Archive for the Euclid Category

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Euclid finds an Einstein Ring

Posted in Euclid, The Universe and Stuff with tags , , , , , , on February 10, 2025 by telescoper

What better way to start a cold February morning than with a lovely image from Euclid? The picture above on the left shows an image of the galaxy NGC 6505 and on the right a closer view of the central portion that reveals a near perfect Einstein Ring. This phenomenon is caused by gravitational lensing and is quite a rare occurrence because it requires a perfect alignment between a background source, a concentration of mass that acts as a lens, and the observer (in this case the Euclid telescope):

This find is all the more extraordinary because it was made using observations made during Euclid’s commissioning phase when the telescope was not yet fully focussed. The first release of (a small sample) of full-quality data from Euclid – the so-called Q1 release – will actually be announced next month.

The published paper by O’Riordan et al is available here, from which I have taken this image showing the two relationship between the two images above:

There has already been quite a lot of media coverage of this discovery (even in Ireland). Here is the Press Release from the European Space Agency explaining the background and some comments from people involved in the work:

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Euclid blasted off on its six-year mission to explore the dark Universe on 1 July 2023. Before the spacecraft could begin its survey, the team of scientists and engineers on Earth had to make sure everything was working properly. During this early testing phase, in September 2023, Euclid sent some images back to Earth. They were deliberately out of focus, but in one fuzzy image Euclid Archive Scientist Bruno Altieri saw a hint of a very special phenomenon and decided to take a closer look.

“I look at the data from Euclid as it comes in,” explains Bruno. “Even from that first observation, I could see it, but after Euclid made more observations of the area, we could see a perfect Einstein ring. For me, with a lifelong interest in gravitational lensing, that was amazing.”

The Einstein Ring, an extremely rare phenomenon, turned out to be hiding in plain sight in a galaxy not far away. The galaxy, called NGC 6505, is around 590 million light-years from Earth, a stone’s throw away in cosmic terms. But this is the first time that the ring of light surrounding its centre is detected, thanks to Euclid’s high-resolution instruments.

The ring around the foreground galaxy is made up of light from a farther out bright galaxy. This background galaxy is 4.42 billion light-years away, and its light has been distorted by gravity on its way to us. The far-away galaxy hasn’t been observed before and doesn’t yet have a name.

“An Einstein ring is an example of strong gravitational lensing,” explains Conor O’Riordan, of the Max Planck Institute for Astrophysics, Germany, and lead author of the first scientific paper analysing the ring. “All strong lenses are special, because they’re so rare, and they’re incredibly useful scientifically. This one is particularly special, because it’s so close to Earth and the alignment makes it very beautiful.”

Albert Einstein’s general theory of relativity predicts that light will bend around objects in space, so that they focus the light like a giant lens. This gravitational lensing effect is bigger for more massive objects – galaxies and clusters of galaxies. It means we can sometimes see the light from distant galaxies that would otherwise be hidden.

If the alignment is just right, the light from the distant source galaxy bends to form a spectacular ring around the foreground object. These Einstein rings are a rich laboratory for scientists. Studying their gravitational effects can help us learn about the expansion of the Universe, detect the effects of invisible dark matter and dark energy, and investigate the background source whose light is bent by dark matter in between us and the source.

“I find it very intriguing that this ring was observed within a well-known galaxy, which was first discovered in 1884,” says Valeria Pettorino, ESA Euclid Project Scientist. “The galaxy has been known to astronomers for a very long time. And yet this ring was never observed before. This demonstrates how powerful Euclid is, finding new things even in places we thought we knew well. This discovery is very encouraging for the future of the Euclid mission and demonstrates its fantastic capabilities.

By exploring how the Universe has expanded and formed over its cosmic history, Euclid will reveal more about the role of gravity and the nature of dark energy and dark matter. The space telescope will map more than a third of the sky, observing billions of galaxies out to 10 billion light-years. It is expected to find around 100 000 strong lenses, but to find one that’s so spectacular – and so close to home – is astonishing. Until now, less than 1000 strong lenses were known, and even fewer were imaged at high resolution.

“Euclid is going to revolutionise the field, with all this data we’ve never had before,” adds Conor.

Although this Einstein ring is stunning, Euclid’s main job is searching for the more subtle effects of weak gravitational lensing, where background galaxies appear only mildly stretched or displaced. To detect this effect, scientists will need to analyse billions of galaxies. Euclid began its detailed survey of the sky on 14 February 2024 and is gradually creating the most extensive 3D map of the Universe yet. Such an amazing find, so early in its mission, means Euclid is on course to uncover many more hidden secrets.

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Who will stand up for LGBTQ+ Diversity?

Posted in Biographical, Euclid, LGBTQ+, Politics with tags , , , on February 3, 2025 by telescoper
Progress Pride flag

The only thing that has surprised me about Donald Trump’s assault on Diversity, Equity and Inclusion is the speed with which he has imposed his bigotry on individuals and federal institutions. The first step came within hours of the Felon-in-Chief assuming office with an Executive Order intended to dismantle crucial protections for transgender people and deny the validity of gender identity itself. The new order withdraws a range of executive orders issued by Joe Biden, including those allowing transgender people to serve in the military, advancing the health and well-being of lesbian, gay, bisexual, and transgender (LGBT) youth, and interpreting federal sex discrimination protections in domains like education, housing, and immigration to prohibit discrimination based on sexual orientation or gender identity. And this is just the start, and I don’t think it will be confined to the USA for very long.

The attack on LGBTQ+ rights is part of a wider assault on the Diversity, Equity and Inclusion policies intended to create a level playing field for women and minorities. The intention is to turn the Federal government into a system of oppression operated by people of Trump’s hate-filled mindset that diversity is a threat to white male privilege and must be crushed. He and his crony Elon Musk got where they are not by merit but through inherited wealth. It’s no surprise that they wish to deny others the chance to succeed.

I have addressed the question “why should we care about diversity?” many times on this blog in many contexts, though usually in science and usually in reference to LGBTQ+ rights. The obvious answer _ think – is based on notions of fairness: we should do everything we can to ensure that people have equal opportunity to advance their career in whatever direction appeals to them. But I’m painfully aware that there are some people for whom arguments based on fairness simply don’t wash. Trumpists, for example. For them there’s another argument that should work better. As scientists whose goal is – or should be – the advancement of knowledge, the message is that we should strive as hard as possible to recruit the brightest and most creative brains into our subject. That means ensuring that the pool from which we recruit is as large and as diverse as possible. In large and complex research collaborations, such as the Euclid Consortium (of which I am a member), the range of ideas and perspectives is a real asset when it comes to solving problems. The problem is that this argument doesn’t work either as they are driven purely by mean-spirited ideology and the desire to fill the institutions of state with those of a similar ilk.

The effects of the latest reactionary steps are already starting to show in the area of astronomy. The Diversity and LGBT+ channels on the Vera Rubin-LSST Slack (which is a Federal project, funded by the National Science Foundation and the Department of Energy) have already been deleted. A similar fate has befallen the Space Telescope Science Institute (funded by NASA). It seems to me unlikely that NASA itself will survive long as Musk will have his eyes on dismantling it and using its resources for his own vanity projects.

Over the past year I have given a few talks about my own career in research as an LGBTQ+ person; see for example here. In giving these talks I tried to strike a relatively positive tone, showing how LGBTQ+ rights have improved over the 40 years or so I’ve been involved in cosmological research since I started my graduate studies in 1985. I have, however, ended with a warning that the forces of reaction were gathering, and all the progress we have made could easily be put into reverse. That is exactly what is happening now in the USA.

The question in my mind is who will stand up for diversity? I can quote examples from my own life that prove that some individual institutions have never really taken LGBTQ+ bullying and discrimination seriously. Others may be genuinely supportive, but perhaps that is wishful thinking. It is notable how enthusiastically some US organizations have preemptivly cooperated with Trump’s edicts, even when paused through legal challenge. I grew up in the 1980s when the climate was filled with homophobic hate. It is naive to imagination that all that hate simply disappeared. We will find out very soon whether our self-styled “allies” have only ever been fair weather friends who will happily abandon us when we become politically inconvenient.

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Page Charges at A&A

Posted in Euclid, Open Access with tags , , , , , on January 20, 2025 by telescoper

The journal Astronomy & Astrophysics (A&A for short) announced last week that it was increasing page charges on longer papers. The table of new charges to be implemented is here:

A&A is published on behalf of the European Southern Observatory by EDP Sciences (Édition Diffusion Presse Sciences) which began life as a joint venture of four French learned societies in science, mathematics, and medicine. The company was acquired in 2019 by  China Science Publishing & Media (which has headquarters in Beijing). Judging by its social media activity, EDP Sciences sees A&A as a flagship journal; for a list of other journals it runs see here. I gave some background on A&A here.

A&A publishes papers through a curious hybrid model called “S2O” (Subscribe to Open; not to be confused with “420”). This is not fully Open Access because it requires libraries to pay a subscription to access the journal. For this reason it is not compatible with some institutional open access policies. Unlike some journals, however, A&A does allow authors to place their papers on arXiv without restriction, so they can be read there for free. Previously A&A required authors (or their institutes) to pay “Page Charges” – essentially an Article Processing Charge (APC) – if they were not from a “member country”; this policy was introduced in 2020. Authors from a member country will now have to pay APCs to publish (if their paper exceeds the page limit) but their institutional libraries still have to pay a subscription if they are to access the paper. In other words, A&A is double-dipping.

According to A&A,

… the average length of papers has also been increasing. Too often, papers are longer than necessary, leading to increased workload for authors, referees, and editors, and hindering the reader’s ability to efficiently grasp their content. As well as needing logistical consideration, the challenges related to the journal’s growth have financial implications that must be addressed to ensure long-term sustainability.

I agree that many papers are far too long. As a journal Editor myself I know that it is much harder to find people willing to review very long papers, a fact that some authors seem reluctant to recognize. On the other hand I very much doubt that any of the funds generated by page charges will be given to the refeees who do the most important – indeed I would argue the only important – work of a journal.

If the desired effect is to reduce the number of long papers this policy may work, though I suspect authors who are incurably prolix will respond by splitting their work into several shorter papers to avoid the page charges and thereby generating even more work for the journal. I suspect however that the desired effect is really to increase revenue; so often in the context of academic publishing “sustainability” really means “profitability”. I would also bet that these charges will increase further in future.

The changing charges at A&A have widespread implications, including for the Euclid Consortium, most of whose scientific papers are published there. I’m sure the Euclid Consortium Editorial Board will discuss this development. I’m not a member of the ECEB so it would be inappropriate to comment further on publication policy so I’ll leave the discussion to them. I would say, however, that the publication process at A&A is rather slow. The main post-launch Euclid Overview paper by Mellier et al., for example, was accepted for publication in August 2024 but has still not appeared. It is, however, available on arXiv, which is all that really matters. That paper, incidentally, is over 90 pages long. According to the table above that would cost about €12,000 in page charges. It was submitted in May 2024 and accepted quite quickly but is planned to appear in a special issue Euclid on Sky the publication of which is being delayed by other papers still going through the editorial process.

(Incidentally, Mellier et al. has already acquired 157 citations despite not yet being officially published, which illustrates how little difference “official” publication is actually worth.)

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The Fires of Los Angeles

Posted in Biographical, Euclid with tags , , , , on January 10, 2025 by telescoper

The wildfires that broke out on 7th January in various parts of Los Angeles have now been raging for three days and, initially driven by very high winds, have destroyed thousands of properties. Almost 200,000 people have been forced to evacuate their homes but so far it seems the loss of life has been limited. Let’s hope it stays that way, though realistically the death toll will probably rise.

The fire that broke out in the Eaton Canyon is still burning over a large area to the North-East of Los Angeles near Pasadena, which is the location of the California Institute of Technology (Caltech), NASA’s Jet Propulsion Laboratory (JPL) and the Carnegie Observatories. Through astrophysics and cosmology I know quite a few people working at these establishments, including members of the Euclid Consortium. As far as I know neither place has been directly affected by the fires, though they have been closed due to heavy smoke and wind damage. I found out today, however, that some colleagues working there and living nearby have lost their homes and all their possessions to the flames. At least they themselves – and their families – are safe and accounted for but it must be a very grim time for them.

When the smoke has cleared I hope they will get practical assistance needed to start that process. In that vein, I see that a Caltech and JPL Disaster Relief Fund has been set up. You might consider making a donation.

On a more personal note I have an old and dear friend – not an academic – who lives near Santa Monica in the area marked on the map as Palisades Fire. Looking at the satellite pictures it seems his home has been destroyed too. It was, however, placed under an evacuation order some time ago. I assume he complied and is safe and sound, though I have so far been unable to contact him.

My thoughts are with anyone affected by these terrible events.

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2025: The Year Ahead

Posted in Biographical, Euclid, Maynooth with tags , , , , on January 1, 2025 by telescoper 
For last year’s words belong to last year’s language
And next year’s words await another voice.
And to make an end is to make a beginning.

From Four Quartets, ‘Little Gidding’ by T. S. Eliot.

January is named after the Roman deity Janus, who according to Wikipedia, is the god of beginnings, gates, transitions, time, duality, doorways, passages, frames, and endings. Since I did a retrospective post yesterday about 2024 in retrospect, I thought I’d do a quick one today (1st January 2025) to mention a few things looking forward.

January will, as usual, be dominated by examinations, and especially the marking thereof. The first examination for which I am responsible is on January 13th.

February sees the start of a new semester. I’ll be teaching Particle Physics for the first time at Maynooth. I taught this subject for many years at Nottingham and Cardiff (the latter combined with Nuclear Physics), so it should be OK. My other module is Computational Physics which I have taught at Maynooth every year since 2018, apart from 2024 when I was on sabbatical.

The big event in March will be the release of “Q1” data from Euclid. This is only a very small part of the full survey, but is an important milestone and will no doubt attract a lot of press coverage. There’s a blog post by Knud Jahnke here. No doubt I’ll do a few blog posts too. The first full data release DR1 will take place in 2026. The Q1 release is timed to coincide with the annual Euclid Consortium Meeting, which this year takes place in Leiden. I won’t be able to attend in person, as it happens during teaching term, but may be able to follow some of the sessions remotely.

In April we will have a very special visitor to Maynooth to deliver the Dean’s Lecture (of which more anon). Much less significantly, I’ll be giving a Colloquium in the Department of Physics.

May will largely be taken up with second semester exams and assessments – there will be a lot of computational physics projects to correct as well as the usual examinations.

The annual meeting of the European Astronomical Society takes place in Cork in June. I’ve been to Cork before, but am looking forward to going again.

And then it will be summer. I did a lot of travelling during my sabbatical so I am not planning to travel much in 2025, though I may try to visit some more places in Ireland. Hopefully I’ll be able to get on with some research too. This year I am supervising my first MSc project at Maynooth, so that will be an interesting new experience.

And then we’re more-or-less into the next academic year 25/26. That’s beyond my planning horizon. I don’t know what I’ll be teaching, but it may be the same as 2024 (at least for Semester 1). I wonder if I’ll get to teach any astrophysics or cosmology here before I retire? It doesn’t look likely…

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Sonification of a Galaxy

Posted in Euclid, The Universe and Stuff with tags , , , on December 19, 2024 by telescoper

Here’s an intriguing experiment in sonification of an image from Euclid.

And here’s the official blurb about it:

An ethereal dance of misty clouds of interstellar dust with a myriad of distant stars and galaxies speckled like paint drops over a black canvas. This is a sonification of a breathtaking image taken by ESA’s Euclid space telescope of the young star-forming region Messier 78.

The sonification offers a different representation of the data collected by Euclid, and lets us explore the stellar nurseries in M78 through sound. Close your eyes and listen to let the cosmic image be drawn by your mind’s eye, or watch as the traceback line in this video follows the sounds to colour the image from left to right.

The twinkling sounds of various pitches and volumes represent the galaxies and stars in the frame. The pitch of the sound points towards where we see the dot of light in the image. Higher pitches tell us that a star or galaxy appears further at the top in the image along the traceback line.

The brightness of these objects in and around M78 are represented by the volume of the twinkles. Whenever we hear a particularly loud clink, the star or galaxy that Euclid observed appears particularly bright in the image.

Underlying these jingling sounds, we can hear a steady undertone, made up of two chords which represent different regions in Messier 78. This sound intensifies as the traceback line approaches first the brightest, and later the densest regions in the nebula.

The first two deeper crescendos in this undertone indicate two patches in the image where the most intense colour is blue/purple. These appear as two ‘cavities’ in M78, where newly forming stars carve out and illuminate the dust and gas in which they were born.

The chords intensify a third time at a slightly higher pitch corresponding to the red-orange colours in the image, as the sound draws over the densest star-forming region of the frame. This stellar nursery is hidden by a layer of dust and gas that is so thick that it obscures almost all the light of the young stars within it.

As the sound traces over the entire Euclid image, these different tones together form a cosmic symphony that represents the image of Messier 78, and the stars and galaxies that lie behind and within it. You can read more about this image that was first revealed to the eyes of the world earlier this year here: https://www.esa.int/Science_Explorati…

Many thanks to Klaus Nielsen (DTU Space / Maple Pools) for making the sonification in this video. If you would like to hear more sonifications and music by this artist, please visit: https://linktr.ee/maplepools

P.S. The first sentence of the Wikipedia page on sonification uses the word “perceptualize”. Ugh!

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Space Warps from Euclid

Posted in Euclid, The Universe and Stuff with tags , , , , , on November 24, 2024 by telescoper

A few months ago I posted about a joint initiative between Euclid and Galaxy Zoo that involved engaging members of the public in a project involving galaxy morphology. Well, a new “collab” (as you young people call such things) has just been announced on social media, and I encourage you to investigate further

The new venture is called `Space Warps – ESA Euclid’, and its aim is to find strong gravitational lenses in Euclid survey images. You can find out more about this project in this blog post by Knud Jahnke and you can find instructions and sign up for the project here.

The announcement of this initiative gives me an opportunity to pass on a little update on progress with the Euclid survey. The first `Quick’ Data Release (known to its friends as Q1) was made available to Euclid Consortium members just a few weeks ago. This will be made available to the general public next March, around the same time as the joint ESLAB and Euclid Consortium meeting in Leiden next year.

The Euclid survey is constructed as a set of contiguous `tiles’ covering the survey region, which will ultimately be about 15,000 square degrees (about one-third of the sky), with most of the region scanned by the satellite many times. The Q1 data will just be a taster of this. The main component of the Q1 data relates to a single visit (at the depth of the Euclid Wide Survey) over the Euclid Deep Fields (EDFs): 20 deg2 of the EDF North, 10 deg2 of EDF Fornax, and 23 deg2 of the EDF South. The deep fields will subsequently be visited multiple times during the mission.  The Q1 release will be of Level 2 data, i.e. data at the level of individual tiles.

The first full data release (DR1) is due to be published in June 2026.

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A Taste of the Euclid Survey

Posted in Euclid, The Universe and Stuff with tags , , , on October 15, 2024 by telescoper

Today (15th October 2024) saw the release of a sneak preview of the main survey of the European Space Agency’s Euclid survey at the International Astronautical Congress in Milan. Here’s the key image.

This image is not at full science resolution of the Euclid survey and is meant primarily as an appetizer. The resolution is11Kx4K,  and is processed by the same pipeline that produced the Euclid Early Release Observations featured here and here. You can find more detail about these images here and here. I have taken this from the latter article:

Euclid has been surveying the sky since 14 February 2024 and data processing is in full swing – the first public release of 53 deg² of science-grade Wide Survey data will take place in March next year. But how much data has Euclid already observed and how can we possibly visualize this? At a rate of 10 deg² per day, the Euclid Wide Survey has already surpassed 1000 deg², that is 5000x the apparent size of the Moon in the sky! Now ESA has put out a first set of images that allow to grasp how much data Euclid is and will be producing.

There’s also this explanatory video:

This is just taster. The main survey will take many years to complete. But it’s a start…

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Space Week 2024: The Universe according to Euclid

Posted in Biographical, Books, Talks and Reviews, Euclid, The Universe and Stuff with tags , , , , , on October 10, 2024 by telescoper

I had a very busy day yesterday culminating in the Space Week event I blogged about a few weeks ago. There was a good attendance – lots of young kids as well as adults – and the lecture room was very full. We could probably have filled a much bigger room, actually, but had been moved to a smaller venue and had to close registrations very early to avoid having too many people. I’d guess we had about 350. My talk was the last one, and didn’t finish until 8.30 by which time I was definitely ready for a pint.

You can find the slides I used for my presentation, The Universe according to Euclid, here.

There was an official photographer there who took quite a few pictures but I haven’t seen any of them yet. I’ll post a selection if and when I get them.

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52 Weeks of Euclid in Space

Posted in Euclid with tags , , on October 7, 2024 by telescoper

The Euclid Consortium is celebrating the first year of the journey of the European Space Agency’s Euclid Mission into space! Over the past 52 weeks, Euclid has been scanning the cosmos, uncovering new insights into dark matter, dark energy, and the structure of the universe. The Euclid Consortium has produced a slideshow, showcasing the key moments and discoveries from the first year in space.

The slideshow can be seen on YouTube here:

Here is a poster:

This can also found in interactive form here where you can click on each of the 52 images to see what it’s about.

P.S. The subtitle of the poster is “first year of a big journey to new physics”. There’s no guarantee that Euclid will find any new physics, rather than confirming our existing ideas, but it might.

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