Archive for Ice

Weekly Update from the Open Journal of Astrophysics 20/06/2026

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , , , , , , , , , , , , , , , on June 20, 2026 by telescoper

It’s Saturday again so it’s time for another update of activity at the Open Journal of Astrophysics. Since the last update we have published a further three papers, bringing the number in Volume 9 (2026) to 126 and the total so far published by OJAp up to 574.

I will continue to include the posts made on our Mastodon account (on Fediscience); these announcements also show the DOI for each paper.

The first paper to report this week, published on Monday 15th June, is “SN 2025adpq: A Type Ia supernova in a collisional ring formed during a major galaxy merger” by Brendan O’Connor (Carnegie Mellon University, USA) and 18 others based in the USA, Germany and Australia. The study reports the discovery of a Type Ia supernova, SN 2025adpq, within a collisional ring formed by a major galaxy merger., offset from the nucleus of the primary galaxy. It is published in the folder Astrophysics of Galaxies.

The overlay for this paper is here

You can find the officially accepted version on arXiv here and the announcement on Fediverse here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "SN 2025adpq: A Type Ia supernova in a collisional ring formed during a major galaxy merger" by Brendan O'Connor (Carnegie Mellon University, USA) and 18 others based in the USA, Germany and Australia

doi.org/10.33232/001c.163422

June 15, 2026, 8:29 am 1 boosts 1 favorites

The second paper for this week, published on Tuesday June 16th in the folder Astrophysics of Galaxies is “The Colors of Ices: Measuring ice column density through photometry” by Adam Ginsburg (U. Florida, USA) and ten others based in the USA, Germany and Spain. This study demonstrates that JWST photometry can identify and quantify interstellar ices, using new open-source models, interstellar ices, finding significant abundance in non-star-forming gas, suggesting many avenues for further research.

The overlay looks like this:

The official version of the paper can be found on arXiv here and the Fediverse announcement here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "The Colors of Ices: Measuring ice column density through photometry" by Adam Ginsburg (U. Florida, USA) and ten others based in the USA, Germany and Spain

doi.org/10.33232/001c.163469

June 16, 2026, 7:26 am 1 boosts 1 favorites

The third paper of the week, published on Wednesday 17th June in the folder Cosmology and Nongalactic Astrophysics is “The Non-Gaussian Weak-Lensing Likelihood: A Multivariate Copula Construction and Impact on Cosmological Constraints” by Veronika Oehl and Tilman Tröster (both of ETH Zurich, Switzerland). This study presents a framework for computing non-Gaussian likelihoods for correlation functions, particularly useful in large-scale weak-lensing surveys. It suggests Gaussian likelihoods are sufficient for stage-IV surveys.

The overlay for this one is here:

The final, accepted version can be found on arXiv here and the Mastodon announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "The Non-Gaussian Weak-Lensing Likelihood: A Multivariate Copula Construction and Impact on Cosmological Constraints" by Veronika Oehl and Tilman Tröster (ETH Zurich, Switzerland)

doi.org/10.33232/001c.163550

June 17, 2026, 8:30 am 1 boosts 0 favorites

The fourth and final paper of the week, also ublished on Wednesday 17th June but in the folder Astrophysics of Galaxies, is “Black Hole Feedback, Galaxy Quenching and Outflows at Cosmic Dawn: Analysis of the SEEDZ Simulations” by Lewis R. Prole (Maynooth University, Ireland) and 15 others based in Ireland, Germany, USA and UK. The study analyzes the growth and feedback effects of massive black holes in SEEDZ simulations, suggesting that black hole feedback, not nearby supernovae or gas exhaustion, limits initial growth.

The overlay is here:

The final, accepted version can be found on arXiv here and the Mastodon announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Black Hole Feedback, Galaxy Quenching and Outflows at Cosmic Dawn: Analysis of the SEEDZ Simulations" by Lewis R. Prole (Maynooth University, Ireland) and 15 others based in Ireland, Germany, USA and UK.

doi.org/10.33232/001c.163549

June 17, 2026, 8:09 am 2 boosts 1 favorites

And that concludes this week’s update. It has been a slow week on the publishing front, but the main reason is that we have a big backlog of papers accepted but waiting for the authors to put their final versions on arXiv and we can’t do anything about that! I’ll do another update next Saturday.

Euclid Updates

Posted in Euclid, The Universe and Stuff with tags , , , , , on June 11, 2024 by telescoper

I’m travelling back to Barcelona today, later than planned because I’ve had a heavy cold that I struggled to shake off and didn’t want to infect fellow passengers on the flight. While I’m in transit I thought I’d share some updates about the European Space Agency’s Euclid mission.

The first thing to share is a piece by Knud Jahnke with news about Euclid’s issue with ice in the optical system. The latest intervention has led to an improvement, but since it is a closed system ice will probably form again – though perhaps not in the same place – and further procedures will probably be necessary in future. In the meantime, though, the survey resumes.

Now for some short videos -three, to be precise – about the Early Release Observations mentioned here. I posted another one in this series here. I think the titles are self-explanatory:

And if that isn’t enough, for those of you who like simulations here is another video about the Euclid Flagship simulation described in this paper.

Euclid on Ice

Posted in Euclid, The Universe and Stuff with tags , , , , , , on March 25, 2024 by telescoper

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.

For more details, see here.

UPDATE: The latest news is that the de-icing procedure has worked better than expected! There’s even a video about the result of the process here: