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Weekly Update from the Open Journal of Astrophysics – 15/11/2025

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , , , , , , , , , , , , , , , , , , , on November 15, 2025 by telescoper

It’s Saturday again, so it’s time for the usual update of the week’s new papers at the Open Journal of Astrophysics. It has been quite a busy week. Since the last update we have published another seven papers, which brings the number in Volume 8 (2025) up to 175, and the total so far published by OJAp up to 410.

First on the menu for this week is “Dynamical friction and measurements of the splashback radius in galaxy clusters” by Talia M. O’Shea (U. Wisconsin-Madison, USA), Josh Borrow & Stephanie O’Neil (U. Pennsylvania, USA) and Mark Vogelsberger (MIT, USA). Published on Tuesday 11th November in the folder Cosmology and NonGalactic Astrophysics, this one presents a study suggesting that dynamical friction does not play a major role in reducing the radius of the splashback feature in real data compared to numerical simulations.

The overlay is here:

You can find the officially accepted version on arXiv here.

The Fediverse announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Dynamical friction and measurements of the splashback radius in galaxy clusters" by Talia M. O'Shea (U. Wisconsin-Madison, USA), Josh Borrow & Stephanie O'Neil (U. Pennsylvania, USA) and Mark Vogelsberger (MIT, USA)

doi.org/10.33232/001c.147125

November 11, 2025, 8:36 am 3 boosts 1 favorites

 

The second paper of the week is “Microlensing of lensed supernovae Zwicky & iPTF16geu: constraints on the lens galaxy mass slope and dark compact object fraction” by Nikki Arendse (Stockholm University, Sweden) and and international cast of 11 others based in Sweden, UK and France. This one was published on 11th November 2025 in the folder Astrophysics of Galaxies. It is about combining observations of two supernovae, iPTF16geu and SN Zwicky, with microlensing magnification maps to probe the properties of the lens galaxy.

The overlay is here:

 

You can find the official version of this one on arXiv here. The federated announcement on Mastodon is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Microlensing of lensed supernovae Zwicky & iPTF16geu: constraints on the lens galaxy mass slope and dark compact object fraction" by Nikki Arendse (Stockholm University, Sweden) and 11 others based in Sweden, UK and France

doi.org/10.33232/001c.147126

November 11, 2025, 8:53 am 1 boosts 1 favorites

 

Next one up is “Neutrino Constraints on Black Hole Formation in M31” by Yudai Sawa (U. Tokyo, Japan) and 11 others all based in Japan. This was published on Tuesday 11th November in the folder High-Energy Astrophysical Phenomena. It presents a calculation of the neutrino emission expected from the collapse of massive stars and its use in constraining black hole formation using neutrino detectors.

 

The overlay is here:

You can find the official accepted version on arXiv here. The fediverse announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Neutrino Constraints on Black Hole Formation in M31" by Yudai Sawa (U. Tokyo, Japan) and 11 others all based in Japan

doi.org/10.33232/001c.147127

November 11, 2025, 9:04 am 0 boosts 1 favorites

The fourth paper this week is “Redshift Drift in Relativistic N-Body Simulations” by Alexander Oestreicher (U. Southern Denmark, DK), Chris Clarkson (QMUL, UK), Julian Adamek (U. Zürich, CH) and Sofie Marie Koksbang (U. Southern Denmark, DK). This one was published on Wednesday 12th November in the folder marked Cosmology and NonGalactic Astrophysics. It presents numerical calculations of the cosmological redshift drift effect for comparison with future surveys.

The overlay is here:

 

 

You can find the official published version on arXiv here. The Fediverse announcement follows:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Redshift Drift in Relativistic N-Body Simulations" by Alexander Oestreicher (U. Southern Denmark, DK), Chris Clarkson (QMUL, UK), Julian Adamek (U. Zürich, CH) and Sofie Marie Koksbang (U. Southern Denmark, DK)

doi.org/10.33232/001c.147178

November 12, 2025, 8:35 am 1 boosts 0 favorites

 

The fifth paper for this week is “Attributing the point symmetric structure of core-collapse supernova remnant N132D to the jittering jets explosion mechanism” by Noam Soker (Technion, Haifa, Israel). This one, published on Wednesday November 12th in the folder High-Energy Astrophysical Phenomena, presents a discussion of the morphology of a supernova remnant and possible explanation for it in terms of the explosion mechanism.

The overlay is here:

 

The officially accepted version can be found on arXiv here. The Fediverse announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Attributing the point symmetric structure of core-collapse supernova remnant N132D to the jittering jets explosion mechanism" by Noam Soker (Technion, Haifa, Israel)

doi.org/10.33232/001c.147183

November 12, 2025, 8:46 am 1 boosts 0 favorites

The sixth paper to report this week is “Witnessing downsizing in the making: quiescent and breathing galaxies at the dawn of the Universe” by Emiliano Merlin (Osservatorio Astronomico di Roma, Italy) and an international cast of 20 others based in Italy, Germany, UK, USA, Switzerland, Spain and China. This one was published on Friday November 14th in the folder Astrophysics of Galaxies.

You can find the officially-accepted version on arXiv here. The fediverse announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Witnessing downsizing in the making: quiescent and breathing galaxies at the dawn of the Universe" by Emiliano Merlin (Osservatorio Astronomico di Roma, Italy) and 20 others based in Italy, Germany, UK, USA, Switzerland, Spain and China

doi.org/10.33232/001c.147267

November 14, 2025, 8:38 am 1 boosts 1 favorites

And finally (for this week) we have “Beyond No No Tension: JWST z > 10 Galaxies Push Simulations to the Limit” by Joe McCaffrey (NUI Maynooth, Ireland), Samantha Hardin & John Wise (Georgia Institute of Technology, USA) and John Regan (Maynooth). This one was also published on Friday 14th November, in the folder marked Astrophysics of Galaxies. It asks the question whether newly-discovered high redshift galaxies are consistent with simulations of galaxy formation. The overlay is here:

You can find the officially acceopted version on arXiv here. The fediverse announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Beyond No No Tension: JWST z > 10 Galaxies Push Simulations to the Limit" by Joe McCaffrey (NUI Maynooth, Ireland), Samantha Hardin & John Wise (Georgia Institute of Technology, USA) and John Regan (Maynooth)

doi.org/10.33232/001c.147278

November 14, 2025, 9:02 am 2 boosts 0 favorites

And that concludes the update for this week. There will be another next Saturday.

1 Comment »

Quantum & Answers

Posted in Maynooth, The Universe and Stuff with tags , , , on November 13, 2025 by telescoper

Returning to my office in the Science Building at Maynooth University I saw a new feature, which I initially thought was a mobile coffee shop, but which turned out to be the Quantum & Answers trailer, a mobile engagement unit, developed by IrelandQCI, and designed to bring quantum technologies to life for the general public in Ireland.

In case you weren’t aware, IrelandQCI, the ‘Building a National Quantum Communication Infrastructure for Ireland’ project incorporates integrating innovative and secure quantum devices and systems into conventional communication infrastructures. This will be done by enhancing the ESB Telecoms’ optical fibre network with an additional layer of security, all based on quantum physics, in particular quantum key distribution (QKD).

You can read more about this initiative here.

It’s on Maynooth University campus for the rest of the day so if you’re around please feel free to visit and talk about quantum encryption and the like.

Update: I popped in to get out of the rain…

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Can you make a neutral pion from two photons?

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

A neutral pion can decay into two photons. It is therefore not unreasonable to ask the question whether the reverse process – the creation of a neutral pion by colliding two photons – is physically possible and, if not, why not? It is perhaps less reasonable to ask an AI bot these questions. One of my colleagues did just that and found it said “no”, giving  the following three answers to the “why not?” question:

I particularly like the second one.

Would anyone like to offer a correct answer through the comments box?

10 Comments »

Weekly Update from the Open Journal of Astrophysics – 08/11/2025

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , , , , , , , , , , , , on November 8, 2025 by telescoper

It’s Saturday again, so it’s time for the usual update of the week’s new papers at the Open Journal of Astrophysics. Since the last update we have published another five papers, which brings the number in Volume 8 (2025) up to 168, and the total so far published by OJAp up to 403.

The first paper this week is “Maximizing Ariel’s Survey Leverage for Population-Level Studies of Exoplanets” by Nicolas B. Cowan and Ben Coull-Neveu (McGill University, Canada). This article was published in the folder Earth and Planetary Astrophysics on Tuesday 4th November 2025; it discusses various different schemes to select the mission reference sample for a notional three year transit spectroscopy survey with the European Space Agency’s Ariel mission

The overlay is here:

 

You can find the officially accepted version on arXiv here.

The Fediverse announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Maximizing Ariel’s Survey Leverage for Population-Level Studies of Exoplanets" by Nicolas B. Cowan and Ben Coull-Neveu (McGill University, Canada)

doi.org/10.33232/001c.146656

November 4, 2025, 5:08 pm 1 boosts 3 favorites

 

The second paper of the week is “A substellar flyby that shaped the orbits of the giant planets” by Garett Brown (U. Toronto at Scarborough, Canada), Renu Malhotra (U. Arizona, USA) and Hanno Rein (U. Toronto at Scarborough, Canada). This article was published on Wednesday 5th November 2025, also in the folder Earth and Planetary Astrophysics. It argues that an ancient close encounter with a substellar object offers a plausible explanation for the origin of the moderate eccentricities and inclinations of the giant planets.

The overlay is here:

You can find the official version of this one on arXiv here. The federated announcement on Mastodon is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "A substellar flyby that shaped the orbits of the giant planets" by Garett Brown (U. Toronto at Scarborough, Canada), Renu Malhotra (U. Arizona, USA) and Hanno Rein (U. Toronto at Scarborough, Canada)

doi.org/10.33232/001c.146688

November 5, 2025, 8:34 am 3 boosts 3 favorites

Next one up is “The Potential Impact of Primordial Black Holes on Exoplanet Systems” by Garett Brown (U. Toronto at Scarborough), Linda He (Harvard U., USA),  and James Unwin (U. Illinois Chicago, USA). This one was also published on Wednesday 5th November 2025, but in the folder Astrophysics of Galaxies. This one is an exploration of the possibility that primordial black holes (PBHs) in our Galaxy, might impact the orbits of exoplanets. The overlay is here:

You can find the official accepted version on arXiv here. The fediverse announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "The Potential Impact of Primordial Black Holes on Exoplanet Systems" by Garett Brown (U. Toronto at Scarborough), Linda He (Harvard U., USA), James Unwin (U. Illinois Chicago, USA)

doi.org/10.33232/001c.146689

November 5, 2025, 8:49 am 3 boosts 1 favorites

The fourth paper to report is “The Unhurried Universe: A Continued Search for Long Term Variability in ASAS-SN” by Sydney Petz, C. S. Kochanek & K. Z. Stanek (Ohio State U., USA), Benjamin J. Shappee (U. Hawaii, USA), Subo Dong (Peking University, China), J. L. Prieto (Universidad Diego Portales, Chile) and Todd A. Thompson (Ohio State U., USA). This one was also published on Wednesday November 5th 2025, but in the folder Solar and Stellar Astrophysics.  It describes the discovery and investigation of slowly-varying sources in the All Sky Automated Survey for SuperNovae (ASAS-AN) leading to the identification of 200 new variable stars. The overlay is here:

 

You can find the official published version on arXiv here. The Fediverse announcement follows:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "The Unhurried Universe: A Continued Search for Long Term Variability in ASAS-SN" by Sydney Petz, C. S. Kochanek & K. Z. Stanek (Ohio State U., USA), Benjamin J. Shappee (U. Hawaii, USA), Subo Dong (Peking University, China), J. L. Prieto (Universidad Diego Portales, Chile) and Todd A. Thompson (Ohio State U., USA)

doi.org/10.33232/001c.146690

November 5, 2025, 9:08 am 1 boosts 0 favorites

The fifth and final paper for this week is “Measuring the splashback feature: Dependence on halo properties and history” by Qiaorong S. Yu (Oxford U., UK) and 9 others based in the UK and USA. This was published on Friday 7th November 2025 in the folder Cosmology and Nongalactic Astrophysics. It discusses how the properties of “splashback” features in halo profiles relate to the halo’s assembly history (e.g. mass accretion rate and most recent merger time). The overlay is here:

The officially accepted version can be found on arXiv here. The Fediverse announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Measuring the splashback feature: Dependence on halo properties and history" by Qiaorong S. Yu (Oxford U., UK) and 9 others based in the UK and USA.

doi.org/10.33232/001c.146824

November 7, 2025, 9:12 am 0 boosts 0 favorites

That’s all the papers for this week. I’ll do another report next Saturday.

1 Comment »

Euclid’s “Tuning Fork”

Posted in Euclid, The Universe and Stuff with tags , , , on November 7, 2025 by telescoper

By way of a quick follow-up to yesterday’s post, here’s another Euclid Q1 product. This one is an updated version of the famous “Tuning Fork” representation of galaxy morphology:

Credits: Diagram: ESA/Euclid/Euclid Consortium/NASA, Diagram by J.-C. Cuillandre, L. Quilley, F. Marleau. Images alone: ESA/Euclid/Euclid Consortium/NASA, image processing by J.-C. Cuillandre, E. Bertin, G. Anselmi

You can click on the image to make it (much) bigger.

A galaxy’s structure is a sign of its formation history and the environment in which it resides. Since early on, astronomers have ordered galaxies according to their visible structure – as a basis to understanding the underlying physics: This panorama of galaxies’ structure shows the ‘classical’ morphological sequence from ellipticals (E, left) to lenticulars (S0) through spirals (S) to irregulars and dwarfs (right). The fork divides barred and unbarred spiral families: originally only SA (unbarred) and SB (barred) galaxies were arranged in a ‘tuning fork’ layout, the addition of SAB (weakly barred) galaxies as a third branch is making this term increasingly challenging to use. Lowercase letters a to d indicate progressively later spiral stages (tighter to looser arms), the trailing m (e.g., SAm) denotes Magellanic, very-late-type systems (patchy, often one-armed). The Milky Way is classified as an SBc galaxy.

Below the main sequence there are three auxiliary panels showing objects not represented in the fork: (1) spiral galaxies seen edge-on, with varying bulge-to-disk ratios and warps; (2) interacting and merging galaxies illustrating gravitationally driven morphological change; and (3) the morphological diversity of dwarf galaxies.

You can read more about this image and the other Q1 results here. You can also find an interactive version of the plot here.

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Euclid and the Dark Cloud

Posted in Art, Euclid, The Universe and Stuff with tags , , , , on November 6, 2025 by telescoper

I haven’t posted anything recently about the European Space Agency’s Euclid mission, but I can remedy that by passing on a new image with text from the accompanying press release. This is actually just one of a batch of new science results emerging from the first `Quick Release’ (Q1) data; I blogged about the first set of Q1 results here.

Incidentally, I find the picture is very reminiscent of a famous painting by James McNeill Whistler.

Image description: The focus of the image is a portion of LDN 1641, an interstellar nebula in the constellation of Orion. In this view, a deep-black background is sprinkled with a multitude of dots (stars) of different sizes and shades of bright white. Across the sea of stars, a web of fuzzy tendrils and ribbons in varying shades of orange and brown rises from the bottom of the image towards the top-right like thin coils of smoke.

Technical details: The colour image was created from NISP observations in the Y-, J- and H-bands, rendered blue, green and red, respectively.  The size of the image is 11 232 x 12 576 pixels. The jagged boundary is due to the gaps in the array of NISP’s sixteen detectors, and the way the observations were taken with small spatial offsets and rotations to create the whole image. This is a common effect in astronomical wide-field images.

Accompanying Press Release

The above view of interstellar gas and dust was captured by the European Space Agency’s Euclid space telescope. The nebula is part of a so-called dark cloud, named LDN 1641. It sits at about 1300 light-years from Earth, within a sprawling complex of dusty gas clouds where stars are being formed, in the constellation of Orion.  

This is because dust grains block visible light from stars behind them very efficiently but are much less effective at dimming near-infrared light.  

The nebula is teeming with very young stars. Some of the objects embedded in the dusty surroundings spew out material – a sign of stars being formed. The outflows appear as magenta-coloured spots and coils when zooming into the image.  

In the upper left, obstruction by dust diminishes and the view opens toward the more distant Universe with many galaxies lurking beyond the stars of our own galaxy. 

Euclid observed this region of the sky in September 2023 to fine-tune its pointing ability. For the guiding tests, the operations team required a field of view where only a few stars would be detectable in visible light; this portion of LDN 1641 proved to be the most suitable area of the sky accessible to Euclid at the time. 

The tests were successful and helped ensure that Euclid could point reliably and very precisely in the desired direction. This ability is key to delivering extremely sharp astronomical images of large patches of sky, at a fast pace. The data for this image, which is about 0.64 square degrees in size – or more than three times the area of the full Moon on the sky – were collected in just under five hours of observations. 

Euclid is surveying the sky to create the most extensive 3D map of the extragalactic Universe ever made. Its main objective is to enable scientists to pin down the mysterious nature of dark matter and dark energy. 

Yet the mission will also deliver a trove of observations of interesting regions in our galaxy, like this one, as well as countless detailed images of other galaxies, offering new avenues of investigation in many different fields of astronomy. 

In visible light this region of the sky appears mostly dark, with few stars dotting what seems to be a primarily empty background. But, by imaging the cloud with the infrared eyes of its NISP instrument, Euclid reveals a multitude of stars shining through a tapestry of dust and gas. 

2 Comments »

Trouble at Astronomy Ireland

Posted in Biographical, The Universe and Stuff with tags , , on November 5, 2025 by telescoper

I couldn’t resist passing on an unsettling news item about Astronomy Ireland, an Irish Astronomy Club described on its website in the following terms:

Astronomy Ireland is a non profit organisation and the largest national astronomy club in the world relative to population.

The news item concerned revolves around founder and chairperson David Moore (left), who has been held personally liable for multiple employment rights breaches against a former manager, Sonya Martin, at Astronomy Ireland who said she was forced to quit due to a “toxic” work environment and alleged “serious financial irregularities”.

The astronomy club and four members of its management committee, including David Moore, have been ordered to pay nearly €11,000 to the ex-employee, Sonya Martin, after she complained of constructive dismissal to the Workplace Relations Commission (WRC).

Among the allegations reported were that Mr Moore was keeping funds meant for Astronomy Ireland:

David was taking the money and pocketing it as his own income, as opposed to it going back into the society,” Ms Martin said. “The attitude changed towards myself and Ms Doyle after that,” Ms Martin said.

No doubt the money was just “resting in his account”. I mentioned this story to colleagues in the Department and none was surprised, and many (unlike myself) had known about this case for some time. I’ll keep some of the comments to myself, but one said that they gave a lecture (for free, as we academics usually do) to Astronomy Ireland which was filmed without consent. David Moore then sold DVDs of the talk. Where the profits from this went, I have no idea.

These financial shenanigans are dodgy enough but there are some truly bizarre sections of the news report. Here is one:

As the hearings continued into 2025, Mr Moore made repeated objections to being attached personally to the claim, and told Mr Dolan he had not received hearing notifications.

“Emails are unreliable,” he said. When Ms Martin’s solicitor, Mr O’Connell said the notification was sent by post too, Mr Moore said: “The post is unreliable.”

Even stranger, if not directly relevant to the case of Mr Moore, is this:

During the June 2024 hearing, Ms Martin gave evidence that Astronomy Ireland’s office landlord approached her complaining about having to clean up after the junior administrator, Mr G, who was later dismissed.

“The final straw for the landlord was that he had to clean ejaculate from the bathroom after Mr G was in there,” Ms Martin added.

Ewww…

In the interest of full disclosure, I gave a talk to Astronomy Ireland in December 2019. I don’t remember if it was filmed nor whether DVDs were sold, but given what I know now I don’t think I’ll be accepting any more speaking invitations from that organisation.

Update: it seems DVDs of my talk were made and were on sale but are no longer available. They must have sold out.

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Denario

Posted in The Universe and Stuff with tags , , , on November 3, 2025 by telescoper

I’ve been alerted (by one of the authors) to a paper in the computer science/artificial intelligence section on arXiv, called The Denario project: Deep knowledge AI agents for scientific discovery by Francisco Villaescusa-Navarro et al. The abstract follows:

We present Denario, an AI multi-agent system designed to serve as a scientific research assistant. Denario can perform many different tasks, such as generating ideas, checking the literature, developing research plans, writing and executing code, making plots, and drafting and reviewing a scientific paper. The system has a modular architecture, allowing it to handle specific tasks, such as generating an idea, or carrying out end-to-end scientific analysis using Cmbagent as a deep-research backend. In this work, we describe in detail Denario and its modules, and illustrate its capabilities by presenting multiple AI-generated papers generated by it in many different scientific disciplines such as astrophysics, biology, biophysics, biomedical informatics, chemistry, material science, mathematical physics, medicine, neuroscience and planetary science. Denario also excels at combining ideas from different disciplines, and we illustrate this by showing a paper that applies methods from quantum physics and machine learning to astrophysical data. We report the evaluations performed on these papers by domain experts, who provided both numerical scores and review-like feedback. We then highlight the strengths, weaknesses, and limitations of the current system. Finally, we discuss the ethical implications of AI-driven research and reflect on how such technology relates to the philosophy of science. We publicly release the code at this https URL. A Denario demo can also be run directly on the web at this https URL, and the full app will be deployed on the cloud.

arXiv:2510.26887

Here’s a random picture from the paper:

I haven’t had time to read the paper yet – it’s 270 pages long – but I’m sure it will provoke strong reactions both in favour and against the idea of an AI research assistant. Comments are welcome through the box below.

P.S. The name Denario appears to be derived from the Latin “denarius”, a coin roughly equivalent to a day’s pay for a skilled worker in the days of the Roman Empire. More amusingly, “denarius” is the origin of the Polari word “dinarly”, meaning “money”. If I get time I must generate a Polari version of this manuscript.

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Weekly Update from the Open Journal of Astrophysics – 01/11/2025

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , on November 1, 2025 by telescoper

It’s time once again for the usual Saturday update of the week’s new papers at the Open Journal of Astrophysics (although a bit later in the day than usual). Since the last update we have published another two papers, which brings the number in Volume 8 (2025) up to 163, and the total so far published by OJAp up to 398.

The first paper this week is “Instability and vertical eccentricity variation in global hydrodynamic disk simulations” by Janosz W Dewberry (U. Mass. Amherst, USA), Henrik N. Latter and Gordon I. Ogilvie (U. Cambridge, UK) and Sebastien Fromang (U. Paris Saclay, France). This article was published in the folder Solar and Stellar Astrophysics on Tuesday 28th October 2025; it discusses the instabilities and eccentricity variations generated in numerical hydrodynamic simulations of accretion disks.

The overlay is here:

You can find the officially accepted version on arXiv here.

The Fediverse announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Instability and vertical eccentricity variation in global hydrodynamic disk simulations" by Janosz W Dewberry (U. Mass. Amherst, USA), Henrik N Latter and Gordon I Ogilvie (U. Cambridge, UK) & Sebastien Fromang (U. Paris Saclay, France)

doi.org/10.33232/001c.146332

October 28, 2025, 9:43 am 2 boosts 0 favorites

The second (and last) paper of the week is “Fast X-ray Transient Detection with AXIS: application to Magnetar Giant Flares” by Michela Negro (Louisiana State University, USA) and 8 others based in the USA and Canada. This one was also published on Tuesday 28th October, but in the folder High-Energy Astrophysical Phenomena. It presents a feasibility study of detecting Magnetar Giant Flares with the Advanced X-ray Imaging Satellite (AXIS). The overlay is here:

You can find the official version of this one on arXiv here. The announcement on Mastodon is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Fast X-ray Transient Detection with AXIS: application to Magnetar Giant Flares" by Michela Negro (Louisiana State University, USA) and 8 others based in the USA and Canada

doi.org/10.33232/001c.146360

October 28, 2025, 10:02 am 1 boosts 1 favorites

It being a relatively slow week we didn’t reach the 400 mark as I thought we might, but we will probably get there next week. After 10 months of the year 2025, in which we have published 163 papers, a rough projection for the 2025 total is 195. We do have some extra papers up our sleeve, however, so we might well reach 200 for the year. We will find out soon enough!

1 Comment »

On the Evidence for Supersymmetry from CMS…

Posted in The Universe and Stuff with tags , , , , on October 27, 2025 by telescoper

Every now and again I look at the latest particle physics literature on arXiv to see what’s going on. The other day I saw a preprint there which gives a review of the latest results on supersymmetry from the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider at CERN. I should explain that, in experimental particle physics, “compact” means “fucking enormous”.

Anyway, the abstract of the paper reads:

The Run 2 data-taking period of the CERN Large Hadron Collider during years 2015-2018 provided about 140 fb-1 of proton-proton collisions at 13 TeV, offering an unprecedented opportunity to explore supersymmetry (SUSY) across a wide range of experimental signatures. CMS responded with a broad and diverse search program, carrying out dozens of analyses that probed a multitude of final states and systematically explored different regions of the SUSY parameter space. No significant deviations from standard model predictions were observed, and the results were used for constraining the SUSY landscape. In this review, I provide a comprehensive account of the CMS Run 2 SUSY program, covering its strategy, targeted models, and analysis methods. I then present the full set of searches and conclude with their combined impact through simplified model and phenomenological MSSM interpretations.

arXiv:2510.17971

Here is one of the pretty pictures from the review. This one shows the constraints on the masses of any supersymmetric counterparts of the electroweak gauge bosons.

To summarize the evidence for supersymmetry from CMS, there is none, nil, nought, nada, zero, zilch, zip, sweet Fanny Adams, bugger-all and diddly-squat. I hope this clarifies the situation.

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