It’s Saturday once again, so time for another update of activity at the Open Journal of Astrophysics. Since the last update we have published a further five papers, bringing the number in Volume 9 (2026) to 99 and the total so far published by OJAp up to 547. We didn’t quite make it to a hundred for the year last week, but will do so with the next paper.
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 this week is “Formation of Close Binaries through Massive Black Hole Perturbations and Chaotic Tides” by Howard Hao-Tse Huang and Wenbin Lu (University of California at Berkeley, USA). This one was published on Wednesday 6th May 2026 in the folder Astrophysics of Galaxies. The paper presents a model of massive black hole-binary systems, showing that repeated tidal interactions can lead to the creation of hyper-velocity stars and other nuclear transients.
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: "Formation of Close Binaries through Massive Black Hole Perturbations and Chaotic Tides" by Howard Hao-Tse Huang & Wenbin Lu (U. California Berkeley, USA)
The second paper for this week, also Wednesday 6th May, but in the folder Cosmology and Nongalactic Astrophysics is “Detection of supernova magnitude fluctuations induced by large-scale structure” by Andrew Nguyen (Swinburne Institute of Technology, Australia) and 58 others based all around the world. This study uses supernovae and galaxy velocities to measure the universe’s structure growth rate, confirming the Planck LambdaCDM model prediction. The methodology is validated and shows potential for future research.
The overlay for this one is here:
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: "Detection of supernova magnitude fluctuations induced by large-scale structure" by Andrew Nguyen (Swinburne Institute of Technology, Australia) and 58 others based all around the world.
Next one up, the third paper of the week, also published on Wednesday 6th May in the folder Cosmology and Nongalactic Astrophysics is “Comparing cosmic shear nulling methods for Stage-IV surveys” by Naomi Clare Robertson and Alex Hall (University of Edinburgh, UK). This study compares three strategies for reducing baryon feedback impact on cosmic shear measurements. All methods effectively mitigate bias, with varying degrees of efficiency and information preservation.
The overlay for this one is here:
The final, accepted version can be found on arXiv here and the Mastodon announcement is here:
New Publication at the Open Journal of Astrophysics: "Comparing cosmic shear nulling methods for Stage-IV surveys" by Naomi Clare Robertson & Alex Hall (U. Edinburgh, UK)
The fourth paper this week, published on Thursday May 7th, is “Egent: An Autonomous Agent for Equivalent Width Measurement” by Yuan-Sen Ting & Serat Mahmud Saad (Ohio State University, USA), Fan Liu (National Astronomical Observatories, Beijing, China), and Yuting Shen (Georgia Institute of Technology, USA). Egent is an autonomous agent that combines multi-Voigt profile fitting with large language model visual inspection for efficient, automated analysis of raw flux spectra, validated against expert measurements. This one is in the folder Instrumentation and Methods for Astrophysics. The associated software can be found here.
The overlay is here:
The officially accepted version can be found on arXiv here and here is the Mastodon announcement:
New Publication at the Open Journal of Astrophysics: "Egent: An Autonomous Agent for Equivalent Width Measurement" by Yuan-Sen Ting & Serat Mahmud Saad (Ohio State U., USA), Fan Liu (National Astronomical Observatories, China) and Yuting Shen (Georgia Institute of Technology, USA)
The fifth and final article of this week was published on Friday 8th May in the folder Astrophysics of Galaxies. The title is “DiffstarPop: A generative physical model of galaxy star formation history” and it is by Alex Alarcon (Institute of Space Sciences, Barcelona, Spain), Andrew P. Hearin , Matthew R. Becker & Gillian Beltz-Mohrmann (Argonne National Laborarory, USA), and Andrew Benson & Sachi Weerasooriya (Carnegie Observatories, USA). DiffstarPop is a model that accurately and rapidly reproduces statistical distributions of galaxy star formation histories (SFH), using parameters related to galaxy formation physics.
The overlay is here:
You can find the authorized version of this paper on arXiv here and the Fediverse announcement is here:
New Publication at the Open Journal of Astrophysics: "DiffstarPop: A generative physical model of galaxy star formation history" by Alex Alarcon (Institute of Space Sciences, Barcelona, Spain), Andrew P. Hearin , Matthew R. Becker & Gillian Beltz-Mohrmann (Argonne National Laborarory, USA), and Andrew Benson & Sachi Weerasooriya (Carnegie Observatories, USA)
Here we are, on schedule, with 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 94 and the total so far published by OJAp up to 542. I checked the corresponding update for last year (on 3rd May 2025), and we’ve had an increase from 54 to 94 in papers published (about 74%) between the first four months of 2025 and the first four months of 2026.
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 this week is “DESI-DR1 3 × 2-pt analysis: consistent cosmology across weak lensing surveys” by Anna Porredon (CIEMAT, Madrid, Spain) and 72 others (DESI Colllaboration). This paper was published on Tuesday 28th April in the folder Cosmology and Nongalactic Astrophysics. This paper presents a joint cosmological analysis of galaxy clustering and gravitational lensing observations, providing consistent constraints on cosmological parameters. The analysis also introduces a new blinding procedure to prevent confirmation bias. See this post for news of an important DESI milestone.
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: "DESI-DR1 3 × 2-pt analysis: consistent cosmology across weak lensing surveys" by Anna Porredon (CIEMAT, Madrid, Spain) and 72 others (DESI Colllaboration)
The second paper for this week, also published on Tuesday 28th April but in the folder High-Energy Astrophysical Phenomena is “Masers and Broad-Line Mapping Favor Magnetically-Dominated AGN Accretion Disks” by Philip F. Hopkins (Caltech, USA), Dalya Baron (Stanford U., USA) and Joanna M. Piotrowska (Caltech). This one presents a new constraint on supermassive black hole accretion disks physics, suggesting that outer regions are likely in a ‘hyper-magnetized’ state, as thermal or radiation pressure models appear inconsistent.
The overlay for this one is here:
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: "Masers and Broad-Line Mapping Favor Magnetically-Dominated AGN Accretion Disks" by Philip F. Hopkins (Caltech, USA), Dalya Baron (Stanford U., USA) and Joanna M. Piotrowska (Caltech)
Next one up, the third paper of the week, is “Galaxy mergers and disk angular momentum evolution: stellar halos as a critical test” by Eric F. Bell (U. Michigan, Ann Arbor, USA), Richard D’Souza (Vatican Observatory), Monica Valluri & Katya Gozman (U. Michigan). This was published on Wednesday 29th April in the folder Astrophysics of Galaxies. The paper argues that satellite accretion impacts the angular momentum evolution of galaxies, often causing significant reorientation. This process is detectable in Milky Way-mass galaxies so the idea is testable observationally.
The overlay for this one is here:
The final, accepted version can be found on arXiv here and the Mastodon announcement is here:
New Publication at the Open Journal of Astrophysics: "Galaxy mergers and disk angular momentum evolution: stellar halos as a critical test" by Eric F. Bell (U. Michigan, Ann Arbor, USA), Richard D'Souza (Vatican Observatory), Monica Valluri & Katya Gozman (U. Michigan)
The fourth paper this week, published on Thursday April 30th, is “Time-Dilation Methods for Extreme Multiscale Timestepping Problems” by Philip F. Hopkins and Elias R. Most (Caltech, USA). This paper is in the folder Instrumentation and Methods for Astrophysics: it presents a new method for astrophysical simulations that modulates time evolution with a variable dilation/stretch factor, improving efficiency and accuracy in modeling processes across different scales.
The overlay is here:
The finally accepted version of this paper can be found here and the Mastodon announcement follows:
New Publication at the Open Journal of Astrophysics: "Time-Dilation Methods for Extreme Multiscale Timestepping Problems" by Philip F. Hopkins and Elias R. Most (Caltech, USA)
The fifth article of this week was also published on Thursday 30th April, but in the folder Astrophysics of Galaxies. The title is “Cosmic Rays on Galaxy Scales: Progress and Pitfalls for CR-MHD Dynamical Models” and the author is Philip F. Hopkins (Caltech, USA) who has three papers featured this week. The paper presents an overview of cosmic ray (CR) modeling, highlighting its influence on galactic physics and star formation. It addresses previous modeling errors and presents new methods for full-spectrum dynamics.
The overlay is here:
You can find the authorized version of this paper on arXiv here and the Fediverse announcement is here:
New Publication at the Open Journal of Astrophysics: "Cosmic Rays on Galaxy Scales: Progress and Pitfalls for CR-MHD Dynamical Models" by Philip F. Hopkins (Caltech, USA)
New Publication at the Open Journal of Astrophysics: "Baryonification III: An accurate analytical model for the dispersion measure probability density function of fast radio bursts" by MohammadReza Torkamani (Universität Bonn, Germany) and 8 others based in Germany, Switzerland, UK and Sweden
New Publication at the Open Journal of Astrophysics: "The stellar and dark matter distributions in early-type galaxies measured by stacked weak gravitational lensing" by Momoka Fujikawa & Masamune Oguri (Chiba University, Japan)
So here we are again, on a Saturday morning, with another update of activity at the Open Journal of Astrophysics. Since the last update we have published a further five papers, bringing the number in Volume 9 (2026) to 87 and the total so far published by OJAp up to 535.
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 this week is “Bayesian Cosmic Void Finding with Graph Flows” by Leander Thiele (U. Tokyo, Japan). This was published on Monday 20th April in the folder Cosmology and Nongalactic Astrophysics. The paper presents a method using a deep graph neural network to identify cosmic voids in sparse galaxy surveys, improving upon traditional deterministic algorithms by considering the problem’s probabilistic nature. The overlay is here:
You can find the officially accepted version on arXiv here and the announcement on Fediverse here:
The second paper for this week, published on Wednesday 22nd April in the folder Astrophysics of Galaxies, is “Sifting for a Stream: The Morphology of the 300S Stellar Stream” by Benjamin Cohen (U. Chicago, USA) and 20 others distributed around the world. This study analyzes the morphology of the $300S$ stellar stream, revealing three density peaks, a possible gap, and a kink, suggesting significant influence from the Large Magellanic Cloud on its structure.
The overlay for this one is here:
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: "Sifting for a Stream: The Morphology of the 300S Stellar Stream" by Benjamin Cohen (U. Chicago, USA) and 20 others distributed around the world.
New Publication at the Open Journal of Astrophysics: "IRMaGiC: Extending Luminous Red Galaxy Selection into the Infrared with Joint Rubin Observatory’s Large Survey of Space Time and Roman’s High Latitude Imaging Survey" by Zhiyuan Guo & Chris. W. Walter (Duke U., USA) and Eli S. Rykoff (Stanford U., USA) on behalf of the LSST Dark Energy Science Collaboration
New Publication at the Open Journal of Astrophysics: "The Diagnostic Temperature Discrepancy as Evidence for Non-Maxwellian Coronal Electrons" by Victor Edmonds (Final Stop Consulting, USA)
The fifth and final paper for this week was published on Friday 24th April in the folder Astrophysics of Galaxies. The title is “Galaxy evolution in the post-merger regime. IV – The long-term effect of mergers on galactic stellar mass growth and distribution” by Sara L. Ellison (U. Victoria, Canada) and Leonardo Ferreira (Universidade Federal do Rio Grande, Brazil). This study uses a large sample of post-merger galaxies to demonstrate that galaxy mergers trigger significant and extended stellar mass growth in their central regions, independent of stellar population modelling.
The overlay is here:
You can find the authorized version of this paper on arXiv here and the Fediverse announcement is here:
New Publication at the Open Journal of Astrophysics: "Galaxy evolution in the post-merger regime. IV – The long-term effect of mergers on galactic stellar mass growth and distribution" by Sara L. Ellison (U. Victoria, Canada) and Leonardo Ferreira (Universidade Federal do Rio Grande, Brazil)
New Publication at the Open Journal of Astrophysics: "Galaxy evolution in the post-merger regime. IV – The long-term effect of mergers on galactic stellar mass growth and distribution" by Sara L. Ellison (U. Victoria, Canada) and Leonardo Ferreira (Universidade Federal do Rio Grande, Brazil)
It is Saturday morning, and therefore time for yet 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 82 and the total so far published by OJAp up to 530.
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.
New Publication at the Open Journal of Astrophysics: "Beyond Spherical geometry: Unraveling complex features of objects orbiting around stars from its transit light curve using deep learning" by Ushasi Bhowmick & Shivam Kumaran (ISRO, Ahmedabad, India)
The second paper for this week, also published on Monday 13th April but in the folder Astrophysics of Galaxies, is “statmorph-lsst: Quantifying and correcting morphological biases in galaxy surveys” by Elizaveta Sazonova (U. Waterloo, Canada) and an international cast of 18 others. This paper presents an investigation of potential biases in quantitative morphology metrics used in galaxy evolution studies, proposing two new measurements to resolve biases, and provides a related Python package (statmorph-lsst), which can be found here on github.
The overlay for this one is here:
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: "statmorph-lsst: Quantifying and correcting morphological biases in galaxy surveys" by Elizaveta Sazonova (U. Waterloo, Canada) and an international cast of 18 others.
Next one up, the third paper of the week, one of four published on Friday 17th April, is “Disentangling the galactic and intergalactic components in 313 observed Lyman-alpha line profiles between redshift 0 and 5” by Siddhartha Gurung-López (Universitat de València, Spain) and 7 others based in Spain and Germany. Published in the folder Astrophysics of Galaxies, this paper uses the zELDA package to analyze Lyman-alpha photons from star-forming galaxies, revealing IGM effects dominate Lyman-alpha observability at high redshifts, while galactic outflows become more important at lower z.
The overlay for this one is here:
The final, accepted version can be found on arXiv here and the Mastodon announcement is here:
New Publication at the Open Journal of Astrophysics: "Disentangling the galactic and intergalactic components in 313 observed Lyman-alpha line profiles between redshift 0 and 5" by Siddhartha Gurung-López (Universitat de València, Spain) and 7 others based in Spain and Germany.
New Publication at the Open Journal of Astrophysics: "Using Symbolic Regression to Emulate the Radial Fourier Transform of the Sérsic Profile for Fast, Accurate and Differentiable Galaxy Profile Fitting" by Tim B. Miller (Northwestern University, USA) and Imad Pasha (Yale University, USA)
The fifth paper for this week is “The THESAN project: Lyman-alpha emitters as probes of ionized bubble sizes” by Meredith Neyer (MIT, USA) and 6 others based in the USA, Colombia, Canada, Japan and UK. The study uses THESAN simulations to explore how Lyman-alpha emitters (LAEs) trace ionized bubble sizes during the Epoch of Reionization, providing a framework for interpreting LAE surveys. This was published on Friday 17th April in the folder Astrophysics of Galaxies.
The overlay for this one is here:
You can find the authorized version of this paper on arXiv here and the Fediverse announcement is here:
New Publication at the Open Journal of Astrophysics: "The THESAN project: Lyman-alpha emitters as probes of ionized bubble sizes" by Meredith Neyer (MIT, USA) and 6 others based in the USA, Colombia, Canada, Japan and UK.
New Publication at the Open Journal of Astrophysics: "Closed-Form Statistical Relations Between Projected Separation, Semimajor Axis, Companion Mass, and Host Acceleration" by Timothy D Brandt (Space Telescope Science Institute, USA)
With permission, I have time for yet another Saturday morning update of activity at the Open Journal of Astrophysics. Since the last update we have published a further five papers, bringing the number in Volume 9 (2026) to 76 and the total so far published by OJAp up to 524.
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 this week is “Lagrangian versus Eulerian Methods for Toroidally-Magnetized Isothermal Disks” by Yashvardhan Tomar and Philip F. Hopkins (California Institute of Technology, USA). This study re-evaluates previous research on toroidally-magnetized disks, using two Lagrangian methods. The results suggest that sustained midplane toroidal fields in recent simulations are not a numerical artefact. It was published on Tuesday April 7th 2026 in the folder High-Energy Astrophysical Phenomena.
The overlay 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: "Lagrangian versus Eulerian Methods for Toroidally-Magnetized Isothermal Disks" by Yashvardhan Tomar and Philip F. Hopkins (Caltech, USA)
The second paper for this week, published on Wednesday 8th Apil in the folder Instrumentation and Methods for Astrophysics, is “Teaching Astronomy with Large Language Models” by Yuan-Sen Ting and Teaghan O’Briain (Ohio State University, USA). The paper introduces AstroTutor, an AI-enhanced astronomy tutoring system, to improve undergraduate astronomy education and AI literacy. It found that structured AI integration can enhance learning and critical evaluation skills. The primary classification on arXiv for this paper is physics.ed-ph but it is cross-listed on astro-ph which qualifies it for consideration.
The overlay for this one is here:
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: "Teaching Astronomy with Large Language Models" by Yuan-Sen Ting and Teaghan O'Briain (Ohio State University, USA)
Next one up, the third paper of the week, also published on Wednesday 8th April, is “Statistical Predictions of the Accreted Stellar Halos around Milky Way-Like Galaxies” by J. Sebastian Monzon & Frank C. van den Bosch (Yale University, USA) and Martin P. Rey (University of Bath, UK). This one was published in the section Astrophysics of Galaxies; it describes new model to track formation of stellar halos in Milky Way-like galaxies, revealing their sensitivity to the fate of the largest satellite and whether accretion is early or late.
The overlay for this one is here:
The final, accepted version can be found on arXiv here and the Mastodon announcement is here:
New Publication at the Open Journal of Astrophysics: "A Tale of Tails: Star Formation and Stripping in Jellyfish Galaxies in the Strong Lensing Cluster MACS J0138.0-2155" by Catherine C. Gibson, Jackson H. O'Donnell and Tesla E. Jeltema (UC Santa Cruz, USA)
The fifth and final paper for this week is “Investigating ionising sources and the complex interstellar medium of GHZ2 at z=12.3” by M. Castellano (INAF Osservatorio Astronomico di Roma, Italy) and 29 others based all around the world. This was also published on Thursday 9th April in the folder Astrophysics of Galaxies. The paper uses deep observations of galaxy GHZ2 to explore the sources of ionising radiation and interstellar medium properties at cosmic dawn. Findings suggest a stratified environment and a hard ionising radiation component.
The overlay for this one is here:
The officially-accepted version of this one can be found on arXiv here and the Mastodon announcement is here
New Publication at the Open Journal of Astrophysics: "Investigating ionising sources and the complex interstellar medium of GHZ2 at z=12.3" by M. Castellano (INAF Osservatorio Astronomico di Roma, Italy) and 29 others based around the world.
It may be the Easter weekend, but it’s still time for a Saturday morning 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 71 and the total so far published by OJAp up to 519. This update coimpletes the first quarter of 2026, which suggests that if we continue to publish at the same rate we’ll reach about 280 for the year.
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.
New Publication at the Open Journal of Astrophysics: "Testing halo models for constraining astrophysical feedback with multi-probe modeling: I. 3D Power spectra and mass fractions" by Pranjal R. S. (U. Arizona, USA), Shivam Pandey Johns Hopkins U., USA), Dhayaa Anbajagane (U. Chicago, USA), Elisabeth Krause (U. Arizona) and Klaus Dolag (Max Planck Institute for Astrophysics, Germany)
The second paper for this week, also published on Tuesday March 31st in the folder Cosmology and Nongalactic Astrophysics, is “Validation of the DESI-DR1 3×2-pt analysis: scale cut and shear ratio tests” by Ni Putu Audita Placida Emas (Swinburne University of Technology, Australia) and an international cast of 56 others. This study validates the combined analysis of galaxy clustering and weak gravitational lensing data from various surveys, ensuring accurate tests of the standard cosmological model using future Stage-IV surveys
The overlay for this one is here:
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: "Validation of the DESI-DR1 3×2-pt analysis: scale cut and shear ratio tests" by Ni Putu Audita Placida Emas (Swinburne University of Technology, Australia) and an international cast of 56 others.
Next one up, the third paper of the week, also published on Tuesday March 31st in the folder Cosmology and Nongalactic Astrophysics, is “Differentiable Stochastic Halo Occupation Distribution with Galaxy Intrinsic Alignments” by Sneh Pandya and Jonathan Blazek (both of Northeastern University, USA). This is a paper introducing diffHOD-IA, a differentiable model for galaxy population analysis that incorporates intrinsic alignments and halo occupation distribution. It’s validated against existing models and can be used in next-generation weak-lensing analyses.
The overlay for this one is here:
The final, accepted version can be found on arXiv here and the Mastodon announcement is here:
New Publication at the Open Journal of Astrophysics: "Differentiable Stochastic Halo Occupation Distribution with Galaxy Intrinsic Alignments" by Sneh Pandya and Jonathan Blazek (Northeastern U., USA)
The fourth and final paper this week, published on Wednesday April 1st (but not a joke), is “The Growth of Dust in Galaxies in the First Billion Years with Applications to Blue Monsters” by Desika Narayanan (U. Florida, USA) and 11 others based in the USA and Europe. This one is in the folder Astrophysics of Galaxies; it presents a simulation-based study of dust accumulation in early galaxies via supernovae production and rapid growth on tiny dust grains, with local density and grain size being important factors.
The overlay is here:
The finally accepted version of this paper can be found here and the Mastodon announcement is here:
New Publication at the Open Journal of Astrophysics: "The Growth of Dust in Galaxies in the First Billion Years with Applications to Blue Monsters" by Desika Narayanan (U. Florida, USA) and 11 others based in the USA and Europe.
A couple of days ago I received an email from a publisher offering to buy the Open Journal of Astrophysics. This happens from time to time, but it’s interesting to see the offer price increasing. This time it was for $150,000. I don’t know how that valuation was arrived at but I think OJAp is worth a lot more. But then there is a difference between price and value…
The publisher in question this time was XLESCIENCE, which is based in India and which charges typical Article Processing Charges of $1,200 per paper. I wonder how they would plan to make a profit from OJAp, which charges nothing? If a publisher did buy OJAp and started trying to charge an APC, people would just stop using it!
(The offer price is not the only reason I dismissed the approach, however. One other reason is that I don’t want to do business with a commercial publisher. Another reason I wouldn’t consider selling the Open Journal of Astrophysics is that I don’t actually own it. I did think about offering to sell them one of the many other journals I don’t own, just for a laught, but that might have been construed as attempted fraud…)
This episode reminded that some time ago I wrote a piece about funding open access journals. Having made the decision not to charge fees of any kind, we lack any source of income other than Maynooth University. I am very grateful for that support, but we are run on a shoestring budget. We are run entirely by volunteers and keep costs to an absolute minimum, but are not free.
I have written before about what I think the future of Diamond Open Access could look like. I would like to see a range of Diamond Open Access journals offering a choice for authors and serving different sub-disciplines. Most universities nowadays have publishing operations so there could be network of federated journals, some based on arXiv and some based on other repositories and others with different models, such as SciPost. Perhaps institutions are worried about the expense but, as we have shown the actual cost, is far less than they are wasting on Article Processing Charges.
Everything is going well at OJAp, but it is not reasonable that the expense of running a journal that serves the global astrophysics community should fall entirely on one small University in Ireland. It won’t be sustainable in the long run, either, if we continue to grow at the present rate. Compare us with the Diamond Open Access publisher SCIPOST, which has a long list of sponsors covering its costs; we have none. I know that money is very tight in astrophysics these days but if you have access to any potential sources of funding – then please consider supporting OJAp!
Once again it’s time for the usual Saturday morning update of activity at the Open Journal of Astrophysics. Since the last update we have published a further eight papers, bringing the number in Volume 9 (2026) to 67 and the total so far published by OJAp up to 515.
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.
New Publication at the Open Journal of Astrophysics: "Constraining Brown Dwarf Desert Formation Mechanisms through Bayesian Statistical Comparison of Observed and Simulated Populations" by Behrooz Karamiqucham (College of Charleston, USA)
The second paper for this week, also published on Tuesday March 24th, but in the folder Astrophysics of Galaxies, is “JWST observes the assembly of a massive galaxy at z ~ 4” by Aayush Saxena (University of Oxford, UK) and 20 others (based in the UK, Europe, USA, Brazil, Japan and China). The paper presents observations of radio galaxy TGSSJ1530+1049, revealing it as part of a dense structure of emitting objects likely to merge to form a massive galaxy within a few Gyr.
The overlay for this one is here:
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: "JWST observes the assembly of a massive galaxy at z ~ 4" by Aayush Saxena (University of Oxford, UK) and 20 others (based in the UK, Europe, USA, Brazil, Japan and China)
Next one up, the third paper of the week, also published on Tuesday March 24th in the folder Astrophysics of Galaxies, is “The dawn is quiet II: Gaia XP constraints on the Milky Way’s proto-Galaxy from very metal-poor MDF tails” by Boquan Chen (Ohio State U., USA), Matthew D. A. Orkney (Universitat de Barcelona, Spain), Yuan-Sen Ting (Ohio State U.) & Michael R. Hayden (U. Oklahoma, USA). The paper aegues that the Milky Way’s metallicity distribution suggests that its early evolution involved a moderate gas reservoir, sustained by weak continuous inflow, and star formation efficiency similar to the present value.
The overlay for this one is here:
The final, accepted version can be found on arXiv here and the Mastodon announcement is here:
New Publication at the Open Journal of Astrophysics: "The dawn is quiet II: Gaia XP constraints on the Milky Way’s proto-Galaxy from very metal-poor MDF tails" by Boquan Chen (Ohio State U., USA), Matthew D. A. Orkney (Universitat de Barcelona, Spain), Yuan-Sen Ting (Ohio State U.) & Michael R. Hayden (U. Oklahoma, USA)
The fourth paper this week, published on Wednesday 25th March 2026 in the folder High-Energy Astrophysical Phenomena is “Shaping the diffuse X-ray sky: Structure, Variability and Visibility” by Philipp Girichidis (Heidelberg U., Germany) and 7 others based in Germany, USA, Austria and Italy. The paper argues that the X-ray properties of the Local Bubble (LB), a low-density cavity in the solar neighborhood reveal that supernova events significantly influence X-ray emissions, which show pronounced temporal variability
The overlay is here:
The finally accepted version of this paper can be found here and the Mastodon announcement is here:
New Publication at the Open Journal of Astrophysics: "Shaping the diffuse X-ray sky: Structure, Variability and Visibility" by Philipp Girichidis (Heidelberg U., Germany) and 7 others based in Germany, USA, Austria and Italy
The fifth paper this week, also published on Wednesday 25th March 2026, is “Graph-Based Light-Curve Features for Robust Transient Classification” by Jesús D. Petro-Ramos David J. Ruiz-Morales, David Sierra Porta (Universidad Tecnológica de Bolívar, Colombia). This paper, which is in the folder Instrumentation and Methods for Astrophysics, uses graph-based representations of astronomical light curves for transient classification, achieving competitive multiclass performance, highlighting the potential of visibility graphs as a survey-agnostic tool for classifying time series.
This is the overlay:
The officially accepted version can be found on arXiv here and the Mastodon announcement follows:
New Publication at the Open Journal of Astrophysics: "Graph-Based Light-Curve Features for Robust Transient Classification" by Jesús D. Petro-Ramos David J. Ruiz-Morales, David Sierra Porta (Universidad Tecnológica de Bolívar, Colombia)
New Publication at the Open Journal of Astrophysics: "Redshift-Frame Systematics and Their Impact on the Hubble Constant from Pantheon+ Supernovae" by Said Laaroua (Santa Rosa Junior College, USA)
New Publication at the Open Journal of Astrophysics: "Why Machine Learning Models Systematically Underestimate Extreme Values II: How to Fix It with LatentNN" by Yuan-Sen Ting (Ohio State University, USA)
New Publication at the Open Journal of Astrophysics: "Catalog of Mock Stellar Streams in Milky Way-Like Galaxies" by Colin Holm-Hansen, Yingtian Chen and Oleg Y. Gnedin (University of Michigan, USA)
You will have observed that this week’s papers cover five of the six main categories on astro-ph. We haven’t yet managed to cover all six in a week – we only missed Solar and Stellar Astrophysics this time!
It’s Saturday once more, so it’s time for another update of activity at the Open Journal of Astrophysics. Since the last update we have published a further eight papers, bringing the number in Volume 9 (2026) to 59 and the total so far published by OJAp up to 507. We passed the 500 mark on Monday, and the week was also notable because we once again published at least one paper each working day.
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 this week is our 500th publication. The title is “The causal structure of galactic astrophysics” and the authors are Harry Desmond (U. Portsmouth, UK) and Joseph Ramsey (Carnegie Mellon U., USA). This paper was published on Monday March 16th 2026 in the folder Astrophysics of Galaxies. It proposes using causal discovery, a method for inferring data structure, to better utilize information in astrophysical data, demonstrated through an algorithm applied to a large galaxy dataset.
The overlay 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 causal structure of galactic astrophysics" by Harry Desmond (U. Portsmouth, UK) and Joseph Ramsey (Carnegie Mellon U., USA)
The second paper for this week, also published on March 16th in the folder Astrophysics of Galaxies, is “Finding the boundary: Using galaxy membership to inform galaxy cluster extent through machine learning” by Christine Hao, Stephanie O’Neil, Mark Vogelsberger, & Vinh Tran (MIT, USA), Lamiya Mowla (Wellesley College, USA) and Joshua S. Speagle (U. Toronto, Canada). This study uses neural networks and simulations to identify and map the transitional region between cluster and field galaxies, revealing it as a scattered area rather than a sharp boundary.
The overlay for this one is here:
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: "Finding the boundary: Using galaxy membership to inform galaxy cluster extent through machine learning" by Christine Hao, Stephanie O'Neil, Mark Vogelsberger, & Vinh Tran (MIT, USA), Lamiya Mowla (Wellesley College, USA) and Joshua S. Speagle (U. Toronto, Canada)
New Publication at the Open Journal of Astrophysics: "The Manticore-Local Cluster Catalogue: A Posterior Map of Massive Structures in the Nearby Universe" by Stuart McAlpine (Oskar Klein Centre, Stockholm U., Sweden)
The fourth paper this week, published on 18th March 2026 in the folder Solar and Stellar Astrophysics is “Vision-Based CNN Prediction of Sunspot Numbers from SDO/HMI Images” by Fabian C. Quintero-Pareja, Diederik A. Montano-Burbano, Santiago Quintero-Pareja & David Sierra Porta (Universidad Tecnológica de Bolívar, Colombia). This article describes a deep learning framework that uses convolutional neural networks to estimate daily sunspot numbers from solar images, offering a scalable and accurate method for solar monitoring.
The overlay is here:
The finally accepted version of this paper can be found here and the Mastodon announcement is here:
New Publication at the Open Journal of Astrophysics: "Vision-Based CNN Prediction of Sunspot Numbers from SDO/HMI Images" by Fabian C. Quintero-Pareja, Diederik A. Montano-Burbano, Santiago Quintero-Pareja & David Sierra Porta (Universidad Tecnológica de Bolívar, Colombia)
New Publication at the Open Journal of Astrophysics: "RABBITS –III. Modelling relativistic accretion discs around spinning black holes in galaxy formation simulations" by Dimitrios Irodotou (ICR, London) and 8 others based in China, Korea, Belgium, France, Finland and the UK.
The sixth paper this week is “A novel algorithm for GPU-accelerated particle-mesh interactions implemented in the QUOKKA code” by Chong-Chong He (Australia National University), Benjamin D. Wibking (Michigan State U., USA), Aditi Vijayan (ANU), Mark R. Krumholz (ANU) and Pak Shing Li (Shanghai Astronomical Observatory, China). This was published on Thursday 19th March in the folder Instrumentation and Methods for Astrophysics. The article introduces a GPU-optimized algorithm for particle-mesh interactions in hydrodynamics simulations, improving efficiency and scalability in simulations of star formation and feedback in galaxies.
The overlay is here:
The officially accepted version of this paper can be found on arXiv here, and the Mastodon announcement is here:
New Publication at the Open Journal of Astrophysics: "A novel algorithm for GPU-accelerated particle-mesh interactions implemented in the QUOKKA code" by Chong-Chong He (Australia National University), Benjamin D. Wibking Michigan State U., USA), Aditi Vijayan (ANU), Mark R. Krumholz (ANU) and Pak Shing Li (Shanghai Astronomical Observatory, China)
The penultimate, seventh, paper for this week is “The SEEDZ Simulations: Methodology and First Results on Massive Black Hole Seeding and Early Galaxy Growth” by Lewis Prole (NUI Maynooth, Ireland) and 15 others based in Ireland, Germany and the UK. This paper was also published on Thursday March 19th 2026 in the folder Astrophysics of Galaxies. Ir presents the SEEDZ simulations, studying the formation and growth of the universe’s first massive black holes, finding that these black holes initially grow faster than their host galaxies.
The overlay for this one is here:
The official version of this paper can be found here. This is the Mastodon announcement:
New Publication at the Open Journal of Astrophysics: "The SEEDZ Simulations: Methodology and First Results on Massive Black Hole Seeding and Early Galaxy Growth" by Lewis Prole (NUI Maynooth, Ireland) and 15 others based in Ireland, Germany and the UK.
And finally for this week, published yesterday (Friday 20th March 2026) in the folder Astrophysics of Galaxies, we have “Planes of satellites, at once transient and persistent” by Till Sawala (University of Helsinki, Finland). This study resolves the contradiction in the lifespan of satellite systems around galaxies, showing they are short-lived but maintain spatial coherence over billions of years.
Here is the overlay for this one:
The officially accepted version can be found on arXiv here and the Mastodon announcement is here:
New Publication at the Open Journal of Astrophysics: "Planes of satellites, at once transient and persistent" by Till Sawala (University of Helsinki, Finland)
And that concludes the update for this week. Will we keep the rate up next week? Tune in next Saturday to find out!
P.S. Thank you once again to the many people who have responded to the latest call for editors. The Editorial Board has grown substantially over the last few weeks – an up-to-date version can be found here – and there are still some people waiting to get onboard, so please bear with me!
As I predicted in last weekend’s update of activity at the Open Journal of Astrophysics, this morning I was able to publish the 500th paper at the Open Journal of Astrophysics. The overlay is here:
The authors of this paper are Harry Desmond of the Institute of Cosmology & Gravitation at the University of Portsmouth (UK) and Joseph Ramsey of the Philosophy Department at Carnegie Mellon University in the USA.You can find the officially accepted final version on arXiv here.
Congratulations to the authors – as a prize they each receive a year’s free subscription to the Open Journal of Astrophysics.
P.S. If you’re interested we published our 250th paper just over a year ago. If we keep this rate up we’ll have published over 1,000 papers by the time I retire…
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