Although it’s holiday season for some, 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 four papers, bringing the number in Volume 9 (2026) to 167 and the total so far published by OJAp up to 615.
I continue to include the posts made on our Mastodon account (on Fediscience); these announcements also show the DOI for each paper.
New Publication at the Open Journal of Astrophysics: "Small-scale turbulence alongside large-scale turbulence in a z=1.87 star-forming galaxy with an outflowing wind, revealed by multi-point structure functions" by Itzhak Goldman (Afeka College, Israel)
The second paper for this week, published on Thursday 6th August in the folder Astrophysics of Galaxies, is “From Clumps to Sheets: Geometry Controls the Temperature PDF of Multi-Phase Gas” by Zirui Chen and S. Peng Oh (UC Santa Barbara, USA). This study uses 3D hydrodynamic simulations to show that the temperature probability distribution functions (PDFs) of multi-phase turbulent gas differ significantly under interstellar medium (ISM) and circumgalactic medium (CGM) conditions.
The overlay looks like this:
The official version of the paper can be found on arXiv here and the Fediverse announcement here:
New Publication at the Open Journal of Astrophysics: "From Clumps to Sheets: Geometry Controls the Temperature PDF of Multi-Phase Gas" by Zirui Chen and S. Peng Oh (UC Santa Barbara, USA)
New Publication at the Open Journal of Astrophysics: "First Detection of Extensive Air Showers Using a Small-Aperture Fluorescence Telescope" by M. Zotov (M.V. Lomonosov Moscow State University, Russia) and 7 others based in Russia and Armenia
The fourth and final paper of the week was published on Friday 7th August in the folder Cosmology and Nongalactic Astrophysics: “TDCOSMO XXVI: Uniform Lens Modeling of Eight Doubly Imaged Quasars“, by Ryan Brady (Stony Brook University, USA) and 9 others based all around the world, presents a new method for analyzing doubly imaged quasars using the Hubble Space Telescope, revealing that arc surface brightness is key to precision in mass model measurements.
The overlay is here:
The officially-accepted version of the paper can be found on arXiv here and the Fediverse announcement here:
New Publication at the Copen Journal of Astrophysics: "TDCOSMO XXVI: Uniform Lens Modeling of Eight Doubly Imaged Quasars" by Ryan Brady (Stony Brook University, USA) and 9 others based around the world.
That’s all for this week. We have about a dozen more papers accepted and waiting for the authors to put the final version on arXiv, which they will presumably do when they’re back from holiday. I’ll do an update next weekend and we’ll see!
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:
New Publication at the Open Journal of Astrophysics: "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)
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:
New Publication at the Open Journal of Astrophysics: "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)
New Publication at the Open Journal of 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
New Publication at the Open Journal of Astrophysics: "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 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:
New Publication at the Open Journal of Astrophysics: "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).
The sixth and final 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:
New Publication at the Open Journal of Astrophysics: "Density reconstruction from biased tracers: Testing the equivalence principle through consistency relations" by Lawrence Dam and Omar Darwish (Université de Genève, Switzerland)
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.
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:
New Publication at the Open Journal of Astrophysics: "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)
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:
New Publication at the Open Journal of Astrophysics: "Cygnus X-3 as a PeVatron and the LHAASO 2025 data" by Michael Kachelriess & E. Lammert (NTNU, Trondheim, Norway)
New Publication at the Open Journal of Astrophysics: "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.
New Publication at the Open Journal of Astrophysics: "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)
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:
New Publication at the Open Journal of Astrophysics: "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)
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:
New Publication at the Open Journal of Astrophysics: "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)
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:
New Publication at the Open Journal of Astrophysics: "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)
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!
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 129 and the total so far published by OJAp up to 577.
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 23rd June, is “Interpretable machine learning of halo gas density profiles: a sensitivity analysis of cosmological hydrodynamical simulations” by Daniele Sorini & Sownak Bose (Durham University, UK), Mathilda Denison (U. Penn., USA) and Romeel Davé (University of Edinburgh, UK). This study uses cosmological hydrodynamical simulations and a random forest algorithm to understand how feedback processes affect the gas distribution in galaxies by predicting gas density profiles in various models. 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:
New Publication atthe Open Journal of Astrophysics: "Interpretable machine learning of halo gas density profiles: a sensitivity analysis of cosmological hydrodynamical simulations" by Daniele Sorini & Sownak Bose (Durham U., UK), Mathilda Denison (U. Penn., USA) and Romeel Davé (U. Edinburgh, UK)
The second paper for this week, published on Wednesday June 24th in the folder Astrophysics of Galaxies is “Dual-disk galaxies and thermal states of circumgalactic medium” by Masafumi Noguchi (Tohoku University, Japan). This paper explores the suggestion that the transition from thick to dual-disk galaxies is influenced by thermal changes in the circumgalactic medium (CGM), which also affects star formation.
The overlay looks like this:
The official version of the paper can be found on arXiv here and the Fediverse announcement here:
New Publication at the Open Journal of Astrophysics: "Dual-disk galaxies and thermal states of circumgalactic medium" by Masafumi Noguchi (Tohoku University, Japan).
New Publication at the Open Journal of Astrophysics: "Mass Transfer in Tidally Heated Stars Orbiting Massive Black Holes and Implications for Repeating Nuclear Transients" by Philippe Z. Yao and Eliot Quataert (Princeton University, USA)
And that concludes this week’s update. It has been another slow week on the publishing front. We have a steadily growing backlog of papers accepted for publication but with final versions yet to appear on arXiv. I suppose it’s the holidays…
P.S. The other day I checked the stats for the Open Journal of Astrophysics and saw that we’ve passed 8,000 citations. The average number of citations per paper is 14.0, which is not bad when you consider that over half the papers were published under a year ago…
It’s Saturday morning again, so it’s time again for an update of papers published at the Open Journal of Astrophysics. Since the last update we have published seven new papers, which brings the number in Volume 8 (2025) up to 105, and the total so far published by OJAp up to 340. I expect we’ll pass the century for this year sometime next week. I had expected a bit of a slowdown in July, but that doesn’t seem to have happened. Anyway, with the century for the year having been achieved, the next target is 120 (the total number we published last year). At the current rate I expect us to reach that sometime in August.
The papers published this week, with their overlays, are as follows. You can click on the images of the overlays to make them larger should you wish to do so.
The officially-accepted version can be found on arXiv here.
The second paper of the week, also published on Tuesday 22nd July but in the folder Cosmology and Nongalactic Astrophysics, is “Do We Know How to Model Reionization?” by Nick Gnedin (University of Chicago, USA). This paper discusses the similarities and differences between the radiation fields produced by different numerical simulations of cosmic reionization. The overlay is here:
You can find the officially accepted version of the paper on arXiv here.
The third paper of the week is “The effects of projection on measuring the splashback feature” by Xiaoqing Sun (MIT), Stephanie O’Neil (U. Penn.), Xuejian Shen (MIT) and Mark Vogelsberger (MIT), all based in the USA. This paper describes an investigation whether projection effects could lead to any systematic bias in determining the position of the boundary between infalling and accreting matter around haloes. It was published on Wednesday 23rd July in the folder Astrophysics of Galaxies. The overlay is here:
The officially-accepted version can be found on arXiv here.
The fourth paper of the week, also published on Wednesday 22nd July in the folder Astrophysics of Galaxies, is “Host galaxy identification of LOFAR sources in the Euclid Deep Field North” by Laura Bisigello, Marika Giulietti, Isabella Prandoni, Marco Bondi, & Matteo Bonato (INAF, Bologna, Italy), Manuela Magliocchetti (INAF-IAPS Roma, Italy), Huub Rottgering (Leiden Observatory, Netherlands), Leah, K. Morabito (Durham University, UK) and Glenn, J. White (Open Universirty, UK). This presents a catalogue of optical and near-infrared counterparts to radio sources detected in the Euclid Deep Field North using observations from the LOw-Frequency ARray (LOFAR). The overlay is here:
The final, accepted version of the paper is on arXiv here.
Fifth one up is “Constraining the dispersion measure redshift relation with simulation-based inference” by Koustav Konar (Ruhr University Bochum), Robert Reischke (Universität Bonn), Steffen Hagstotz (Ludwig-Maximilians Universität München), Andrina Nicola (Bonn) and Hendrik Hildebrandt (Bochum); all authors based in Germany. This was published on Thursday 24th July in the folder Cosmology and NonGalactic Astrophysics. It discusses using simulations to develop the use of Dispersion Measures of Fast Radio Bursts as cosmological probes. The overlay is here:
You can find the officially accepted version on arXiv here.
The penultimate (sixth) article published this week is “Generating Dark Matter Subhalo Populations Using Normalizing Flows” by Jack Lonergan (University of Southern California), Andrew Benson (Carnegie Observatories) and Daniel Gilman (University of Chicago), all based in the USA. This paper describes a generative AI approach to subhalo populations, trained using the semi-analytical model Galacticus. This paper was published yesterday (i.e. on Friday 25th July) in the folder Astrophysics of Galaxies.
It’s Saturday morning again so time for an update of papers published at the Open Journal of Astrophysics. Since the last update we have published eight new papers, which brings the number in Volume 8 (2025) up to 82, and the total so far published by OJAp up to 317. With about half the year gone, we’re on target to published around 160 papers this year.
The papers published this week, with their overlays, are as follows. You can click on the images of the overlays to make them larger should you wish to do so.
The first paper to report is “Spectroscopic and X-ray Modeling of the Strong Lensing Galaxy Cluster MACS J0138.0-2155” by Abigail Flowers (University of California at Santa Cruz; UCSZ), Jackson H. O’Donnell (UCSZ), Tesla E. Jeltema (UCSZ), Vernon Wetzell (U. Pennsylvania) & M. Grant Roberts (UCSZ). This artticle, which is in the folder marked Cosmology and NonGalactic Astrophysics, presents a study of the mass distribution and substructure of a galaxy cluster that acts as a gravitational lens for a source galaxy at z=1.95 that contains two supernovae. It was published on 23rd June 2025. The overlay is here:
The officially-accepted version can be found on arXiv here.
“Illuminating the Physics of Dark Energy with the Discovery Simulations” by Gillian D. Beltz-Mohrmann (Argonne National Laboratory, USA) and 12 others based in the USA and Spain. This describes new high-resolution cosmological simulations providing a testbed for alternative cosmological probes that may offer additional constraining power beyond Baryon Accoustic Oscillations. It is filed in the folder marked Cosmology and NonGalactic Astrophysics.
The overlay is here:
You can read the final accepted version on arXiv here.
You can find the officially-accepted version of the paper on arXiv here.
The thirtd paper is “On the Use of WGANs for Super Resolution in Dark-Matter Simulations” by John Brennan (Maynooth), Sreedhar Balu (U. Melbourne), Yuxiang Qin (ANU), John Regan (Maynooth) and Chris Power (U. Western Australia). This one is also in the folder marked Astrophysics of Galaxies and was also published on Monday 23rd June. It is about using the Wasserstein Generative Adversarial Network (WGAN) model to increase the particle resolution of dark-matter-only simulations of galaxy formation. The overlay is here:
You can find the officially-accepted version of the paper on arXiv here.
You can find the officially-accepted version on arXiv here.
The fifth paper this week is “Compact Binary Formation in Open Star Clusters III: Probability of Binary Black Holes Hidden Inside of Gaia Black Hole Binary” by Ataru Tanikawa (Fukui Prefectural University, Japan), Long Wang (Sun Yat-sen University, China), Michiko S. Fujii (University of Tokyo, Japan), Alessandro A. Trani (Niels Bohr Institute, Denmark), Toshinori Hayashi (Kyoto University, Japan) and Yasushi Suto (Kochi University of Technology, Japan). This one is in the folder marked Astrophysics of Galaxies and was published on Tuesday 24th June. It presents an investigation into whether some Gaia black hole binary systems may in fact involve three black holes, including a pair too compact to be resolved astrometrically. Here is the overlay:
You can find the officially-accepted paper on arXiv here.
Next we have “Rapid identification of lensed type Ia supernovae with color-magnitude selection” by Prajakta Mane (IISER) and Anupreeta More & Surhud More (IUCAA), all based in India. This paper presents an extension of the use of color-magnitude diagrams, used previously as a means to identify lensed supernovae, with applications to LSST-like photometric data. It is in the folder marked Astrophysics of Galaxies and was published on Thursday 26th June.
The officially-accepted version of the article can be found on arXiv here.
You can find the officially-accepted version on arXiv here.
Eighth and last paper this week is “Exploring the Core-galaxy Connection” by Isabele Lais de Souza Vitório (U. Michigan) and Michael Buehlmann, Eve Kovacs, Patricia Larsen, Nicholas Frontiere & Katrin Heitmann (Argonne National Laboratory, USA). This one is in the folder Cosmology and Nongalactic Astrophysics and was published on Friday 27th June 2025 (i.e. yesterday).
The overlay is here:
You can find the officially-accepted version on arXiv here.
And that’s all the papers for this week. I do, however, have some more news to pass on. We are delighted to welcome two new recruits to our Editorial Board, Dr Foteini Oikonomou of the Norwegian University of Science and Technology, who specializes in the application of particle physics theories to high-energy astrophysical phenomena, and Dr Heloise Stevance of Oxford University (UK), who specializes in the interface between Machine Learning and Astrophysics.
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In the Dark 