to obtain maximum overlap with one of the deep fields surveyed by NASA’s Spitzer Space Telescope.
The Euclid Deep Field Fornax – in the lower right of the image – spans 10 square degrees and is located in the southern constellation Fornax, the furnace. It encompasses the much smaller Chandra Deep Field South, a 0.11 square degree region of the sky that has been extensively surveyed in the past couple of decades with the Chandra and XMM-Newton X-ray observatories, as well as the Hubble Space Telescope and major ground-based telescopes.
The third and largest of the fields is the Euclid Deep Field South – between the Large Magellanic Cloud and the Euclid Deep Field Fornax. It covers 20 square degrees in the southern constellation of Horologium, the pendulum clock. This field has not been covered to date by any deep sky survey and so has a huge potential for new, exciting discoveries. It has been planned to be observed from the ground by the Vera C. Rubin Observatory.
P.S. According to my latest calculations, I shall have retired by the time the Wide survey is completed.
I just heard some excellent news about Euclid so thought I would post a quick update here. I won’t say much because there will no doubt be official communications from the European Space Agency and the Euclid Consortium. You can find a variety of Euclid-related posts on this blog here.
Over the past few months, there has been a huge amount of activity relating to commissioning the instruments, verifying their performance, and measuring parameters of the optical system that will be needed for analysis of the huge amount of data due to come from Euclid. All this effort fed into the Mission Commissioning Results Review (MCRR) which concluded yesterday that all was well.
This is an important milestone for Euclid because, in ESA parlance, it marks the change from a project to a mission. Until commissioning, there is a project manager who works with ESA and the industrial contractors to ensure everything functions properly; when nominal operations start the project team is disbanded and the mission team takes over; and so it came to pass that the Project Manager (Giuseppe Racca) handed over the reins to the Mission Manager (Pierre Ferruit).
That’s when the role of the Euclid Consortium increases substantially. In particular the Science Ground Segment (SGS), which includes the pipelines that will process the data, has been declared to be ready for business. You can read more about the SGS here but here’s a graphic that shows how data comes from the telescope, external telescopes, or simulations, then run through their respective pipelines for VIS, NISP, or external data, then are merged into a coherent format. Pipelines then extract scientific information and compute science data products for further analysis
Each element of this diagram is rather complex. Here, for example, is the organization of the Science Data Centre (SDC) component of the Science Ground Segment at the bottom of the above picture, consisting of computing centers responsible for implementing and running the data processing pipelines:
Anyway, the immediate upshot of all this is that full surveying activities of Euclid can now proceed. The Euclid mission will conduct primarily two different surveys: a “Wide Survey”, covering about 15,000 square degrees on the sky, and a “Deep Survey” of about 50 square degrees, where the instruments will observe three fields much longer than the rest of the sky to capture much fainter galaxies and hence look further out into space. I understand that the Wide Survey will commence in earnest on 14th February.The timescale from now is that the first full set of survey data (DR1) will be available internally to the Euclid Consortium in May or June 2025 and will be made public a year later (i.e. by June 2026).
That doesn’t mean that Euclid will be silent until 2026. In fact, the first batch of post-launch papers will come out very soon, in May 2024. This will include science papers resulting from the Early Release Observations – the data from these will also be made public at the same time – as well as an overview paper for the whole mission and papers describing the details of NISP and VIS instruments using measurements made during commissioning. There will also be a release in May 2025 of data from the Deep Survey patch of about 50 square degrees.
I know that’s an obvious joke, but I couldn’t resist.
The thing that’s really awkward about Zoom calls from Australia is when the other attendees are in Europe and North America. I had to chair a (Euclid-related) telecon in the early hours of yesterday morning, which wasn’t much fun, though I think it went OK and I did manage to get some sleep afterwards.
Other than that I’ve been remarkably free of jet lag. I had received dire warnings from other colleagues who have made the trip, but it doesn’t seem to have affected me badly at all. By now I’m used to what time it is, though I still have problems with what day it is. That’s because most of the emails I get are sent from Europe and these are generally sent yesterday (my time), i.e. from a place where my today is the sender’s tomorrow. If somebody says “let’s chat tomorrow” that confuses me!
Although I haven’t had much trouble with the time difference, the one thing that I have taken time to adjust to is eating habits. I got on the plane at Abu Dhabi at 10.25pm and once the plane had reached cruising altitude they served dinner (and, of course, wine). The trouble is that was around 7am Sydney time when I should have been having breakfast. I arrived in Sydney around 7pm Sydney time, when I should have had dinner, but all I had was a craving for breakfast (especially coffee). Obviously my stomach wasn’t yet tuned in. Anyway, just two (or is it three?) days later, I’m back to having breakfast at breakfast time and dinner at dinner time so all is well.
I have now entered that strange twilight zone between Christmas and New Year during which it is difficult to remember which day is which, so I thought I’d just do a quick retrospective about the thing that has the biggest effect on my professional life in 2023, namely the Euclid satellite.
Euclid was launched halfway through the year, on July 1st, an event that took place just a week after or so after the annual Euclid Consortium Meeting in Copenhagen when I took over as Chair of the Euclid Consortium Diversity Committee. The latter led to a huge increase in the number of telecons I had to attend, not only the ECDC’s own bi-weekly Zoom meetings but also various other committees that the ECDC Chair attends ex officio. Much of the Chair’s work is confidential, which means there is no-one to consult with about the difficult matters. Had I not been on sabbatical since September I don’t think I would have had either the time or the energy to carry out these duties. It has taken me quite a while to get the hang of this role, but I do feel that it’s important and that I have contributed in a small way to the Euclid Consortium.
As for the scientific side of Euclid, after a few technical issues the commissioning of Euclid’s instruments is now more-or-less over and the final preparations are being made for the survey proper, which will take commence in the New Year. What is going on now is called a phase diversity analysis, which is being used to verify and improve the performance of the optical system.
In November, a set of Early Release Observations were published. Early in the New Year a number of scientific papers about these will be published, along with other papers about Euclid in general, including an overview paper that provides a high-level description of the mission. Data relating to the Early Release Observations will also be released to the general public.
After that the survey will begin in earnest. The full exercise will take six years to complete – I’ll have retired before it finishes – but there will be a first data release (DR1) using one year’s worth of survey data. That should give a good idea of how well it’s all going to work out for the full survey. That data will be made available to the public.
If all goes to plan, after the annual EC meeting (which next year will be in Rome, from 17th to 21st June), I’ll be stepping down as ECDC Chair and indeed from the ECDC altogether. That is just as well because my sabbatical will be over at the end of August and I’ll be back to a full teaching and admin load at Maynooth, assuming there’s still a Department to return to!
Yesterday I gave a talk at the UK Euclid Consortium (EC) Meeting in London in my role as Chair of the ECDC (Euclid Consortium Diversity Committee). I didn’t actually go to London, but delivered my talk virtually (not without a few hiccups, but I won’t go into that). My presentation was just a short one, outlining some of the things the ECDC does and encouraging others to get involved. One of the matters arising was the EC Code of Conduct, which has recently been updated. This document covers work within the EC generally, as well as specific rules governing EC-sponsored events, such as the meeting I spoke at. Incidentally, one of the latter rules is that organizers should facilitate virtual attendance at meetings, which they clearly did for me yesterday!
Coincidentally, there was a news item in Nature today that reminded me of a post on this blog from a couple of years ago. That was when news first broke of a bullying scandal at the University of Lund, specifically in the historic Lund Observatory, home of the Astronomy Department. Two professors were involved, Sofia Feltzing and Melvyn Davies. As far as I understand the situation, both are still employed by the University, in the Department of Geology and the Department of Mathematics respectively.
The latest news from Lund is that in the aftermath of this scandal, the Astronomy Department has been closed and the staff previously in it subsumed into Physics. That’s a pretty drastic step. In my experience forced mergers of departments, though popular with autocratic managers, are usually counterproductive from the point of view of staff morale. Precisely what the closure of the Lund Observatory after 350 years is meant to achieve is beyond me, but I assume that the atmosphere there had become so toxic that the authorities couldn’t think of anything else to do.
This is a demonstration of something I’ve often said in talks about EDI work. When matters come to formal disciplinary process – if they ever do – the outcome is almost never satisfactory in any respect, not least because the outcomes are often concealed by Non-Disclosure Agreements. The only really hope of creating an inclusive workplace is to ensure that bullying and harassment don’t happen in the first place, or are snuffed out very early on. Early intervention, mediation and conflict resolution are far more likely to provide a successful outcome than formal processes. The problem is that junior members of a department, who are most likely to be the target of bullying, do not feel empowered to make a complaint until it’s too late.
A binding Code of Conduct is one thing, but in order to work it has to be able to be enforced. That is why I agree with the approach suggested by the 21 Group, namely that there should be independent investigators for such matters whose conclusions are binding.
Yesterday came across the above “infographic” – as I’m told such things are called – showing the media traffic generated by last month’s Early Release Observations from the ESA Euclid mission. Some quite interesting facts emerge from it. The new observations were released n 7th November, hence the big spike in the left hand panel on that date.
I see that about 31% of the activity was on Twitter, which I am no longer on, with a slightly smaller amount on Facebook. Overall, social media account for about 60% of the “reach”, with mainstream media (including print, online, and TV/Radio) languishing far behind. Blogs (presumably including this one) account for a mere 1%.
The breakdown by country is interesting too; the table shows only EAS member states. The UK is way out in front, no doubt because BBC News ran a major item on the day of the release. France, Germany, Italy and Spain all have major scientific involvements in Euclid and correspondingly active public engagement activities.
I was pleasantly surprised at the significant amount of interest in Ireland, given that some bigger countries with far greater scientific involvement in Euclid (e.g. Denmark and The Netherlands) generated so little. As the only member of the Euclid Consortium in Ireland I could try to pretend that this was all down to me, but I rather think it’s more likely to be a result of the fact that many Irish people read the UK media so some of the Irish traffic could be spillover from the big UK spike. Still, I think one can interpret this as meaning that the Public in the Republic have an appetite for news about space, something that we have certainly noticed when organizing events in Maynooth.
I thought I’d mention another nice thing. Here is one of the PR images produced by ESA about the early release observations. The point about Euclid is that to achieve its science goals it has to have extremely good optical quality across a very wide field of view. The systems are currently being tested and fine-tuned to see how good their performance actually is, but so far it’s looking good.
The main thing that caught my eye, however, is the collection of little flags along the bottom. How nice it is to see Ireland’s among them!
The Perseus Cluster (Abell 426) – a dense concentration of over a thousand galaxies with a total mass of about 1.2 × 1015 M⊙ – is impressive in its own right, especially because the picture was taken in a single exposure, but the staggering thing about this image is that it contains hundreds of thousands of galaxies. In other words there are as many galaxies in this picture as there are words in a book. Most of these galaxies are in the background, not associated with the cluster, and many of them extremely distant. With so many objects in one field, you can perhaps see how much data we will get from the entire survey, which will last more than 6 years. It is these distant sources – billions of them – that Euclid will survey to glean information about the expansion history of the Universe.
P.S. Yesterday’s press conference resulted in a lot of media attention worldwide, even some in Ireland. There is a piece on the RTÉ website, for example, and another on Silicon Republic (which includes a quote from yours truly).
So today’s the day. The first science-quality observations from Euclid have now been released to the public. The official press release is here, and the press conference showcasing the new observations can be viewed here:
The images themselves can be found in this repository. In summary they are (in no particular order):
IC 342NGC 6822Horsehead NebulaNGC 6397Perseus Cluster
And here they are – you can click on them to make them bigger:
A few points of my own.
First, it is important to realise that these observations are not part of the full Euclid survey, which will start in early 2024, but were produced during the process of verification the capabilities of the telescope and detectors. They are all very short exposures, taking up less than a day to make all the images, but they demonstrate that Euclid is performing very well indeed!
Euclid is designed to achieve very sharp optical quality across a very wide field of view, so its strength is that it will produce beautiful images like these not only of a handful of objects but for billions. We need to map very large numbers of galaxies to perform the careful analysis needed to extract information about dark matter and dark energy, which is the main goal of the mission.
While these images are, in a sense, by-products of the Euclid mission, not specifically related to the main aims of the mission, they are interesting in their own right and there are proper scientific papers related to each of the five sets of observations released today. We expect many more non-cosmological spinoffs like these as the mission goes on.
There were some problems during the commissioning of the instruments carried by Euclid, the most serious of which was an issue with the Fine Guidance Sensor used to control the pointing of the telescope. This has been fixed by a software update and everything is now functioning well, as today’s new results confirm!
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In the Dark 