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.

