Weekly Update from the Open Journal of Astrophysics – 07/02/2026

It’s Saturday once more so time for another update of activity at the Open Journal of Astrophysics. Since the last update we have published a further six papers, bringing the number in Volume 9 (2026) to 24 and the total so far published by OJAp up to 472.

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 announcement also show the DOI for each paper.

The first paper to report this week is “The Impact of Star Formation and Feedback Recipes on the Stellar Mass and Interstellar Medium of High-Redshift Galaxies” by Harley Katz (U. Chicago, USA), Martin P. Rey (U. Oxford, UK), Corentin Cadiou (Lund U., Sweden) Taysun Kimm (Yonsei U., Korea) and Oscar Agertz (Lund). This paper was published on Monday 2nd February 2026 in the folder Astrophysics of Galaxies. It introduces MEGATRON, a new model for galaxy formation simulations, highlighting that feedback energy controls star formation at high redshift and highlighting the importance of the interstellar medium.

The overlay is here:

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

https://fediscience.org/@OJ_Astro/116000695648050758

The second paper is “Photometric Redshifts in JWST Deep Fields: A Pixel-Based Alternative with DeepDISC” by Grant Merz (U. Illinois at Urbana-Champaign) and 6 others, all based in the USA. This paper was published on Monday February 2nd 2026 in the folder Instrumentation and Methods for Astrophysics. This paper explores the effectiveness of the DeepDISC machine learning algorithm in estimating photometric redshifts from near-infrared data, demonstrating its potential for larger image volumes and spectroscopic samples

The overlay for this one is here:

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

https://fediscience.org/@OJ_Astro/116000777572439111

Next, published on Wednesday 4th February in the folder Astrophysics of Galaxies, is “Inferring Interstellar Medium Density, Temperature, and Metallicity from Turbulent H II Regions” by Larrance Xing (U. Chicago, USA), Nicholas Choustikov (U. Oxford, UK), Harley Katz (U. Chicago) and Alex J. Cameron (DAWN, Denmark). This paper argues that supersonic turbulenc affects the interpretation of H II region properties, potentially impacting inferred metallicity, ionization, and excitation from in nebular emission lines, motivating more extensive modelling.

The overlay is here:

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

https://fediscience.org/@OJ_Astro/116011384659092223

The fourth paper this week, also published on Wednesday 4th February, but in the folder Solar and Stellar Astrophysics, is “A Systematic Search for Big Dippers in ASAS-SN” by B. JoHantgen, D. M. Rowan, R. Forés-Toribio, C. S. Kochanek, & K. Z. Stanek (Ohio State University, USA), B. J. Shappee (U. Hawaii, USA), Subo Dong (Peking University), J. L. Prieto Universidad Diego Portales, Chile) and Todd A. Thompson (Ohio State). This study identifies 4 new dipper stars and 15 long-period eclipsing binary candidates using ASAS-SN light curves and multi-wavelength data, categorizing them based on their characteristics.

Here is the overlay:

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

https://fediscience.org/@OJ_Astro/116011460612040834

Fifth, and next to last this week we have “Unveiling the drivers of the Baryon Cycles with Interpretable Multi-step Machine Learning and Simulations” by Mst Shamima Khanom, Benjamin W. Keller and Javier Ignacio Saavedra Moreno (U. Memphis, USA). This paper was published on Thursday 5th February 2026 in the folder Astrophysics of Galaxies. This study uses machine learning methods to understand how galaxies lose or retain baryons, highlighting the relationship between baryon fraction and various galactic measurements.

The overlay is here:

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

https://fediscience.org/@OJ_Astro/116016883984380622

Finally for this week we have “The Bispectrum of Intrinsic Alignments: II. Precision Comparison Against Dark Matter Simulations” by Thomas Bakx (Utrecht U., Netherlands), Toshiki Kurita (MPA Garching, Germany), Alexander Eggemeier (U. Bonn, Germany), Nora Elisa Chisari (Utrecht) and Zvonimir Vlah (Ruđer Bošković Institute, Croatia). This paper was accepted in December, but publication got delayed by the Christmas effect so was published on February 6th 2026, in the folder Cosmology and Nongalactic Astrophysics. This study uses N-body simulations to accurately measure three-dimensional bispectra of halo intrinsic alignments and dark matter overdensities, providing a method to determine higher order shape bias parameters.

The overlay is here:

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

https://fediscience.org/@OJ_Astro/116022562915557971

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

Weekly Update from the Open Journal of Astrophysics – 08/11/2025

It’s Saturday again, so it’s time for the usual update of the week’s new papers at the Open Journal of Astrophysics. Since the last update we have published another five papers, which brings the number in Volume 8 (2025) up to 168, and the total so far published by OJAp up to 403.

The first paper this week is “Maximizing Ariel’s Survey Leverage for Population-Level Studies of Exoplanets” by Nicolas B. Cowan and Ben Coull-Neveu (McGill University, Canada). This article was published in the folder Earth and Planetary Astrophysics on Tuesday 4th November 2025; it discusses various different schemes to select the mission reference sample for a notional three year transit spectroscopy survey with the European Space Agency’s Ariel mission

The overlay is here:

You can find the officially accepted version on arXiv here.

The Fediverse announcement is here:

Open Journal of Astrophysics

@[email protected]

New Publication at the Open Journal of Astrophysics: "Maximizing Ariel’s Survey Leverage for Population-Level Studies of Exoplanets" by Nicolas B. Cowan and Ben Coull-Neveu (McGill University, Canada)

https://doi.org/10.33232/001c.146656

The second paper of the week is “A substellar flyby that shaped the orbits of the giant planets” by Garett Brown (U. Toronto at Scarborough, Canada), Renu Malhotra (U. Arizona, USA) and Hanno Rein (U. Toronto at Scarborough, Canada). This article was published on Wednesday 5th November 2025, also in the folder Earth and Planetary Astrophysics. It argues that an ancient close encounter with a substellar object offers a plausible explanation for the origin of the moderate eccentricities and inclinations of the giant planets.

The overlay is here:

You can find the official version of this one on arXiv here. The federated announcement on Mastodon is here:

Open Journal of Astrophysics

@[email protected]

New Publication at the Open Journal of Astrophysics: "A substellar flyby that shaped the orbits of the giant planets" by Garett Brown (U. Toronto at Scarborough, Canada), Renu Malhotra (U. Arizona, USA) and Hanno Rein (U. Toronto at Scarborough, Canada)

https://doi.org/10.33232/001c.146688

Next one up is “The Potential Impact of Primordial Black Holes on Exoplanet Systems” by Garett Brown (U. Toronto at Scarborough), Linda He (Harvard U., USA),  and James Unwin (U. Illinois Chicago, USA). This one was also published on Wednesday 5th November 2025, but in the folder Astrophysics of Galaxies. This one is an exploration of the possibility that primordial black holes (PBHs) in our Galaxy, might impact the orbits of exoplanets. The overlay is here:

You can find the official accepted version on arXiv here. The fediverse announcement is here:

Open Journal of Astrophysics

@[email protected]

New Publication at the Open Journal of Astrophysics: "The Potential Impact of Primordial Black Holes on Exoplanet Systems" by Garett Brown (U. Toronto at Scarborough), Linda He (Harvard U., USA), James Unwin (U. Illinois Chicago, USA)

https://doi.org/10.33232/001c.146689

The fourth paper to report is “The Unhurried Universe: A Continued Search for Long Term Variability in ASAS-SN” by Sydney Petz, C. S. Kochanek & K. Z. Stanek (Ohio State U., USA), Benjamin J. Shappee (U. Hawaii, USA), Subo Dong (Peking University, China), J. L. Prieto (Universidad Diego Portales, Chile) and Todd A. Thompson (Ohio State U., USA). This one was also published on Wednesday November 5th 2025, but in the folder Solar and Stellar Astrophysics.  It describes the discovery and investigation of slowly-varying sources in the All Sky Automated Survey for SuperNovae (ASAS-AN) leading to the identification of 200 new variable stars. The overlay is here:

You can find the official published version on arXiv here. The Fediverse announcement follows:

Open Journal of Astrophysics

@[email protected]

New Publication at the Open Journal of Astrophysics: "The Unhurried Universe: A Continued Search for Long Term Variability in ASAS-SN" by Sydney Petz, C. S. Kochanek & K. Z. Stanek (Ohio State U., USA), Benjamin J. Shappee (U. Hawaii, USA), Subo Dong (Peking University, China), J. L. Prieto (Universidad Diego Portales, Chile) and Todd A. Thompson (Ohio State U., USA)

https://doi.org/10.33232/001c.146690

The fifth and final paper for this week is “Measuring the splashback feature: Dependence on halo properties and history” by Qiaorong S. Yu (Oxford U., UK) and 9 others based in the UK and USA. This was published on Friday 7th November 2025 in the folder Cosmology and Nongalactic Astrophysics. It discusses how the properties of “splashback” features in halo profiles relate to the halo’s assembly history (e.g. mass accretion rate and most recent merger time). The overlay is here:

The officially accepted version can be found on arXiv here. The Fediverse announcement is here:

Open Journal of Astrophysics

@[email protected]

New Publication at the Open Journal of Astrophysics: "Measuring the splashback feature: Dependence on halo properties and history" by Qiaorong S. Yu (Oxford U., UK) and 9 others based in the UK and USA.

https://doi.org/10.33232/001c.146824

That’s all the papers for this week. I’ll do another report next Saturday.

#Ariel #arXiv241204583v2 #arXiv250606429v2 #arXiv250705389v3 #arXiv250707174v2 #arXiv250722102v2 #CosmologyAndNonGalacticAstrophysics #DarkMatterHaloes #DiamondOpenAccess #DiamondOpenAccessPublishing #EarthAndPlanetaryAstrophysics #eccentricity #EuropeanSpaceAgency #exoplanets #ExtrrasolarPlanets #galaxyFormation #galaxyHaloes #GiantPlanets #OpenAccess #OpenJournalOfAstrophysics #primordialBlackHoles #Splashback #TheOpenJournalOfAstrophysics

Weekly Update from the Open Journal of Astrophysics – 26/07/2025

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 first paper to report is “Non-equilibrium ionization in the multiphase circumgalactic medium – impact on quasar absorption-line analyses” by Suyash Kumar and Hsiao-Wen Chen (University of Chicago, USA). This was published on Tuesday 22nd July 2025 in the folder Astrophysics of Galaxies. It discusses time-dependent photoionization (TDP) models that self-consistently solve for the ionization state of rapidly cooling gas irradiated by the extragalactic ultraviolet background (UVB) and the application thereof to observed systems.

The overlay is here:

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.

You can find the final version on arXiv here.

The last article published this week is “21 Balmer Jump Street: The Nebular Continuum at High Redshift and Implications for the Bright Galaxy Problem, UV Continuum Slopes, and Early Stellar Populations” by Harley Katz of the University of Chicago, and 13 others based in the USA, UK, Germany, Denmark and Austria. This discusses the implications of extreme nebular emission for the spectroscopic properties of galaxies, especially at high redshift. It was published on Friday 25th July in the folder Astrophysics of Galaxies.

The overlay is here:

You can find the officially-accepted version on arXiv here.

And that’s all the papers for this week. I’ll do another update next Saturday, when we’ll be into August.

#arXiv241007084v2 #arXiv250113170v2 #arXiv250410571v2 #arXiv250415468v2 #arXiv250715963v1 #AstrophysicsOfGalaxies #CircumgalacticMedium #CosmicReionization #Cosmology #CosmologyAndNonGalacticAstrophysics #DiamondOpenAccess #Euclid #EuclidDeepFieldNorth #fastRadioBursts #galaxyHaloes #generativeAI #LOFAR #NebularEmission #OpenJournalOfAstrophysics #subhaloes #TheOpenJournalOfAstrophysics #UltravioletSpectroscopy