In a vain attempt to convince my readership that I know anything about observational astronomy, I thought I’d share this image of the central regions of the Perseus Cluster (also known as Abell 426) taken by my final-year project students:
Picture Credit: Ben Doyle
The image was taken last November using the 1.20m reflecting telescope at the Observatoire de Haute-Provence where the final-year astrophysics students from Maynooth spent a week last November on a field trip taking various observations. The exposure was 240 seconds and the field of view is about 15 arcminutes on a side. Most of the objects in the image are galaxies, rather than stars.
I asked my students to look at this cluster (which is about 10 degrees across), partly because it appears near the Zenith in November so would be a good target, partly because it is nearby so the galaxies in it are therefore quite bright, and partly because it was observed by Euclid and featured among the Early Release Observations. The Euclid telescope is also 1.20m in diameter, but because it has a very fancy camera and is in space, Euclid reveals far more galaxies but I was nevertheless impressed at how well this turned out!
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.
As an Astronomist I am often asked “How do they calculate the date of Easter?”, so here goes.
The simple answer is that Easter Sunday is on the first Sunday after the first full Moon on or after the Vernal equinox. The Vernal Equinox took place this year on March 20th and the first full moon after that was on April 2nd.
I say “simple” answer above because it isn’t quite how the date of Easter is reckoned for purposes of the liturgical calendar.
For a start, the ecclesiastical calculation of the date for Easter – the computus – assumes that the Vernal Equinox is always on March 21st, while in reality these days it is more frequently 20th March, like this year.
On top of that there’s the issue of what reference time and date to use. The equinox is a precisely timed astronomical event but it occurs at different times and possibly on different days in different time zones. Likewise the full Moon. In the ecclesiastical calculation the “full moon” does not currently correspond directly to any astronomical event, but is instead the 14th day of a lunar month, as determined from tables (see below). It may differ from the date of the actual full moon by up to two days.
There have been years (1974, for example) where the official date of Easter does not coincide with the date determined by the simple rule given above. The actual rule is a complicated business involving Golden Numbers and Metonic cycles and whatnot.
Here is an excerpt from the Book of Common Prayer that shows Anglicans how to determine the date of Easter for any year up to 2199:
The calculations are based on the approximately 19-year metonic cycle, which is why the above table will not work indefinitely
For this year we find that (2026+1=2027) ÷19=106 with a remainder of 13 (106 × 19 being 2014). The Golden Number for this year is therefore 13, or XIII in the Table. This gives the date of the Paschal Full Moon, which occured this year on 2nd April, which is indeed the day in the centre column next to XIII in the left-hand column in the table. The Sunday Letter is determined by the remainder of (2026+506+6)÷7, which is 4, so this year’s Sunday Letter is D. The date of Easter Sunday is given by the entry in the centre column next to the first occurrence of D in the right-hand column after the Golden Number XIII appears in the left-hand column, i.e. April 5th. I hope this clarifies the situation.
Regular readers of this blog might remember that last year I did a post about a very comprehensive review article which had appeared on arXiv with the title Hitchhiker’s Guide to the Swampland: The Cosmologist’s Handbook to the string-theoretical Swampland Programme. The article is by Kay Lehnert (who happens to be my PhD student). Well, that paper was published last Saturday (28th March 2026) in the journal Fortschritte der Physik (which I translate roughly as “Advances in Physics”, but whose official English title seems to be “Progress of Physics”). Anyway, it is available (and indeed openly accessible) here. And, if you don’t believe me, here’s a grab of the front page showing the deets (as you young people say):
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!
Some time ago I posted an item about Doggerland which is not (as you might have imagined) a theme park devoted to outdoor sexual activities, but an area now submerged beneath the North Sea that connected Great Britain to continental Europe during and after the last glacial period.
About 12,000 years ago at the start of the Holocene Era, it is thought that the area now covered by the North Sea looked something like this:
(Picture credit: this website). Obviously the cities marked on the map were not there at the time! Britain was connected to the European mainland, although much of the land mass was under glaciers. At the end of the last ice age the glaciers retreated, sea levels rose and the area once covered by Doggerland was submerged. It is thought that this happened around 8500 years ago. Great Britain has been separated from the continent by less than 10,000 years.
Doggerland gets its name from the Dogger Bank, a huge sandbank off the North-Eastern coast of England which is thought to be a glacial moraine left behind by the retreating ice sheet. The Dogger bank lies about 60 miles from the coast, and is about 60 miles wide by 100 miles long. The water is quite shallow – typically 20 metres deep – and is a well-known fishing area. Its name derives from old Dutch fishing vessels called doggers who specialised in catching cod. Modern fishing boats trawlers operating at the Dogger Bank frequently bring up bits of ancient animals (including mammoth and rhinoceros) as well as prehistoric human artefacts, showing that the area was at one time inhabited.
I don’t think anybody knows exactly how long it took Doggerland to become submerged, but it may well have involved one or more catastrophic flooding events.
Well, by way of a sort of update here is a short video that suggests that the archaeological and geological clues indicate that the end of Doggerland was associated with one particularly huge event.
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!
Loughcrew Cairn: for a few days on and around the Vernal Equinox the rays of the rising Sun penetrate the passage and illuminate the back stone.
Just a quick note to mention that the Vernal Equinox (Spring Equinox) in the Northern hemisphere happens this afternoon, Friday 20th March 2026, at 14.46 UTC (which is 2.46 pm local time here in Ireland. Many people in the Northern hemisphere regard the Vernal Equinox as the first day of Spring, atlhough round these parts that is taken to be 1st February (Imbolg). Of course in the Southern hemisphere, this is the Autumnal Equinox.
The date of the Vernal Equinox is often given as 21st March, but in fact it has only been on 21st March twice this century so far (2003 and 2007); it was on 20th March in 2008, has been on 20th March every spring from then until now, and will be until 2044 (when it will be on March 19th). I’ll be retired by then.
Anyway, people sometimes ask me how one can define the `equinox’ so precisely when surely it just refers to a day on which day and night are of equal length, implying that it’s a day not a specific time? The answer is that the equinox is defined by a specific event, the event in question being when the plane defined by Earth’s equator passes through the centre of the Sun’s disk (or, if you prefer, when the centre of the Sun passes through the plane defined by Earth’s equator). Day and night are not necessarily exactly equal on the equinox, but they’re the closest they get. From now until the Autumnal Equinox, days in the Northern hemisphere will be longer than nights, and the days will continue get longer until the Summer Solstice on June 21st before beginning to shorten again.
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 four papers, bringing the number in Volume 9 (2026) to 51 and the total so far published by OJAp up to 499. I hoped we would reach 500 this week, but that milestone will have to wait. We have however passed the 50 mark for this year, so we have now published more papers so far in 2026 than we published in all of 2023.
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: "Effect of temperature on the structure of porous dust aggregates formed by coagulation" by Lucas Kolanz, Davide Lazzati and Job Guidos (Oregon State University, USA)
The second paper for this week is “Intrinsic alignment of disks and ellipticals across hydrodynamical simulations” by M. L. van Heukelum and N. E. Chisari (Utrecht University, The Netherlands). This is one of two papers published on Tuesday 10th March. This one is in the folder Astrophysics of Galaxies: it examines the inconsistent correlations between galaxy positions and shapes, comparing disk and elliptical shapes in different simulations. The results highlight the importance of sub-grid physics at non-linear scales.
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: "Intrinsic alignment of disks and ellipticals across hydrodynamical simulations" by M. L. van Heukelum and N. E. Chisari (Utrecht University, The Netherlands)
Next one up is “A Comparison of Galacticus and COZMIC WDM Subhalo Populations” by Jack Lonergan (U. Southern California), Andrew Benson (Carnegie Observatories) and Xiaolong Du (UCLA), all based in the USA. This paper was published on 10th March 2026 in the folder Cosmology and Nongalactic Astrophysics. The study compares warm dark matter subhalo populations using the Galacticus model and COZMIC simulations, finding both can reliably reproduce these distributions, with Galacticus offering computational efficiency.Abstractfor A Comparison of Galacticus and COZMIC WDM Subhalo Populations.
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 Comparison of Galacticus and COZMIC WDM Subhalo Populations" by Jack Lonergan (U. Southern California), Andrew Benson (Carnegie Observatories) and Xiaolong Du (UCLA), all based in the USA.
And finally for this week we have “Simulation-Based Inference for Probabilistic Galaxy Detection and Deblending” by Ismael Mendoza (U. Maryland, USA) and 7 others (all based in the USA) on behalf of the LSST Dark Energy Science Collaboration. This was published on Thursday March 12th in the folder Instrumentation and Methods for Astrophysics. The article introduces the Bayesian Light Source Separator (BLISS), for detecting and measuring galaxy properties in wide-field cosmological surveys. BLISS demonstrates improved performance, particularly for faint and blended objects.
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: "Simulation-Based Inference for Probabilistic Galaxy Detection and Deblending" by Ismael Mendoza (U. Maryland, USA) and 7 others (all based in the USA) on behalf of the LSST Dark Energy Science Collaboration
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!
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In the Dark 