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Weekly Update from the Open Journal of Astrophysics 18/07/2026

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags 3I/Atlas, Active galactic nuclei, arXiv:2510.13803v2, arXiv:2511.13669v3, arXiv:2512.05050v2, arXiv:2512.09020v2, arXiv:2603.16991v2, arXiv:2604.19463v2, Astrophysics of Galaxies, biased galaxy formation, Circumgalactic Medium, cosmological parameters, cosmological simulations, Cosmology, Cosmology and NonGalactic Astrophysics, covariance matrices, Dark Energy Spectroscopic Instrument, Density reconstruction, DESI, Diamond Open Access, Diamond Open Access Publishing, Earth and Planetary Astrophysics, equivalence principle, galaxy clusters, galaxy haloes, interstellar comets, line-of-sight shear, LSST Dark Energy Science Collaboration, Lyman-alpha, Open Access, Open Access Publishing., protoclusters, SLACS, statistical cosmology, strong gravitational lensing on July 18, 2026 by telescoper

It’s time once more for another Saturday update of activity at the Open Journal of Astrophysics. Since the last update we have published a further six papers, bringing the number in Volume 9 (2026) to 151 and the total so far published by OJAp up to 599.

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 Tuesday 14th July, is “On combining estimated and analytic covariance matrices” by Alan Heavens (Imperial College London, UK), Lorne Whiteway (University College, London, UK) and Elena Sellentin (Leiden University, The Netherlands). This article, published in the folder Cosmology and Nongalactic Astrophysics, presents an accurate approximation for the combined likelihood function in cosmological data analysis, improving upon previous methods by better representing the heavy tails of the true distribution.

The overlay for this paper is here

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

The second paper for this week, also published on Tuesday 14th July in the folder Cosmology and Nongalactic Astrophysics is: “Line-of-sight shear in SLACS strong lenses II: validation tests with an extended sample” by Natalie B. Hogg (U. Cambridge, UK), Daniel P. Johnson (Université de Montpellier, France), Anowar J. Shajib (U. Chicago, USA) and Julien Larena (Montpellier). The study described in this paper models 27 additional gravitational lenses, finding a significant fraction with unexpectedly large line-of-sight shears. Factors like redshift, filter, and signal-to-noise ratio don’t significantly affect shear magnitudes.

The overlay looks like this:

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

The third paper of the week, published on Wednesday 15th July, again in the folder Cosmology and Nongalactic Astrophysics “Investigating the Dark Energy Constraint from Strongly Lensed AGN at LSST-Scale” by Sydney Erickson (Stanford University, USA) and 13 others on behalf of The LSST Dark Energy Science Collaboration. The study uses a new technique to analyze a large sample of lensed Active Galactic Nuclei, providing an independent probe of dark energy and improving constraints on the Universe’s expansion.

The overlay for this one is here:

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

The fourth paper of the week, also published on Wednesday 15th July but in the folder Earth and Planetary Astrophysics is “University of Hawaii 88-inch Telescope Observations of the Interstellar Comet 3I/ATLAS: Spectrophotometric Blue-Sensitive Spectral Time Series Spanning Two Months from Discovery” by W. B. Hoogendam (University of Hawaii, USA) and 24 others from around the world. The study presents observations of the third interstellar object, 3I/ATLAS, using the SuperNova Integral Field Spectrograph, revealing its properties and comparing it to bodies in our solar system.

The overlay for this one is here:

You can read the final version of this one on arXiv here and the Mastodon announcement is here:

The fifth paper of the week, published on Friday 17th July in the folder Astrophysics of Galaxies, is “The birth of the intracluster medium: the evolution of multiphase gas and Lyman-α haloes in a z~3 simulated protocluster” by Jake S. Bennett (Harvard Smithsonian CfA, USA), Aaron Smith (U. Nottingham, UK), Fabrizio Arrigoni-Battaia (MPA Garching, Germany), Debora Sijacki (U. Cambridge, UK) , Cassandra Lochhaas (CfA) and Lars Hernquist (CfA). This study uses a cosmological simulation to explore the transition from complex galactic haloes to mature galaxy clusters, focusing on gas distribution, ionisation, and emission changes during this evolution.

The overlay for this one is here:

You can read the final version of this one on arXiv here and the Mastodon announcement is here:

The sixth and final paper paper of this week is “”Density reconstruction from biased tracers: Testing the equivalence principle through consistency relations” by Lawrence Dam and Omar Darwish (Université de Genève, Switzerland). This was published on Friday 17th July in the folder Cosmology and Nongalactic Astrophysics. It proposes using quadratic estimators to test the weak equivalence principle on cosmological scales, offering a practical alternative to the conventional bispectrum approach.

The overlay for this one is here:

You can find the final accepted version on arXiv here and the Mastodon announcement is here:

As you can see we have now published over 150 papers this year and are just one shy of 600 in total. I expect we’ll pass that milestone next week. I’ll do another update next Saturday.

The Coherence Principle

Posted in The Universe and Stuff with tags arXiv:2606.18491v1, Bayesian Model Selection, Cosmology, Ed Jaynes, Prior Probability on July 14, 2026 by telescoper

Back into the swing of things in Maynooth, getting ready for the repeat examinations that start next month, I realized that I had forgotten to pass on an interesting paper that I found out about a few weeks ago but was reminded of while in London so I’m remedying my omission now. The title is The Coherence Principle: A Falsifiable Prior for Model Selection from the Grammar of Theories by Raul Jimenez, Carlos Peña Garay, Fergus Simpson, and Licia Verde. It addresses the issue of how to assign prior probabilities. We know how to do this in cases where the models concerned belong to a family differentiated by relatively simple parameters (as is the case in the standard cosmological framework), but for more complex differences the appropriate prior is difficult to choose. I see the paper as an attempt to extend the work of Ed Jaynes, though I’m not sure the authors see it quite in those terms!

Here is the abstract:

Bayesian model selection in cosmology and particle physics is often performed where posterior odds inherit a strong, often unacknowledged dependence on the prior assigned to competing models. Standard responses — reference priors, hierarchical priors, or appeals to naturalness — ignore relevant theoretical knowledge or rely on criteria hard to define operationally. We propose the Coherence Principle: a reproducible prescription for assigning model priors according to compatibility with the validated structure of an existing theory. This structure, grammar, includes symmetries, conservation laws, locality, Lorentz invariance, and universality patterns. Unmotivated violations of these rules incur a coherence cost, converted into a prior weight through a maximum-entropy exponential form controlled by one calibratable parameter α. The resulting prior is distinct from both the Bayesian Occam factor and naturalness: it penalizes not parameter volume or fine tuning, but departures from validated theoretical grammar. We illustrate the principle with examples from cosmology and fundamental physics: neutrino mass mechanisms, dark energy and modified gravity, inflation, beyond-Standard-Model sectors, and hierarchical astrophysical inference. We test it also on four historical cases — general relativity, Pauli’s neutrino, parity violation, and special relativity — where evidential and theoretical contexts can be reconstructed. These examples show that it favors the historically successful choice when the proper grammar is defined in the correct domain and time. The Coherence Principle makes explicit a common but usually tacit part of physical reasoning: trust in validated structural rules. It turns this judgment into a transparent, testable, and overrulable component of Bayesian inference, leaving empirical likelihoods free to dominate when data are sufficiently constraining.

arXiv:2606.18491v1

Weekly Update from the Open Journal of Astrophysics 11/07/2026

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags arXiv:2501.16292v3, arXiv:2511.00229v2, arXiv:2512.03230v2, arXiv:2512.09075v2, arXiv:2512.18786v3, arXiv:2512.24936v3, arXiv:2602.16128v3, arXiv:2603.01934v2, arXiv:2606.01496v2, Astrophysics of Galaxies, Circumgalactic Medium, cosmic rays, cosmological parameters, Cosmology, Cosmology and NonGalactic Astrophysics, Cygnus X-3, DESI, Diamond Open Access, Diamond Open Access Publishing, fast radio bursts, Forbush decreases, FRB 20240114A, Galaxy shapes, General Relativistic Entropic Acceleration, Geomagnetic Storms, GREA, High-Energy Astrophysical Phenomena, Instrumentation and Methods for Astrophysics, line-of-sight shear, magnetohydrodynamic turbulence, Open Access, Open Access Publishing., peculiar velocities, pevatron, quasar variability, quasars, SLACS, strong gravitational lensing on July 11, 2026 by telescoper

Back home to Maynooth, just in time for another Saturday update of activity at the Open Journal of Astrophysics. Since the last update we have published a further nine papers, bringing the number in Volume 9 (2026) to 145 and the total so far published by OJAp up to 593.

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 Tuesday 7th July, is “The Information Content of Quasar Variability Light Curves: How Well Can we Infer Stochastic Model Parameters?” by Brendon Brewer (U. Auckland, NZ), Geraint F. Lewis (U. Sydney, AU), Xiang Yu & Yuan Li (Auckland). Published in the folder Astrophysics of Galaxies, this study suggests that quasar variability studies should focus on the short term volatility parameter, as it’s more informative than the variability timescale. Volatility decreases with redshift suggesting intrinsic effects.

The overlay for this paper is here

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

The second paper for this week, also published on Tuesday 7th July, but in the folder High-Energy Astrophysical Phenomena, is “Cygnus X-3 as a PeVatron and the LHAASO 2025 data” by Michael Kachelriess & E. Lammert (NTNU, Trondheim, Norway). This paper suggests that the high-mass X-ray binary Cygnus X-3 can accelerate cosmic rays beyond PeV energies, contributing to a photon flux peaking around PeV energies.

The overlay looks like this:

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

The third paper of the week, also published on Tuesday 7th July, but in the folder Cosmology and Nongalactic Astrophysics is “The DESI DR1 Peculiar Velocity Survey: growth rate measurements from galaxy and momentum correlation functions” by Ryan J Turner (Swinburne Institute of Technology, Australia) and 63 others from around the world. This paper analyzes local peculiar velocity and galaxy density fields to test cosmological models of gravity, finding results consistent with predictions from Planck+ΛCDM cosmology and general relativity.

The overlay for this one is here:

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

The fourth paper of the week, published on Wednesday 8th July in the folder Instrumentation and Methods for Astrophysics , is “Morphological Fingerprints of Forbush Decreases and Their Relation to Geomagnetic Storm Severity” by Juan Diego Perez Navarro and David Sierra Porta (Universidad Tecnológica de Bolívar, Colombia). This article introduces a graph-based method to analyze Forbush decreases (FDs), transient depressions in cosmic-ray flux, and uses network signatures to predict geomagnetic storm intensity.

The overlay for this one is here:

You can read the final version of this one on arXiv here and the Mastodon announcement is here:

The fifth paper of the week, also published on Wednesday 8th July but in the folder Astrophysics of Galaxies, is “On the connection between galaxy orientation and halo absorption properties” by Rohan Venkat, Soo May Wee, and Hsiao-Wen Chen (U. Chicago, USA). This article investigates the azimuthal dependence of metal-line absorption in the circumgalactic medium of 87 isolated galaxies. The results show no significant correlation between absorption strength and azimuthal angle.

The overlay for this one is here:

You can read the final version of this one on arXiv here and the Mastodon announcement is here:

The sixth paper of this week is “Searching for Periodicity in FRB 20240114A” by Jonathan I Katz (Washington U., USA). This was published on Thursday 9th July in the folder High-Energy Astrophysical Phenomena. The study described in this paper observed FRB 20240114A, an active Fast Radio Burst, but found no significant periodicity in its bursts, contradicting magnetar models predictions.

The overlay for this one is here:

You can find the final accepted version on arXiv here and the Mastodon announcement is here:

The seventh article for this week is “Multiphase gas in Circumgalactic cloud complexes: Insights from kiloparsec-scale Magnetohydrodynamic Turbulence Simulations” by Rajsekhar Mohapatra (Princeton U., USA), Alankar Dutta (MPA Garching, Germany) and Prateek Sharma (Indian Institute of Science, Bangalore). This -paper was also published on Thursday 9th July, in the folder Astrophysics of Galaxies. This paper uses high-resolution simulations to investigate the mass distribution of the circumgalactic medium (CGM), a diffuse gas surrounding a galaxy’s halo with small-scale clumps of cold gas forming in quiescent regions.

The overlay for this one is here:

You can find the final accepted version of this one on arXiv here and the Mastodon announcement is here:

The (penultimate) eighth article for this week is “Line-of-sight shear in SLACS strong lenses I: shear and mass model parametrisations” by Natalie B. Hogg (U. Cambridge, UK), Daniel Johnson (U. Montpellier, France), Anowar J. Shajib (U. Chicago, USA) and Julien Larena (Montpellier). This was also published on Thursday 9th July, but in the folder Cosmology and Nongalactic Astrophysics. This article studies models of 23 strong gravitational lenses to measure line-of-sight shear for the first time, providing potential new constraints on cosmological parameters.

The overlay for this one is here:

You can find the final accepted version on arXiv here and the Mastodon announcement is here:

The ninth and last article for this week is “Current and future constraints on the expansion history of the GREA model” by Irene Graziotti (INAF-Osservatorio Astronomico di Capodimonte, Italy), Chiara De Leo (Sapienza University of Rome, Italy) and Matteo Martinelli (INAF-Osservatorio Astronomico di Roma, Italy). This study explores the General Relativistic Entropic Acceleration (GREA) framework, comparing it to the standard description of the universe. Current data favors the standard model, but GREA remains competitive.

The overlay for this one is here:

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

As you can see, it has been a bumper week, especially when you consider that there was no arXiv mailing om Monday July 6th owing to the July 4th holiday in the USA. I should have known this would happen while I was travelling!

Invisible Rainbows, by Alfredo Carpineti

Posted in Biographical, LGBTQ+, Literature with tags Alfredi Carpineti, astronomy, Astrophysics, Cosmology, Invisible Rainbows on July 8, 2026 by telescoper

Today has been a very frustrating day from the point of view of travel – apparently it’s too hot for trains to function – but at least that gave me time to read the book Invisible Rainbows by Dr Alfredo Carpineti (left). This is an engaging and nicely written tour of what we know (and don’t know) about the Universe organized by wavelength of electromagnetic radiation, from radio through microwaves and infrared, to ultraviolet and X-rays to gamma rays. All the wavebands outside the range of human perception, in fact.

What makes this book different from others that have taken the same general approach is that he builds that fairly conventional narrative around conversations with LGBTQIA+ scientists to demonstrate how diverse perspectives have contributed to the advancement of astronomy, astrophysics and cosmology.

There are even a couple of quotes from yours truly, but it’s not just for vanity’s sake that I’m very happy to see this book published. It’s very nicely written and offers a very new perspective on science as a human endeavour. This definitely the first astrophysics book I’ve seen with a dedication “For all the queer kids reaching for the stars”. I guess I was one of those once! The book is at times humorous, even cheeky, but always driven by a passion for astrophysics and the celebration of human diversity. I wish I had I time to read it before Pride Month, but I’m nevertheless very proud to have featured even in a tiny way in such a delightful book.

1 Comment »

Weekly Update from the Open Journal of Astrophysics 04/07/2026

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags accretion disks, arXiv:2411.15112v4, arXiv:2505.12671v2, arXiv:2507.17742v2, arXiv:2511.07066v2, arXiv:2512.10613v2, arXiv:2605.14065v2, arXiv:2606.11293v2, Astrophysics of Galaxies, baryon acoustic oscillations, baryon feedback, black hole mergers, black holes, cosmic inflation, Cosmic Microwave Background, Cosmology, Cosmology and NonGalactic Astrophysics, Diamond Open Access, Diamond Open Access Publishing, fast radio bursts, Fermi Bubbles, gamma-ray astronomy, High-Energy Astrophysical Phenomena, hypervelocity runaways, magnetic fields, magnetic turbulence, Open Access, Open Access Publishing., Plasma Physics, Solar and Stellar Astrophysics, thermonuclear supernovae on July 4, 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 seven papers, bringing the number in Volume 9 (2026) to 136 and the total so far published by OJAp up to 584.

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 29th June, is “Analysis and implications of the spatio-spectral morphology of the Fermi Bubbles” by Ami Tank (Indian Institute of Technology) and Roland Crocker & Mark R. Krumholz (Australian National University). Published in the folder High-Energy Astrophysical Phenomena, this paper presents an analysis of the gamma-ray structures of Fermi Bubbles in the Milky Way using a decade of data. The research suggests either hadronic or leptonic processes can explain the data.

The overlay for this paper is here

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

The second paper for this week, also published on Monday 29th June, but in the folder Cosmology and Nongalactic Astrophysics, is “A first measurement of baryonic feedback with Fast Radio Bursts” by Robert Reischke (Universität Bonn, Germany) and Steffen Hagstotz (Ludwig-Maximilians Universität München, Germany). This paper argues that Fast Radio Bursts (FRBs) provide a new method to trace baryon distribution and feedback in the cosmos, offering insights into matter distribution and rejecting no-feedback scenarios with high confidence.

The overlay looks like this:

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

The third paper of the week, published on Tuesday 30th June in the folder High-Energy Astrophysical Phenomena, is “Idealized Global Models of Accretion Disks with Strong Toroidal Magnetic Fields” by Minghao Guo & Eliot Quataert (Princeton U., USA), Jonathan Squire (U. Otago, NZ), Philip F. Hopkins (Caltech, USA) and James M. Stone (Princeton). This study uses global magnetohydrodynamic simulations to explore the behavior of idealized accretion disks with strong toroidal magnetic fields, finding that these systems maintain a moderately strong mean azimuthal field.

The overlay for this one is here:

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

The fourth paper of the week, published on Tuesday 30th June in the folder High-Energy Astrophysical Phenomena, is “On the effective spin-mass ratio relation of binary black hole mergers that evolved in isolation” by Sambaran Banerjee (Helmholtz-Instituts für Strahlen und Kernphysik, Germany) and Aleksandra Olejak (MPA Garching, Germany). This study explores mechanisms of binary black hole mergers and finds that certain spin and mass ratio trends can be naturally explained by isolated binary evolution. The overlay for this one is here:

You can read the final version of this one on arXiv here and the Mastodon announcement is here:

The fifth paper of the week, also published on Tuesday 30th June but in the folder Solar and Stellar Astrophysics is “A systematic survey for hypervelocity runaways from thermonuclear supernovae” by Kareem El-Badry (Caltech, USA), and 18 others based in the USA, Germany, Austria and the UK. This paper presents a systematic survey of hypervelocity runaways, resulting from white dwarf explosions in binary systems. The findings suggest a diversity of remnant masses, ages, and heating mechanisms, challenging theoretical models.

The overlay for this one is here:

You can read the final version of this one on arXiv here and the Mastodon announcement is here:

The sixth and penultimate paper of this week is “Boris and Exponential Integrators in the Theory of Particles Interacting with Magnetic Turbulence” by Andreas Shalchi (U. Manitoba, Canada). This was published on Wednesday 1st July, in the folder Solar and Stellar Astrophysics (it is posted in the plasma physics section of aXiv but cross-listed in solar and stellar astrophysics). The study compares the Rodrigues and Boris integrators in test-particle simulations of charged particles interacting with magnetic fields, finding both methods yield similar results.

The overlay for this one is here:

You can find the final accepted version on arXiv here and the Mastodon announcement is here:

The seventh and final paper for this week is “Inflation at the End of 2025: Constraints on $r$ and $n_S$ using the Latest CMB and BAO Data” by Lennart Balkenhol (Institut d’Astrophysique de Paris, France) and 12 others based in France, Italy, Switzerland, UK, USA and Australia. This was also published on Wednesday 1st July, in the folder Cosmology and Nongalactic Astrophysics. This study presents constraints on parameters of inflationary models in cosmology, using the latest cosmic microwave background and baryon acoustic oscillation data. The findings help differentiate between inflation models.

The overlay for this one is here:

You can find the final accepted version of this one on arXiv here and the Mastodon announcement is here:

And that concludes this week’s update. We’re starting to catch up on the backlog generated in June. At just past the halfway point of the year, which is where we are, we’re on 136 papers, which suggests a total around 272 for the year.

1 Comment »

Structures on Gigaparsec Scales?

Posted in Astrohype, The Universe and Stuff with tags arXiv:2607.01172, cosmological principle, Cosmology, DESI DR1, Francesco Sylos-Labini, galaxy surveys, Marco Galoppo, Till Sawala on July 2, 2026 by telescoper

The latest in a sequence of claims of very large scale structures in the distribution that violate the cosmological principle emerged a week or so ago with a paper in Nature. The paper is behind a paywall but here is the abstract:

I’ve been nudged a few times by various people to comment on that but I’ve been busy recently and didn’t have time to look at the paper in detail. I had a quick look today and the thing that immediately struck me was that I didn’t understand the mock catalogues they used to compare the ΛCDM model with the observations. I still don’t understand that but I’ve stopped worrying about it because today I received a preprint (not behind a paywall, but on arXiv) from Till Sawala with the title The local galaxy distribution does not violate the cosmological principle and the (rather devastating) abstract:

The cosmological principle, which states that the Universe is statistically homogeneous and isotropic on sufficiently large scales, is a foundational assumption of the standard cosmological model. A recent analysis of DESI DR1 galaxy samples reported coherent anisotropic features in the local galaxy distribution extending to gigaparsec scales. If correct, this result would directly contradict the cosmological principle and motivate inhomogeneous cosmologies. Here I analyse the same data and compare them with galaxy distributions predicted by the FLAMINGO cosmological hydrodynamic simulation, performed in the standard ΛCDM paradigm. I show that the apparent anomaly disappears when the correct comoving distance scale is used. I also show that, rather than violating the cosmological principle, the observed structures are consistent with those expected in a ΛCDM Universe.

Here’s Figure 9 of the Sawala paper.

It seems that the authors of the Nature paper, Francesco Sylos Labini and Marco Galoppo, misinterpreted the distances of galaxies in the DESI DR1 sample in a way which boils down to an error of a factor (1+z)/h, where z is the redshift and h represents the Hubble constant. This hugely increases the scale and distorts the pattern of galaxy clustering. Using the correct comoving distance the measured structures are completely consistent with ΛCDM.

Oops!

P.S. I’ve stopped worrying about the mock surveys…

3 Comments »

A DESI Milestone

Posted in Biographical, The Universe and Stuff with tags Cosmic Web, Cosmology, Dark Energy, Dark Energy Spectroscopic Instrument, DESI, Galaxy redshift surveys on April 29, 2026 by telescoper

Yesterday the Open Journal of Astrophysics published a paper by Porredon et al which will feature in the usual Saturday round-up. That paper, which is based on the First Data Release from the Dark Energy Spectroscopic Instrument (DESI) reminded me that I should mention that DESI recently reached an amazing milestone – it has now mapped the positions and redshifts of 47 million galaxies and quasars! There is a full press-release about this achievement here.

Here’s a little video showing how the survey works:

There are more videos and other graphics in the press release.

Here’s a nice picture showing a thin slice through the full survey that reveals the characteristic “cosmic web” of the large-scale structure of the Universe in all its glory:

This progress is great, but it really makes me feel old. Forty years ago, in 1986, I had just started my PhD. The state-of-the-art galaxy redshift survey slice then is shown in this plot, from de Lapparent et al 1986 (ApJLett 302, L1), one of the first papers I read as a research student (I got it in 1985 as a preprint), which contains just 1,100 galaxies:

It is worth mentioning that although DESI has now covered its original target area, it will continue until 2028. You can never have too many galaxy redshifts!

4 Comments »

Weekly Update from the Open Journal of Astrophysics – 07/03/2026

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags arXiv:2508.16773v3, arXiv:2512.12644v2, back-reaction, Cosmology, Diamond Open Access, Diamond Open Access Publishing, Instrumentation and Methods for Astrophysics, Lunar Surface Electromagnetics Experiment, LuSEE-Night, Open Access, Open Access Publishing., Open Journal of Astrophysics on March 7, 2026 by telescoper

It’s Saturday once more, so it’s time for another update of activity at the Open Journal of Astrophysics. After a bumper week last week, this week has been slower on the publication side. Since the last update we have published a further two papers, bringing the number in Volume 9 (2026) to 47 and the total so far published by OJAp up to 495.

I will continue to include the posts made on our Mastodon account (on Fediscience) to encourage you to visit it. Mastodon is a really excellent service, and a more than adequate replacement for X/Twitter (which nobody should be using); these announcements also show the DOI for each paper.

The first paper to report is “Comments on “Little ado about everything” by A. Lapi et al. and on cosmological back-reaction” by Julian Adamek (Universität Zürich, Switzerland). This was published on Wednesday 4th March 2026 in the folder Cosmology and Nongalactic Astrophysics. The author critiques A. Lapi et al.’s ηCDM model, arguing that their claim of accelerated universe expansion driven by density field fluctuations is implausible.

The overlay, which features one of the large library of stock images provided by Scholastica because there are no pictures in the paper, is here:

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

The second (and last) paper for this week is “Linear map-making with LuSEE-Night” by Hugo Camacho (Brookhaven National Laboratory, USA) and 34 others based in the USA, France, and the Netherlands. This was published on Thursday 5th March in the folder Instrumentation and Methods for Astrophysics. The paper discusses LuSEE-Night (the Lunar Surface Electromagnetics Experiment), a proposed lunar radio telescope using four antennas to map the sub-50 MHz sky with a 5-degree resolution, using the Wiener filter algorithm to manage systematic effects.

The overlay for this one is here:

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

That concludes this week’s (brief) update. Based on the number of papers accepted and waiting to be published it is likely we will pass 50 for the year and 500 in total by next week.

P.S. Thank you once again to the many people who have responded to the latest call for editors. I’ve been sending out invitations and getting people onboard as quickly as I can, but I still have a number to get to so please bear with me!

1 Comment »

Weekly Update from the Open Journal of Astrophysics – 21/02/2026

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags AM Canum Venaticorum, AM CVn binary stars, arXiv:2506.09533v2, arXiv:2508.13296v4, arXiv:2509.22779v4, arXiv:2509.23278v2, arXiv:2601.00945v2, arXiv:2601.08524v2, astrophysical jets, Astrophysics of Galaxies, binary stars, Cosmic Dawn, Cosmic Velocities, Cosmology, Cosmology and NonGalactic Astrophysics, Diamond Open Access, Diamond Open Access Publishing, DIPLODOCUS, galaxy formation, galaxy haloes, gamma-ray burst, GRB 250702B, Great Attractor, High-Energy Astrophysical Phenomena, Instrumentation and Methods for Astrophysics, large-scale structure of the Universe, Open Access, Open Access Publishing., Open Journal of Astrophysics, Solar and Stellar Astrophysics, Square Kilometre Array, Square Kilometre Array Observatory, Ultra-long Gamma-ray burst on February 21, 2026 by telescoper

It’s Saturday once more so time for another update of activity at the Open Journal of Astrophysics. Since the last update we have published a further six papers, bringing the number in Volume 9 (2026) to 36 and the total so far published by OJAp up to 484.

The first paper to report this week is “SKA-Low simulations for a cosmic dawn/epoch of reionisation deep field” by Anna Bonaldi, Philippa Hartley, Simon Purser & Omkar Bait (SKAO, UK), Eunseong Lee (U. Manchester, UK), Robert Braun (SKAO), Florent Mertens (Sorbonne Université, France), Andrea Bracco (Osservatorio Astrofisico di Arcetri, IT), Wendy Williams (SKAO) and Cath Trott (Curtin U., Australia). This paper presents a simulation of an SKA-Low cosmic dawn/epoch of reionisation observation to advance foreground-mitigation approaches: the simulation includes various sky components and modelled errors, allowing for efficacy assessment. It was published on Monday 16th February in the folder Cosmology and Nongalactic Astrophysics.

The overlay is here:

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

The second paper is “V717 Andromedae: An Active Low Mass Ratio Contact Binary” by Surjit S. Wadhwa (Western Sydney U. Australia), Marko Grozdanovic (Astronomical Observatory Belgrade, Serbia), and Nicholas F.H Tothill, Miroslav D. Filipovic, Ain Y. De Horta (Western Sydney U.). This was also published on Monday 1th February, but in the folder Solar and Stellar Astrophysics. The article discusses the contact binary V717 Andromedae, an extreme low mass ratio system with high inclination and moderate contact, showing signs of chromospheric activity but stable and not a merger candidate

The overlay for this one is here:

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

Next, published on Tuesday 17th February in the folder High-Energy Astrophysical Phenomena, is “DIPLODOCUS II: Implementation of transport equations and test cases relevant to micro-scale physics of jetted astrophysical sources” by Christopher N Everett (Oxford U., UK), Marc Klinger-Plaisier (U. Amsterdam, NL) and Garret Cotter (Oxford). This one discusses further applications of DIPLODOCUS, which is a framework developed for particle distribution transport, with its numerical implementation detailed in Diplodocus.jl. It uses a new sampling technique and is tested on micro-scale physical effects. The first paper in the series can be found here.

The overlay is here:

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

The fourth paper this week, also published on Tuesday 17th February, but in the folder Cosmology and Nongalactic Astrophysics is “Revisiting the Great Attractor: The Local Group’s streamline trajectory, cosmic velocity and dynamical fate” by Richard Stiskalek (Oxford U., UK), Harry Desmond (U. Portsmouth, UK), Stuart McAlpine (Stockholm, SE), Guilhem Lavaux (Sorbonne Université, FR), Jens Jasche (Stockholm) and Michael J. Hudson (U. Waterloo, Canada). This paper revisits the so-called “Great Attractor” concept, finding that it doesn’t dominate the Local Group’s cosmic velocity; multiple structures contribute to the motion, with no single attractor accounting for the flow.

Here is the overlay:

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

The fifth paper this week, is “JWST observations of three long-period AM CVn binaries: detection of the donors and hints of magnetically truncated disks” by Kareem El-Badry (Caltech), Antonio C. Rodriguez (CfA Harvard), Matthew J. Green (U. Oklahoma) & Kevin B. Burdge (MIT); all based in the USA. The article was published on Thursday 19th February 2026 in the folder Solar and Stellar Astrophysics. The paper describes high-cadence infrared spectroscopy used to analyze three long-period, eclipsing AM CVn (AM Canum Venaticorum) binaries; findings suggest the presence of magnetized white dwarf accretors, with surface magnetic fields of 30-100 kG.

The overlay is here:

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

Finally for this week we have “Ultra-long Gamma-ray Bursts from Micro-Tidal Disruption Events: The Case of GRB 250702B” by Paz Beniamini (Open University, IL), Hagai B. Perets (Technion, IL) and Jonathan Granot (Open University, IL); all based in Israel. The paper was published on Friday 18th February 2026 in the folder High-Energy Astrophysical Phenomena.

The overlay is here:

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

And that concludes this week’s update. I will do another next Saturday, by which time I expect we will have published a similar number of papers to this week.

1 Comment »

Weekly Update from the Open Journal of Astrophysics – 14/02/2026

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags arXiv:2507.20190v2, arXiv:2508.00611v3, arXiv:2509.02316v4, arXiv:2510.00440v3, arXiv:2511.01506v2, arXiv:2511.14912v2, Astrophysics of Galaxies, cosmological inference, Cosmology, Cosmology and NonGalactic Astrophysics, Diamond Open Access, Diamond Open Access Publishing, entropy, Faraday Depolarization, Forbush decreases, Fractal Markers, galaxy formation, galaxy haloes, Instrumentation and Methods for Astrophysics, Interstellar Medium, large-scale structure of the Universe, LOFAR, Nebular Emission, Open Access, Open Access Publishing., Open Journal of Astrophysics, Power spectrum, self-interacting dark matter, stellar accretion, supermassive black holes, The Open Journal of Astrophysics on February 14, 2026 by telescoper

It’s Saturday once more so time for another update of activity at the Open Journal of Astrophysics. Since the last update we have published a further six papers, bringing the number in Volume 9 (2026) to 30 and the total so far published by OJAp up to 478.

The first paper to report this week is “Faraday Depolarization Study of a Radio Galaxy Using LOFAR Two-metre Sky Survey: Data Release 2” by Samantha Sneha Paul and Abhik Ghosh (Banwarilal Bhalotia College, India). This was published on Tuesday February 10th in the folder Cosmology and Nongalactic Astrophysics. The paper analyzes the depolarization of radio galaxy ILTJ012215.21+254334.8 using LOFAR’s Sky Survey data, revealing a preferred three-component model and highlighting turbulence in the magneto-ionic medium.

The overlay is here:

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

The second paper is “Rapid cosmological inference with the two-loop matter power spectrum” by Thomas Bakx (Utrecht U., NL), Henrique Rubira (Ludwig-Maximilians-Universität, DE), Nora Elisa Chisari (Utrecht) and Zvonimir Vlah (Ruđer Bošković Institute, Croatia). This was also published on Tuesday February 10th in the folder Cosmology and Nongalactic Astrophysics. This paper uses the COBRA method to compute the two-loop effective field theory power spectrum of dark matter density fluctuations, providing more precise cosmological constraints than the one-loop EFT.

The overlay for this one is here:

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

Next, published on Wednesday 11th February in the folder Astrophysics of Galaxies, is “Interpreting nebular emission lines in the high-redshift Universe” by Aswin P. Vijayan (U. Sussex, UK) and 9 others based in the UK, Taiwan, China and The Netherlands. This article examines the reliability of diagnostics used to estimate star formation rate and gas-phase oxygen abundance in high-redshift galaxies. It finds that variations in stellar populations and star-dust geometry. The overlay is here:

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

The fourth paper this week, also published on Wednesday 11th February, but in the folder Instrumentation and Methods for Astrophysics is “Derivative-Aligned Anticipation of Forbush Decreases from Entropy and Fractal Markers” by Juan D. Perez-Navarro & David Sierra Porta (Universidad Tecnológica de Bolívar, Colombia). The paper presents a feature-based framework for predicting Forbush decreases, i.e. rapid, temporary drops in galactic cosmic ray (GCR) intensity (up to tens of percent) caused by solar wind disturbances, typically Coronal Mass Ejections (CMEs) or high-speed streams from coronal holes, in neutron-monitor records using various computational methods. The approach is reproducible, operates on native station units, and is stable.

Here is the overlay:

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

The fifth paper, the penultimate for this week, is “Supermassive black hole growth from stellar binary encounters” by Aubrey L Jones and Benjamin C Bromley (University of Utah, USA). This paper explores the growth of supermassive black holes (SMBHs) through stellar accretion via the Hill’s mechanism, predicting capture rates and identifying potential growth drivers in 91 galaxies. It was published on Thursday 11th February 2026 in the folder Astrophysics of Galaxies.

The overlay is here:

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

Finally for this week we have “Dynamics in the Cores of Self-Interacting Dark Matter Halos: Reduced Stalling and Accelerated Core Collapse” by Frank C. van den Bosch and Shashank Dattathri (Yale University, USA). This study uses simulations to explore core dynamics in self-interacting dark matter (SIDM) halos. Findings suggest strong self-interactions prevent core stalling and buoyancy, leading to accelerated core collapse. This was published yesterday, on Friday 13th February 2026, in the folder Astrophysics of Galaxies.

The overlay is here:

You can find the published version of the article here, and the Mastodon announcement is here:

And that concludes this week’s update. I will do another next Saturday.

1 Comment »

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